CC2400SK [TI]

2.4 GHz Low-Power RF Transceiver; 2.4 GHz的低功耗RF收发器
CC2400SK
型号: CC2400SK
厂家: TEXAS INSTRUMENTS    TEXAS INSTRUMENTS
描述:

2.4 GHz Low-Power RF Transceiver
2.4 GHz的低功耗RF收发器

文件: 总84页 (文件大小:955K)
中文:  中文翻译
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CC2400  
CC2400  
2.4 GHz Low-Power RF Transceiver  
Applications  
2.4 GHz MHz ISM/SRD band systems  
Game controllers  
Sports and leisure equipment  
Wireless audio  
PC peripherals  
Advanced toys  
Product Description  
and error detection reducing the workload  
on the host microcontroller.  
The CC2400 is a true single-chip 2.4 GHz  
RF transceiver designed for low-power  
and low-voltage wireless applications. The  
RF transceiver is integrated with  
a
The main operating parameters of CC2400  
can be programmed via an SPI-bus. In a  
typical system CC2400 will be used  
together with a microcontroller and a few  
external, passive components.  
baseband modem supporting data rates  
up to 1 Mbps.  
The CC2400 is a low-cost, highly integrated  
solution  
enabling  
robust  
wireless  
CC2400 is based on Chipcon’s SmartRF-  
03 technology in 0.18 µm CMOS.  
communication in the 2.4 - 2.4835 GHz  
unlicensed ISM band. It is intended for  
systems compliant with world-wide  
regulations covered by EN 300 440  
(Europe), CFR47 Part 15 (US) and ARIB  
STD-T66 (Japan).  
Targeting a wide range of applications at  
2.4 GHz, the CC2400 supports over-the-air  
data rates of 10 kbps, 250 kbps and  
1 Mbps without requiring any modifications  
to the hardware.  
The CC2400 provides extensive hardware  
support for packet handling, data  
buffering, burst transmissions, data coding  
Key Features  
True single-chip 2.4 GHz RF  
transceiver with baseband modem  
10 kbps, 250 kbps and 1 Mbps over-  
the-air data rates  
Low current consumption (RX: 24 mA)  
Low core supply voltage (1.8 V)  
Programmable output power  
No external RF switch / filter needed  
I/Q low-IF receiver  
Packet handling hardware  
Data buffering  
Digital RSSI output  
Small size (QFN 48 package), 7x7 mm  
Reference design complies with EN  
300 328, EN 300 440, FCC CFR47 part  
15 and ARIB STD-T66  
Powerful and flexible development  
tools available  
Easy-to-use software for generating  
the CC2400 configuration data  
I/Q direct up-conversion transmitter  
Few external components  
FIFO allows bursting of data  
This document contains information on a pre-production product. Specifications and information herein are subject to  
change without notice.  
SWRS042A  
Page 1 of 83  
CC2400  
Table of contents  
1
2
3
4
5
6
7
8
ABBREVIATIONS.............................................................................................................. 4  
FEATURES........................................................................................................................ 5  
ABSOLUTE MAXIMUM RATINGS.................................................................................... 6  
OPERATING CONDITIONS .............................................................................................. 6  
ELECTRICAL SPECIFICATIONS ..................................................................................... 7  
GENERAL CHARACTERISTICS ...................................................................................... 7  
RF TRANSMIT SECTION.................................................................................................. 8  
RF RECEIVE SECTION..................................................................................................... 9  
AFC SECTION................................................................................................................. 10  
RSSI / CARRIER SENSE SECTION............................................................................ 11  
IF SECTION.................................................................................................................. 11  
FREQUENCY SYNTHESIZER SECTION.................................................................... 11  
DIGITAL INPUTS/OUTPUTS....................................................................................... 12  
PIN ASSIGNMENT....................................................................................................... 13  
CIRCUIT DESCRIPTION ............................................................................................. 15  
APPLICATION CIRCUIT.............................................................................................. 17  
9
10  
11  
12  
13  
14  
15  
16  
16.1  
INPUT / OUTPUT MATCHING ....................................................................................... 17  
BIAS RESISTOR ........................................................................................................ 17  
CRYSTAL................................................................................................................. 17  
DIGITAL I/O ............................................................................................................. 17  
POWER SUPPLY DECOUPLING AND FILTERING ............................................................ 17  
POWER SUPPLY SWITCHING...................................................................................... 17  
CONFIGURATION OVERVIEW................................................................................... 20  
CONFIGURATION SOFTWARE.................................................................................. 20  
4-WIRE SERIAL CONFIGURATION INTERFACE...................................................... 21  
OVERVIEW OF CONFIGURATIONS AND HARDWARE SUPPORT ........................ 24  
MICROCONTROLLER INTERFACE AND PIN CONFIGURATION ........................... 25  
CONFIGURATION INTERFACE..................................................................................... 25  
SIGNAL INTERFACE IN UN-BUFFERED MODE................................................................ 25  
GENERAL CONTROL AND STATUS PINS....................................................................... 25  
DATA BUFFERING...................................................................................................... 27  
BUFFERED MODE ..................................................................................................... 27  
BUFFERED MODE HARDWARE SUPPORT..................................................................... 27  
PACKET HANDLING HARDWARE SUPPORT.......................................................... 29  
DATA PACKET FORMAT ............................................................................................. 29  
ERROR DETECTION .................................................................................................. 29  
HARDWARE INTERFACE ............................................................................................ 31  
DATA / LINE ENCODING............................................................................................ 31  
DATA ENCODING IN BUFFERED MODE......................................................................... 31  
DATA ENCODING IN UN-BUFFERED MODE ................................................................... 32  
RADIO CONTROL STATE MACHINE ........................................................................ 34  
POWER MANAGEMENT FLOW CHART ................................................................... 36  
FSK MODULATION FORMATS .................................................................................. 38  
BUILT-IN TEST PATTERN GENERATOR.................................................................. 38  
RECEIVER CHANNEL BANDWIDTH ......................................................................... 39  
DATA RATE PROGRAMMING.................................................................................... 40  
DEMODULATOR, BIT SYNCHRONIZER AND DATA DECISION............................. 41  
AUTOMATIC FREQUENCY CONTROL ..................................................................... 42  
LINEAR IF AND AGC SETTINGS ............................................................................... 43  
RSSI.............................................................................................................................. 44  
CARRIER SENSE ........................................................................................................ 45  
INTERFACING AN EXTERNAL LNA OR PA ............................................................. 45  
GENERAL PURPOSE / TEST OUTPUT CONTROL PINS......................................... 45  
FREQUENCY PROGRAMMING.................................................................................. 47  
16.2  
16.3  
16.4  
16.5  
16.6  
17  
18  
19  
20  
21  
21.1  
21.2  
21.3  
22  
22.1  
22.2  
23  
23.1  
23.2  
23.3  
24  
24.1  
24.2  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
SWRS042A  
Page 2 of 83  
CC2400  
38.1  
38.2  
TRANSMIT MODE ...................................................................................................... 47  
RECEIVE MODE ........................................................................................................ 47  
ALTERNATE TX IF SETTING ..................................................................................... 47  
VCO .............................................................................................................................. 48  
VCO SELF-CALIBRATION.......................................................................................... 48  
OUTPUT POWER PROGRAMMING........................................................................... 48  
CRYSTAL OSCILLATOR ............................................................................................ 49  
INPUT / OUTPUT MATCHING..................................................................................... 50  
TYPICAL PERFORMANCE GRAPHS......................................................................... 50  
SYSTEM CONSIDERATIONS AND GUIDELINES ..................................................... 53  
SRD REGULATIONS.................................................................................................. 53  
FREQUENCY HOPPING AND MULTI-CHANNEL SYSTEMS................................................ 53  
DATA BURST TRANSMISSIONS ................................................................................... 53  
CONTINUOUS TRANSMISSIONS .................................................................................. 53  
CRYSTAL DRIFT COMPENSATION ............................................................................... 53  
SPECTRUM EFFICIENT MODULATION .......................................................................... 54  
LOW LATENCY SYSTEMS........................................................................................... 54  
LOW COST SYSTEMS ................................................................................................ 54  
BATTERY OPERATED SYSTEMS.................................................................................. 54  
39  
40  
41  
42  
43  
44  
45  
46  
46.1  
46.2  
46.3  
46.4  
46.5  
46.6  
46.7  
46.8  
46.9  
46.10  
INCREASING OUTPUT POWER .................................................................................... 54  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
PCB LAYOUT RECOMMENDATIONS ....................................................................... 56  
ANTENNA CONSIDERATIONS .................................................................................. 57  
CONFIGURATION REGISTERS ................................................................................. 58  
PACKAGE DESCRIPTION (QFN48)........................................................................... 76  
RECOMMENDED LAYOUT FOR PACKAGE (/QFN48)............................................. 77  
PACKAGE THERMAL PROPERTIES......................................................................... 77  
SOLDERING INFORMATION...................................................................................... 77  
IC MARKING................................................................................................................ 78  
PLASTIC TUBE SPECIFICATION............................................................................... 80  
CARRIER TAPE AND REEL SPECIFICATION .......................................................... 80  
ORDERING INFORMATION........................................................................................ 80  
GENERAL INFORMATION.......................................................................................... 81  
DOCUMENT HISTORY ............................................................................................... 81  
PRODUCT STATUS DEFINITIONS................................................................................ 82  
DISCLAIMER............................................................................................................. 82  
TRADEMARKS .......................................................................................................... 82  
LIFE SUPPORT POLICY ............................................................................................. 82  
ADDRESS INFORMATION.......................................................................................... 83  
58.1  
58.2  
58.3  
58.4  
58.5  
59  
SWRS042A  
Page 3 of 83  
CC2400  
1
Abbreviations  
ACP  
Adjacent Channel Power  
Adjacent Channel Rejection  
Analog-to-Digital Converter  
Automatic Frequency Correction  
Automatic Gain Control  
Bit Error Rate  
ACR  
ADC  
AFC  
AGC  
BER  
BOM  
bps  
Bill Of Materials  
bits per second  
BT  
Bandwidth-Time product (for GFSK)  
Cyclic Redundancy Check  
Carrier Sense Multiple Access  
CRC  
CSMA  
CSMA / CA  
DAC  
ESR  
FH  
Carrier Sense Multiple Access / Collision Avoidance  
Digital-to-Analog Converter  
Equivalent Series Resistance  
Frequency Hopping  
FHSS  
FIFO  
FS  
Frequency Hopping Spread Spectrum  
First In First Out (queue)  
Frequency Synthesizer  
Frequency Shift Keying  
Gaussian Frequency Shift Keying  
Intermediate Frequency  
Industrial Scientific Medical  
kilo bits per second  
FSK  
GFSK  
IF  
ISM  
kbps  
LNA  
Mbps  
MCU  
NRZ  
PA  
Low Noise Amplifier  
Mega bits per second  
Micro Controller Unit  
Non Return to Zero  
Power Amplifier  
PD  
Phase Detector  
PCB  
PN9  
PLL  
Printed Circuit Board  
Pseudo-random Bit Sequence (9-bit)  
Phase Locked Loop  
PRN  
PRNG  
RF  
Pseudo Random Number  
Pseudo Random Number Generator  
Radio Frequency  
RSSI  
RX  
SPI  
Received Signal Strength Indicator  
Receive (mode)  
Serial Peripheral Interface  
Short Range Device  
SRD  
TBD  
TDMA  
TX  
To Be Decided/Defined  
Time Division Multiple Access  
Transmit (mode)  
VCO  
VGA  
Voltage Controlled Oscillator  
Variable Gain Amplifier  
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Page 4 of 83  
CC2400  
2
Features  
2400 – 2483 MHz RF transceiver  
Packet handling hardware support  
GFSK and FSK modulation  
Very low current consumption (RX:  
24 mA)  
Preamble  
generator  
with  
programmable length  
Programmable  
synchronization  
Over-the-air data rates of 10 kbps,  
250 kbps and 1 Mbps  
word insertion/detection  
CRC computation over the data  
field  
High sensitivity (-87 dBm @ 1Mbps,  
BER=10-3)  
Agile frequency synthesizer (40 us  
settling time)  
8B/10B line coding option  
Data buffering  
On-chip VCO, LNA and PA  
Low core supply voltage (1.6-2.0 V)  
Flexible  
(1.6–3.6 V) to match the signal  
levels of the interfacing  
microcontroller  
Programmable output power  
I/Q low-IF receiver  
I/Q direct up-conversion transmitter  
32 byte FIFO  
Provides for flexible communication  
with the host controller.  
Burst transmission reduces the  
average power consumption.  
I/O  
supply  
voltage  
Powerful and flexible development  
tools available  
Fully equipped development kit  
Demonstration board reference  
design with microcontroller code  
Few external components  
Only reference crystal and a few  
passives needed  
No external filters needed  
Easy-to-use  
SmartRF  
Studio  
software for generating the CC2400  
configuration data  
Programmable baseband modem  
Small size (QFN 48 package) 7 x 7 mm  
4-wire SPI interface  
Serial clock up to 20 MHz  
Digital RSSI output  
Reference design complies with EN  
300 328, EN 300 440, FCC CFR47 part  
15 and ARIB STD-T66  
SWRS042A  
Page 5 of 83  
CC2400  
3
Absolute Maximum Ratings  
Parameter  
Min.  
0.3  
Max.  
2.0  
Units  
V
Condition  
Supply voltage, chip core,  
AVDD/DVDD1.8=VDD  
Supply voltage (DVDD3.3=VDDIO), digital I/O  
Voltage on any pin, core  
0.3  
0.3  
3.6  
VDD+0.3,  
max 2.0  
VDDIO+0.3,  
max 3.6  
10  
V
V
Voltage on any pin, digital I/O (pin no. 27-35)  
0.3  
V
Input RF level  
Storage temperature range  
Reflow solder temperature  
dBm  
°C  
°C  
50  
150  
260  
T = 10 s  
NOTE:  
The supply voltage to the chip core (AVDD/DVDD1.8) should not be switched off when the digital IO (DVDD3.3)  
supply voltage is still applied to the chip. If this is done, a large current will flow inside the CC2400 and the chip may  
be damaged as a result.  
If the core supply needs to be switched off to lower the power consumption, please see page 17 for a suggested  
solution.  
The absolute maximum ratings given  
above should under no circumstances be  
violated. Stress exceeding one or more of  
the limiting values may cause permanent  
damage to the device.  
Caution! ESD sensitive device.  
Precaution should be used when handling  
the device in order to prevent permanent  
damage.  
4
Operating Conditions  
Parameter  
Min.  
Typ.  
Max.  
Unit  
Condition  
Supply voltage, chip core,  
1.6  
2.0  
V
AVDD/DVDD1.8  
Supply voltage (DVDD3.3), digital  
I/O, VDDIO  
1.6  
3.6  
V
The digital I/O voltage (DVDD3.3  
pin) must match the interfacing  
circuit.  
Recommended supply voltage, chip  
core, AVDD/DVDD1.8  
Recommended supply voltage  
(DVDD3.3), digital I/O  
Operating ambient temperature  
range  
1.8V  
1.8V/  
3.3V  
40  
85  
°C  
SWRS042A  
Page 6 of 83  
CC2400  
5
Electrical Specifications  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
Current Consumption,  
Power Down mode (OFF)  
1.5  
1.2  
5
Oscillator core off  
µA  
Current Consumption,  
Idle mode (IDLE)  
mA  
Current Consumption,  
Frequency synthesizer (FS_ON)  
6.3  
24  
mA  
mA  
Current Consumption,  
Receive mode  
Current Consumption,  
Transmit mode:  
P=25 dBm  
P=5 dBm  
P=0 dBm  
11  
15  
19  
mA  
mA  
mA  
The output power is delivered  
differentially to a 50single-  
ended load through a balun, see  
also p. 50.  
Current Consumption, crystal  
oscillator core  
38  
16 MHz, 16 pF load crystal  
µA  
Table 1 Electrical specifications  
6
General Characteristics  
Tc = 25°C, AVDD/DVDD1.8 = 1.8 V, DVDD3.3 = 3.3V (digital I/O) if nothing else stated. Measured on Chipcon’s  
CC2400EM reference design.  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
RF Frequency Range  
2400  
2483  
MHz  
Programmable in 1 MHz channel  
steps.  
Data rate  
10  
250  
1
kbps  
kbps  
Mbps  
Data rate is  
programmable/selectable, see  
page 40  
Table 2 General characteristics  
SWRS042A  
Page 7 of 83  
CC2400  
7
RF Transmit section  
Tc = 25°C, AVDD/DVDD1.8 = 1.8 V, DVDD3.3 = 3.3V (digital I/O) if nothing else stated. Measured on Chipcon’s  
CC2400EM reference design.  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
Binary FSK frequency deviation  
0
250  
500  
The frequency corresponding to  
±kHz  
the digital "0" is denoted f0, while  
f1 corresponds to a digital "1".  
The frequency deviation is given  
by fd=±(f1f0)/2. The RF carrier  
frequency, fc, is then given by  
fc=(f0+f1)/2.  
Nominal output power  
0
dBm  
dB  
Default settings.  
Power delivered to a 50 single-  
ended load through a balun. The  
output power is programmable in  
8 steps.  
Programmable output power range  
20 dB bandwidth  
25  
Maximum output power.  
Modulation is 1 Mbps, NRZ data,  
± 250 kHz frequency deviation.  
FSK  
GFSK  
1.2  
1.0  
MHz  
MHz  
Adjacent Channel Power (ACP)  
Maximum output power.  
Modulation is 1 Mbps, NRZ data,  
± 250 kHz frequency deviation.  
Measured at 2 MHz offset.  
FSK  
GFSK  
-30  
-43  
dBc  
dBc  
Harmonics  
At max output power delivered to  
50 single-ended load through a  
balun. Carrier modulated with  
pseudo-random data. See p.50.  
2nd order harmonic  
3rd order harmonic  
-41  
-54  
dBm  
dBm  
Spurious emission  
30 - 1000 MHz  
1– 12.75 GHz  
1.8 – 1.9 GHz  
5.15 – 5.3 GHz  
Maximum output power.  
Modulation is 1 Mbps FSK, NRZ  
data, ±250 kHz frequency  
deviation.  
-65  
-41  
-69  
-65  
-36  
-30  
-47  
-47  
dBm  
dBm  
dBm  
dBm  
Complying with EN 300 440,  
CFR47 Part 15 and ARIB STD-  
T66  
Optimum load impedance  
110  
+ j130  
Differential impedance as seen  
from the RF-port (RF_P and  
RF_N) towards the antenna. For  
matching details see “Input/  
output matching” page 50 as well  
as the application circuit  
description on page 17.  
Table 3 Transmit characteristics  
SWRS042A  
Page 8 of 83  
CC2400  
8
RF Receive section  
Tc = 25°C, AVDD/DVDD1.8 = 1.8 V, DVDD3.3 = 3.3V (digital I/O) if nothing else stated. Measured on Chipcon’s  
CC2400EM reference design.  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
Receiver Sensitivity at BER = 103  
Measured in a 50 Ohm single-  
ended load through a balun. FSK,  
NRZ mode used.  
1 Mbps, 1 MHz channel BW  
250 kbps, 1 MHz channel BW  
10 kbps, 500 kHz channel BW  
-87  
-91  
-101  
dBm  
dBm  
dBm  
±250 kHz frequency deviation  
±250 kHz frequency deviation  
±125 kHz frequency deviation  
Saturation (maximum input level)  
3
dBm  
Maximum gain in LNA.  
NRZ coded data, BER = 103  
Co-channel rejection  
-10  
dB  
1 Mbps wanted signal 10 dB  
above the sensitivity level,  
interferer modulated like signal  
(pseudo-random FSK, ± 250 kHz  
deviation), interferer at operating  
frequency, BER = 103  
Adjacent channel rejection (ACR)  
FSK wanted signal 10 dB above  
the sensitivity level, 1 MHz  
channel spacing, interferer  
modulated like signal (pseudo-  
random FSK, ± 250 kHz  
deviation) at adjacent channel,  
BER = 103  
1 Mbps  
250 kbps  
0
12  
dB  
dB  
Image channel rejection  
FSK wanted signal 10 dB above  
the sensitivity level, interferer  
modulated like signal (pseudo-  
random FSK, ± 250 kHz  
1 Mbps  
250 kbps  
21  
39  
dB  
dB  
deviation) at image frequency,  
BER = 103. The image channel  
is centered 2MHz below the  
center frequency of the desired  
channel.  
Selectivity (C/I)  
(In-band channel rejection)  
+ 2MHz  
± 3MHz  
± 4MHz  
± 5MHz  
± 10MHz  
± 20 MHz  
± 50MHz  
20  
41  
50  
52  
55  
56  
59  
dB  
dB  
dB  
dB  
dB  
dB  
dB  
1Mbps FSK wanted signal at  
2441 MHz, 3 dB above the  
sensitivity level (except + 2 MHz,  
which is 10 dB above the  
sensitivity limit), jammer  
modulated like signal (pseudo-  
random, ± 250 kHz deviation) at  
± 2-39 MHz in 1 MHz steps  
offset, BER = 103. Adjacent  
channels and image channel are  
excluded.  
+ 2 MHz  
± 3 MHz  
± 4 MHz  
± 5 MHz  
± 10 MHz  
± 20 MHz  
± 50 MHz  
48  
50  
55  
56  
59  
60  
64  
dB  
dB  
dB  
dB  
dB  
dB  
dB  
250 kbps FSK wanted signal at  
2441 MHz, 3 dB above the  
sensitivity level (except + 2 MHz,  
which is 10 dB above the  
sensitivity limit), jammer  
modulated like signal (pseudo-  
random, ± 250 kHz deviation) at  
± 2-39 MHz in 1 MHz steps  
offset, BER = 103. Adjacent  
channels and image channel are  
excluded.  
SWRS042A  
Page 9 of 83  
CC2400  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
Blocking / Desensitization*  
(*out-of-band spurious response  
rejection)  
0.3 – 2.0 GHz  
71  
50  
49  
76  
dB  
dB  
dB  
dB  
1 Mbps FSK wanted signal 3 dB  
above the sensitivity level, sine-  
wave interfering signal, BER =  
103.  
2.0 – 2.399 GHz  
2.498 – 3.0 GHz  
3 – 12.75 GHz  
Input IIP3  
Measured directly by applying  
two tones and measuring the  
resulting difference tone  
amplitude.  
Out of band  
In band  
-5  
-17  
dBm  
dBm  
Image frequency suppression  
56  
dB  
Ratio between sensitivity for a  
signal at the image frequency and  
the sensitivity in the wanted  
channel with an inverted signal.  
The image frequency is centered  
-2 MHz from the center of the  
wanted channel. The signal  
source is 1Mbps, NRZ coded  
data, ±250 kHz frequency  
deviation, signal level for BER =  
103  
Spurious reception  
80  
dB  
Ratio between the sensitivity for  
an unwanted frequency and the  
sensitivity in the wanted channel.  
The signal source is a 1 Mbps,  
NRZ coded data, ±250 kHz  
frequency deviation, swept over  
all frequencies 2400 – 2483.5  
MHz. Signal level for BER = 103  
Adjacent channels and image  
channel are excluded.  
Spurious emission  
< 1 GHz  
1 – 12.75 GHz  
Complying with EN 300 440,  
CFR47 Part 15 and ARIB STD-  
T66  
70  
56  
-57  
-47  
dBm  
dBm  
Table 4 RF Receive characteristics  
9
AFC section  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
For 1Mbps and 1 MHz channel  
width, AFC_SETTLING=4.  
AFC range  
AFC accuracy  
± 500  
5
kHz  
kHz  
Measured using an unmodulated  
carrier.  
Table 5 AFC characteristics  
SWRS042A  
Page 10 of 83  
CC2400  
10 RSSI / Carrier Sense section  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
For 1Mbps and 1 MHz channel  
width.  
RSSI range / Carrier sense range  
80  
dB  
(The range is from –100 dBm to  
–20 dBm typically)  
RSSI settling time  
RSSI accuracy  
20  
± 4  
s
dB  
See page 44 for details  
Table 6 RSSI / Carrier sense characteristics  
11 IF section  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
Intermediate frequency (IF)  
1
MHz  
Digital channel filter bandwidth  
125  
1000  
kHz  
The digital channel filter 6dB-  
bandwidth is programmable in  
steps: 125, 250, 500 and 1000  
kHz. See page 39 for details.  
Table 7 IF characteristics  
12 Frequency Synthesizer section  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
Crystal oscillator frequency  
16  
MHz  
See page 49 for details.  
Crystal frequency accuracy  
requirement  
20  
±ppm  
The total crystal frequency  
accuracy, i.e. initial tolerance plus  
aging and temperature  
dependency, will determine the  
frequency accuracy of the  
transmitted signal. 1 Mbps FSK,  
250 kHz deviation.  
Crystal operation  
Parallel  
16  
C4 and C5 are loading  
capacitors, see page 49  
Crystal load capacitance  
Crystal ESR  
12  
20  
60  
pF  
16 pF recommended  
Crystal oscillator start-up time  
1.13  
ms  
16 pF load  
Note: This time can be reduced to  
15 s by enabling the XOSC core  
in power-down using the  
MANAND register.  
Phase noise  
Unmodulated carrier  
-108  
-114  
-114  
dBc/Hz At ±1 MHz offset from carrier  
dBc/Hz At ±2 MHz offset from carrier  
dBc/Hz At ±5 MHz offset from carrier  
PLL loop bandwidth  
50  
kHz  
SWRS042A  
Page 11 of 83  
CC2400  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
PLL lock time (RX / TX turn-on  
time)  
40  
Until within ± 10 kHz  
µs  
Step size is 1MHz, no calibration.  
Note: Calibration should be  
performed for frequency changes  
> 8 MHz.  
PLL turn-on time from IDLE mode,  
crystal oscillator on  
100  
Crystal oscillator running.  
Calibration time included.  
µs  
Table 8 Frequency synthesizer characteristics  
13 Digital Inputs/Outputs  
Parameter  
Min.  
Typ.  
Max.  
Unit Condition / Note  
Signal levels are referred to the  
voltage level at the pin DVDD3.3.  
Logic "0" input voltage  
Logic "1" input voltage  
0
0.3*  
V
V
DVDD  
0.7*  
DVDD  
DVDD  
Logic "0" output voltage  
Logic "1" output voltage  
Logic "0" input current  
Logic "1" input current  
DIO setup time  
0
0.4  
DVDD  
1  
V
V
Output current 8 mA,  
3.3 V supply voltage  
Output current 8 mA,  
3.3 V supply voltage  
Input signal equals GND  
2.5  
NA  
NA  
20  
µA  
µA  
ns  
1
Input signal equals DVDD  
TX un-buffered mode, minimum  
time DIO must be ready before  
the positive edge of DCLK  
TX un-buffered mode, minimum  
time DIO must be held after the  
positive edge of DCLK  
DIO hold time  
10  
ns  
Serial interface (SCLK, SI, SO and  
CSn) timing specification  
See Table 12 page 22  
Table 9 Digital input/output characteristics  
SWRS042A  
Page 12 of 83  
CC2400  
14 Pin Assignment  
1
36  
35  
34  
33  
32  
VCO_GUARD  
NC  
2
AVDD_VCO  
GIO6  
SO  
3
AVDD_PRE  
4
SI  
AVDD_RF1  
SCLK  
5
GND  
RF_P  
6
31  
CSn  
CC2400  
7
30 DCLK/FIFO  
TXRX_SWITCH  
RF_N  
8
29  
28  
27  
26  
25  
DIO/PKT  
TX  
GND  
9
AVDD_SW  
NC  
10  
11  
12  
RX  
DVDD1.8  
DVDD3.3  
NC  
AGND  
Exposed die  
attach pad  
Figure 1 CC2400 Top View  
Pin no.  
Pin name  
AGND  
Pin type  
Ground (analog)  
Description  
-
Exposed die attach pad. Must be connected to solid ground  
plane  
1
2
3
4
5
6
VCO_GUARD  
AVDD_VCO  
AVDD_PRE  
AVDD_RF1  
GND  
Power (Analog) Connection of guard ring for VCO shielding  
Power (Analog) Power supply for VCO  
Power (Analog) Power supply for Prescaler  
Power (Analog) Power supply for RF front-end  
Ground (Analog) Grounded pin for RF shielding  
RF_P  
RF I/O  
Positive RF input/output signal to LNA/from PA in  
receive/transmit mode  
7
8
TXRX_SWITCH  
RF_N  
Power (Analog) Common supply connection for RF front-end. Must be  
connected to RF_P and RF_N externally through a DC path.  
RF I/O  
Negative RF input/output signal to LNA/from PA in  
receive/transmit mode  
9
10  
GND  
AVDD_SW  
Ground (Analog) Grounded pin for RF shielding  
Power (Analog) Power supply connection  
SWRS042A  
Page 13 of 83  
CC2400  
Pin no.  
11  
12  
Pin name  
Pin type  
Description  
NC  
NC  
NC  
---  
---  
---  
No Connect  
No Connect  
No Connect  
13  
14  
15  
16  
17  
18  
19  
20  
AVDD_RF2  
AVDD_IF2  
AVDD_ADC  
DVDD_ADC  
DGND_GUARD  
DGUARD  
Power (Analog) Power supply for receive and transmit mixers  
Power (Analog) Power supply for transmit IF chain  
Power (Analog) Power supply connection of ADCs and DACs  
Power (Digital)  
Power supply for digital part of receive ADCs  
Ground (Digital) Ground connection for digital noise isolation  
Power (Digital)  
Digital Input  
Power supply connection for digital noise isolation  
BT/GR  
Selection of Built-in-Test or Generic Radio (normal operation).  
Connect to ground for normal operation (NOTE: For Chipcon  
internal use only.)  
21  
GIO1  
Digital I/O  
General digital I/O pin. Configure as output when not used.  
See Table 18  
22  
23  
24  
25  
26  
27  
28  
29  
DGND  
Ground (Digital) Ground connection for digital modules  
Ground (Digital) Substrate connection for digital I/O’s  
Ground (Digital) Substrate connection for digital modules  
DSUB_PADS  
DSUB_CORE  
DVDD3.3  
DVDD1.8  
RX  
Power (Digital)  
Power (Digital)  
Digital Input  
Digital I/O  
Power supply for digital I/O’s  
Power supply for digital modules  
Strobe signal for RX mode. Connect to ground when not used.  
Strobe signal for TX mode. Connect to ground when not used.  
TX  
DIO/PKT  
Digital I/O  
Data input/output in un-buffered mode or packet handling  
control signal. Configure as output when not used.  
30  
DCLK/FIFO  
Digital Output  
Data clock output signal in un-buffered mode or FIFO control  
signal. Leave open when not used.  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
CSn  
SCLK  
SI  
SO  
GIO6  
NC  
NC  
NC  
Digital Input  
Digital Input  
Digital Input  
Digital Output  
SPI: Chip Select  
SPI: Serial data clock  
SPI: Slave Input  
SPI: Slave Output  
General digital output pin. See Table 18  
No Connect  
No Connect  
No Connect  
No Connect  
No Connect  
Digital Output  
---  
---  
---  
---  
---  
NC  
NC  
AVDD_XOSC  
XOSC16_Q2  
XOSC16_Q1  
AVDD_IF1  
R_BIAS  
ATEST2  
Power (Analog) Power supply for 16 MHz crystal oscillator  
Analog output  
Analog input  
Power (Analog) Power supply connection of receive IF chain  
Analog Output  
Analog I/O  
16 MHz crystal oscillator  
16 MHz crystal oscillator or external clock input  
Connection for external precision bias resistor  
Analog test I/O for prototype and production testing. Leave not  
connected when not used.  
47  
48  
ATEST1  
Analog I/O  
Analog test I/O for prototype and production testing. Leave not  
connected when not used.  
AVDD_CHP  
Power (Analog) Power supply for phase detector and charge pump  
NOTES:  
The exposed die attach pad must be connected to a solid ground plane as this is the main ground connection for the  
chip.  
The digital inputs SCLK, SI and CSn are high-impedance inputs (no internal pull-up) and should have external pull-  
ups if not driven. RX and TX should have external pull-down if not driven (to prevent the state machine from being  
trigged). SO is high-impedance when CSn is high. External pull-up should be used at SO to prevent floating input at  
the microcontroller.  
SWRS042A  
Page 14 of 83  
CC2400  
15 Circuit Description  
DIGITAL  
ADC  
ADC  
DEMODULATOR  
- Digital RSSI  
LNA  
- Gain Control  
- Image Suppression  
- Channel Filtering  
- Demodulation  
AGC CONTROL  
TX/RX CONTROL  
DIGITAL  
INTERFACE /  
FIFO  
FREQ  
0
SmartRF  
SYNTH  
90  
CC2400  
TX POWER CONTROL  
DAC  
DIGITAL  
MODULATOR  
Power  
Control  
- Data Filtering  
- Modulation  
PA  
Σ
- Power Control  
XOSC  
On-chip  
DAC  
BIAS  
16 MHz  
Figure 2. CC2400 simplified block diagram  
programmable carrier sense indicator with  
output on either GIO1 or GIO6.  
A simplified block diagram of CC2400 is  
shown in Figure 2.  
In transmit mode the baseband signal is  
directly up-converted quadrature (I and Q)  
and then fed to the power amplifier (PA).  
CC2400 features a low-IF receiver. The  
received RF signal is amplified by the low-  
noise amplifier (LNA) and down-converted  
in quadrature (I and Q) to the intermediate  
frequency (IF). At IF (1 MHz), the I/Q  
signal is filtered and amplified, and then  
digitized by the ADCs. Automatic gain  
The TX IF signal is frequency shift keyed  
(FSK). Optionally Gaussian filtering can be  
used enabling GFSK. The BT of the  
Gaussian filter is 0.5 for a datarate of  
1 Mbps.  
control,  
final  
channel  
filtering,  
demodulation and bit synchronization is  
performed digitally.  
The internal T/R switch circuitry simplifies  
the antenna interface and matching. The  
antenna connection is differential. The  
biasing of the PA and LNA is done by  
connecting TXRX_SWITCH to RF_P and  
RF_N through an external DC path.  
CC2400 outputs (in un-buffered mode only)  
the digital demodulated data on the DIO  
pin. A synchronized data clock is then  
available at the DCLK pin. In buffered  
mode the demodulated data is sent to a  
FIFO and is accessible through the SPI  
interface. RSSI is available in digital  
format and can be read via the serial  
The frequency synthesizer includes a  
completely on-chip LC VCO and a 90  
degrees phase splitter for generating the  
interface. The RSSI also features  
a
SWRS042A  
Page 15 of 83  
CC2400  
LO_I and LO_Q signals to the down-  
conversion mixers in receive mode and  
up-conversion mixers in transmit mode.  
The VCO operates in the frequency range  
4800 – 4966 MHz, and the frequency is  
divided by two when split in I and Q.  
synthesizer. A PLL lock signal is available  
via the GIO pins.  
The digital baseband includes support for  
packet handling and data buffering.  
The 4-wire SPI serial interface is used for  
configuration (and data interface in  
buffered mode). A few digital I/O lines can  
be configured for use with packet handling  
strobe and interrupt signals.  
A
crystal must be connected to  
XOSC16_Q1 and XOSC16_Q2 and  
generates the reference frequency for the  
SWRS042A  
Page 16 of 83  
CC2400  
16 Application Circuit  
Few external components are required for  
the operation of CC2400.  
A
typical  
16.3 Crystal  
application circuit is shown in Figure 3. A  
description of the external components  
referring to Figure 3 are described in  
Table 10. The bill of materials (BOM) is  
given in Table 11.  
An external crystal with input and output  
loading capacitors (C421 and C431) is  
used for the crystal oscillator. See page 49  
for details.  
16.4 Digital I/O  
Good PCB layout is vital for proper  
operation, please see the section on PCB  
Layout Recommendations on page 56 for  
more details.  
The supply voltage for the digital I/O must  
match the interfacing microcontroller. The  
digital I/Os of CC2400 can interface  
microcontrollers with supply voltages in  
the range 1.6 – 3.6 V.  
16.1 Input / output matching  
The RF input/output is high impedance  
and differential. The optimum differential  
load for the RF port is listed on page 8.  
16.5 Power supply decoupling and  
filtering  
Proper power supply decoupling must be  
used for optimum performance. The  
placement and size of the decoupling  
capacitors and the power supply filtering  
are very important to achieve the best  
performance in an application. Chipcon  
provides a compact reference design that  
should be followed very closely.  
When using an unbalanced antenna like a  
monopole, a balun should be used in  
order to get optimum performance. The  
balun can be implemented using low-cost  
discrete inductors and capacitors. The  
balun consists of C61, C62, C71, C81,  
L61, L62 and L72, and will match the RF  
input/output to 50 , see Figure 3. L61  
and L62 also provide DC biasing of the  
LNA/PA input/output. L71 is used to  
isolate the TXRX_SWITCH pin. An  
internal T/R switch circuit is used to switch  
between the LNA and the PA. See  
“Input/output matching” on page 50 for  
more details.  
16.6 Power supply switching  
As described in a note in the Absolute  
Maximum Ratings section, the voltage  
supply to the chip core should not be  
switched off separately from the I/O supply  
voltage.  
If it is necessary to switch the core power  
supply off, for instance to save the power  
dissipated in the 1.8V regulator, the I/O  
supply should be turned off as well. This  
can be done quite easily by running the  
I/O supply from a microcontroller I/O pin.  
Current drawn on the I/O supply is just a  
few milliamps, so an ordinary I/O pin  
should have no problems in sourcing this  
current. Power sequencing should be  
performed so that both supplies are turned  
on and off simultaneously.  
If a balanced antenna, like a folded dipole,  
is used, the balun can be omitted. If the  
antenna also provides a DC path from the  
TXRX_SWITCH pin to the RF pins,  
inductors are not needed for DC biasing.  
The L71 isolation inductor should still be  
used to avoid antenna reflections. Figure 4  
shows a typical application circuit with  
differential antenna. The dipole has a  
virtual ground point, hence bias is  
provided without degradation in antenna  
performance. Please note that  
a
differential antenna is generally larger than  
an equivalent single-ended antenna.  
16.2 Bias resistor  
The bias resistor R451 is used to set an  
accurate bias current for the chip.  
SWRS042A  
Page 17 of 83  
CC2400  
Ref  
Description  
C71  
C61  
C81  
C62  
C421  
C431  
L61  
Front-end bias decoupling and match, see page 50  
Discrete balun and match, see page 50  
Discrete balun and match, see page 50  
DC block to antenna and match  
16MHz crystal load capacitor, see page 49  
16MHz crystal load capacitor, see page 49  
DC bias and match, see page 50  
L62  
DC bias and match, see page 50  
L71  
L81  
R451  
XTAL  
RF blocking inductor, see page 50  
Discrete balun and match, see page 50  
Precision resistor for current reference generator  
16MHz crystal, see page 49  
Table 10. Overview and description of external components for an unbalanced antenna  
(balun implemented with low cost discrete components)  
AVDD=1.8V AVDD=1.8V  
C431  
XTAL  
C421  
R451  
AVDD=1.8V  
1
2
3
36  
35  
VCO_GUARD  
AVDD_VCO  
NC  
GIO6  
34  
AVDD_PRE  
AVDD_RF1  
GND  
SO  
SI  
Antenna  
(50 Ohm)  
SPI-bus  
4
5
33  
32  
31  
30  
29  
C61  
SCLK  
CSn  
6
L62  
RF_P  
C71  
CC2400  
7
8
9
TXRX_SWITCH  
RF_N  
DCLK/FIFO  
DIO/PKT  
TX  
L71  
Optional  
digital  
interface  
L61  
C62  
28  
27  
26  
25  
GND  
L81  
10  
11  
12  
C81  
AVDD_SW  
RX  
NC  
NC  
DVDD=1.8V  
DVDD1.8  
DVDD3.3  
DVDD Digital I/O  
=1.8 / 3.3V  
AVDD=1.8V  
DVDD=1.8V  
Figure 3 Typical application circuit with discrete balun for interfacing single-ended  
antenna  
SWRS042A  
Page 18 of 83  
CC2400  
AVDD=1.8V AVDD=1.8V  
R451  
C431  
C421  
XTAL  
AVDD=1.8V  
1
2
3
36  
35  
VCO_GUARD  
AVDD_VCO  
NC  
GIO6  
34  
AVDD_PRE  
AVDD_RF1  
GND  
SO  
SI  
SPI-bus  
4
5
33  
32  
31  
30  
29  
SCLK  
CSn  
6
RF_P  
Folded  
dipole  
antenna  
L71  
CC2400  
L61  
7
8
9
TXRX_SWITCH  
RF_N  
DCLK/FIFO  
DIO/PKT  
TX  
Optional  
digital  
interface  
28  
27  
26  
25  
GND  
10  
11  
12  
AVDD_SW  
RX  
NC  
NC  
DVDD=1.8V  
DVDD1.8  
DVDD3.3  
DVDD Digital I/O  
=1.8 / 3.3V  
AVDD=1.8V  
DVDD=1.8V  
Figure 4 Typical application circuit with differential antenna (folded dipole)  
Item  
Single ended output, discrete  
balun  
Differential antenna  
C62  
C61  
C81  
C71  
C421  
C431  
L61  
5.6 pF, +/- 0.25pF, NP0, 0402  
0.5 pF, +/- 0.25pF, NP0, 0402  
0.5 pF, +/- 0.25pF, NP0, 0402  
100 nF, 10%, X5R, 0402  
Not used  
Not used  
Not used  
100 nF, 10%, X5R, 0402  
18 pF, 5%, NP0, 0402  
18 pF, 5%, NP0, 0402  
27 nH, 5%, Monolithic/multilayer, 0402  
Not used  
18 pF, 5%, NP0, 0402  
18 pF, 5%, NP0, 0402  
7.5 nH, 5%, Monolithic/multilayer, 0402  
5.6 nH, 5%, Monolithic/multilayer, 0402  
27 nH, 5%, Monolithic/multilayer, 0402  
7.5 nH, 5%, Monolithic/multilayer, 0402  
43 k, 1%, 0402  
L62  
L71  
L81  
R451  
XTAL  
27 nH, 5%, Monolithic/multilayer, 0402  
Not used  
43 k, 1%, 0402  
16 MHz crystal, 16 pF load (CL)  
16 MHz crystal, 16 pF load (CL)  
NOTE: Decoupling components are not included.  
Table 11. Bill of materials for the application circuits  
SWRS042A  
Page 19 of 83  
CC2400  
17 Configuration Overview  
CC2400 can be configured to achieve  
Crystal oscillator power-up / power  
down  
Data rate and line coding (NRZ,  
8B/10B coding)  
Synthesizer lock indicator mode  
Digital RSSI  
FSK / GFSK modulation  
Data buffering  
Packet handling hardware support  
optimum  
performance  
for  
different  
applications. Through the programmable  
configuration registers the following key  
parameters can be programmed:  
Receive / transmit mode  
RF frequency  
RF output power  
FSK frequency deviation  
Power-down / power-up mode  
18 Configuration Software  
microcontroller for the configuration of  
Chipcon provides users of CC2400 with a  
software program, SmartRF® Studio  
(Windows interface) that generates all  
necessary CC2400 configuration data,  
based on the user's selections of various  
parameters. These hexadecimal numbers  
will then be the necessary input to the  
CC2400.  
Figure 5 shows the user interface of the  
CC2400 configuration software.  
Figure 5. SmartRF® Studio user interface  
SWRS042A  
Page 20 of 83  
CC2400  
19 4-wire Serial Configuration Interface  
The data word is loaded into the internal  
configuration register, when the last bit,  
D0, of the 16 data bits has been written.  
CC2400 is configured via a simple 4-wire  
SPI-compatible interface (SI, SO, SCLK  
and CSn) where CC2400 is the slave. This  
interface is also used as data interface in  
buffered mode (see page 27).  
The configuration data will be retained  
during a programmed power-down mode,  
but not when the power-supply is turned  
off. The registers can be programmed in  
any order.  
There are 44 16-bit configuration registers,  
9 Command Strobe Registers, and one  
register to access the FIFO. Each register  
has a 7-bit address. The FIFO (32 bytes)  
is 8 bits wide. A Read/Write bit indicates a  
read or a write operation and forms the 8-  
bit address field together with the 7-bit  
address.  
The configuration registers can also be  
read by the microcontroller via the same  
configuration interface. The R/W bit must  
be set high to initiate the data read-back,  
then the seven address bits are sent.  
CC2400 then returns the data from the  
addressed register. SO is used as the  
data output and must be configured as an  
input by the microcontroller.  
Some registers are termed Command  
Strobe Registers. By addressing  
a
Command  
Strobe  
register  
internal  
sequences will be started. These  
commands can be used to quickly change  
from RX mode to TX mode, for example.  
The command strobe register is accessed  
in the same way as for a write operation,  
but no data is transferred. That is, only the  
R/W bit and the seven address bits are  
written before CSn should be set high.  
A full configuration of CC2400 requires  
sending 44 data frames of 24 bits each (7  
address bits, R/W bit and 16 data bits).  
The time needed for a full configuration  
depend on the SCLK frequency. With a  
SCLK frequency of 20 MHz the full  
configuration is done in less than 5 µs.  
Setting the device in power down mode  
requires addressing one command strobe  
register only, and will in this case take less  
than 0.4 µs. All registers except the strobe  
registers are also readable.  
Figure 7 shows a summary of read and  
write operations. A register read/write can  
be terminated after one byte if only the  
most significant byte is required. A register  
can also be accessed repeatedly without  
writing the address again. The buffer FIFO  
(8 bit wide, 32 bytes) can be written  
continuously by simply writing new bytes  
over and over. The internal data pointer is  
then updated for every written byte. The  
session is terminated when the CSn is set  
high.  
In each write-cycle, 24 bits are sent on the  
SI-line. The bit to be sent first is the R/W  
bit (0 for write, 1 for read). The next seven  
bits are the address-bits (A6:0). A6 is the  
MSB (Most Significant Bit) of the address  
and is sent first. The 16 data-bits are then  
transferred (D15:0). During address and  
data transfer the CSn (Chip Select, active  
low) must be kept low. See Figure 6.  
Please note that a longer hold time, tps, is  
needed before setting CSn high when  
accessing the FIFO in buffered mode.  
During the transfer of the address, the  
CC2400 returns a status byte on the SO  
line containing some important flags. This  
is shown in Table 13.  
The timing for the programming is shown  
in Figure 6 with reference to Table 12. The  
clocking of the data on SI into the CC2400  
is performed on the positive edge of  
SCLK.  
SWRS042A  
Page 21 of 83  
CC2400  
tps  
tns  
tsp  
tch  
tcl  
tsd  
thd  
SCLK:  
CSn:  
Write to register:  
A6  
S6  
A5  
S5  
A4  
S4  
A3  
A2  
S2  
A1  
S1  
A0  
S0  
X
DW15 DW14 DW13 DW12 DW11 DW10 DW  
9
DW  
8
X
DW  
7
DW  
6
DW  
5
DW  
4
DW  
3
DW  
2
DW  
1
DW  
0
X
0
SI  
S7  
S3  
X
SO  
Read from register:  
A6  
S6  
A5  
S5  
A4  
S4  
A3  
S3  
A2  
S2  
A1  
S1  
A0  
S0  
X
1
SI  
S7  
DR15  
DR14 DR13 DR12 DR11 DR10 DR  
9
DR  
8
DR  
7
DR  
6
DR  
5
DR  
4
DR3  
DR2  
DR1  
DR0  
DR15  
SO  
Figure 6. SPI timing diagram  
CSn:  
ADDR  
Command strobe:  
ADDR  
ADDR  
ADDR  
DATA8MSB DATA8LSB  
DATA8MSB  
Read or write a whole register (16 bit):  
Read or write 8 MSB of a register:  
Read or write a whole register continuously:  
Read or write n bytes from/to RF FIFO:  
DATA8MSB DATA8LSB DATA8MSB DATA8LSB  
... DATA8MSB DATA8LSB  
... DATAbyte n-2 DATAbyte n-1  
ADDRFIFO DATAbyte0 DATAbyte1 DATAbyte2 DATAbyte3  
Figure 7. Configuration registers write and read operations via SPI  
Parameter Symbol  
Min  
Max  
Units  
Conditions  
SCLK, clock  
frequency  
SCLK low  
pulse  
fSCLK  
tcl,min  
20  
MHz  
ns  
25  
25  
The minimum time SCLK must be low.  
The minimum time SCLK must be high.  
duration  
SCLK high  
pulse  
tch,min  
ns  
duration  
CSn setup  
time  
CSn hold  
time 1  
CSn hold  
time 2  
tsp  
tns  
tps  
25  
25  
ns  
ns  
ns  
The minimum time CSn must be low before  
positive edge of SCLK.  
The minimum time CSn must be held low after the  
last negative edge of SCLK.  
In buffered mode: The minimum time CSn must be  
held low after the last positive edge of SCLK. This  
only applies to FIFO accesses.  
300  
SI setup time  
SI hold time  
Rise time  
tsd  
thd  
25  
25  
ns  
ns  
ns  
ns  
The minimum time data on SI must be ready  
before the positive edge of SCLK.  
The minimum time data must be held at SI, after  
the positive edge of SCLK.  
The maximum rise time for SCLK and CSN  
trise  
tfall  
100  
100  
Fall time  
The maximum fall time for SCLK and CSn  
Note: The set-up- and hold-times refer to 50% of VDD.  
Table 12. SPI timing specification  
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CC2400  
Bit # Name  
Description  
7
6
5
4
-
Reserved, ignore value  
XOSC16M_STABLE  
RESERVED  
Indicates whether the 16 MHz oscillator is running ('1') or not  
Reserved  
SYNC_RECEIVED  
Indicates whether a sync word has been received or not so far in  
the RX operation  
3
CRC_OK  
Indicates whether the next two bytes in the FIFO will make the  
CRC calculation successful or not:  
0: CRC not OK or CRC off  
1: CRC OK  
2
FS_LOCK  
Indicates whether the frequency synthesiser is in lock ('1') or not.  
Reserved  
1:0  
RESERVED[1:0]  
Table 13. Status byte returned during address transfer  
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CC2400  
20 Overview of Configurations and Hardware Support  
Table 14 below gives a summary of the  
possibilities.  
The CC2400 can be configured for different  
data interfaces, coding schemes and  
packet handling hardware support.  
Data  
Data coding Packet handling support  
interface  
Buffered  
NRZ  
TX:  
Preamble generation  
(32 byte FIFO  
accessed  
through the  
SPI interface)  
Sync word insertion  
CRC computation and insertion  
RX:  
Sync Word detection  
CRC computation and check  
8/10 code  
Manchester  
Un-buffered  
NRZ  
RX:  
Sync Word detection  
(DIO and  
DCLK  
synchronous  
interface)  
Manchester  
Table 14. Configurations and hardware support  
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CC2400  
21 Microcontroller Interface and Pin Configuration  
Used in a typical system, CC2400 will  
interface to  
a
microcontroller. This  
21.2 Signal interface in un-buffered  
microcontroller must be able to:  
mode  
A bi-directional pin (DIO) is used for data  
to be transmitted and received. DCLK  
providing the data timing should be  
connected to a microcontroller input.  
Program CC2400 into different modes  
and read back status information via  
the 4-wire SPI-bus configuration  
interface (SI, SO, SCLK and CSn). In  
buffered mode the data signal is also  
transmitted through the SPI-bus  
The data is clocked in/out at the positive  
edge of DCLK.  
Interface  
to  
the  
bi-directional  
21.3 General control and status pins  
Optionally, in buffered mode, the FIFO pin  
synchronous data signal interface (DIO  
and DCLK) if un-buffered data  
transmission is to be used  
Optionally interface to the general  
control and status pins (RX, TX, FIFO,  
PKT, GIO1 and GIO6) if the hardware  
supported packet handling functions  
are to be used  
can  
be  
used  
to  
interrupt  
the  
microcontroller at full/empty FIFO. This pin  
should then be connected to  
microcontroller interrupt pin.  
a
Optionally, using the packet handling  
support, the PKT pin can be used in  
Optionally the microcontroller can  
monitor the general I/O pins (GIO1,  
GIO6) for frequency lock status, carrier  
buffered  
mode  
to  
interrupt  
the  
microcontroller when a sync word is  
detected (RX mode) and packet is  
transmitted (TX mode). This pin should  
then be connected to a microcontroller  
interrupt pin.  
sense  
status,  
or  
other  
status  
information  
Optionally, the microcontroller can read  
back digital RSSI value and other  
status information via the 4-wire SPI  
interface  
The polarity of FIFO and PKT can be  
controlled by the INT register (address  
0x23).  
21.1 Configuration interface  
The microcontroller interface is shown in  
Figure 8. The microcontroller uses a  
minimum of 4 I/O pins for the SPI  
configuration interface (SI, SO, SCLK and  
CSn). All other pins are optional. SO  
should be connected to an input at the  
microcontroller. SI, SCLK and CSn must  
be microcontroller outputs.  
Optionally, the RX and TX pins can be  
used to change the operating mode of  
CC2400 as an alternative to using the SPI  
interface strobe commands. These pins  
should  
then  
be  
connected  
to  
microcontroller output pins. If the RX and  
TX pins are not used, they should be  
grounded in order to prevent accidental  
change of mode.  
The microcontroller pins connected to SI,  
SO and SCLK can be shared with other  
Optionally, the GIO1 and GIO6 can be  
used to monitor several status signals as  
selected by the IOCFGregister. The GIO6  
SPI-interface devices. SO is  
a high  
impedance output as long as CSn is not  
activated (active low).  
pin  
should  
be  
connected  
to  
a
microcontroller input pin. See Table 18 for  
available signals.  
CSn should have an external pull-up  
resistor or be set to a high level during  
power down mode in order to prevent the  
input from floating. SI and SCLK should be  
set to a defined level to prevent the input  
from floating.  
Table 15 gives a summary of the possible  
pin configurations in the different operation  
modes.  
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Page 25 of 83  
CC2400  
Pin name  
SCLK  
SI  
SO  
CSn  
DIO/  
PKT  
29  
I/O  
-
DCLK/ RX  
FIFO  
TX  
GIO1*  
GIO6*  
Pin number  
Direction  
Buffered  
mode  
32  
I
SCLK  
33  
I
SI  
34  
O
SO  
31  
I
CSn  
30  
27  
I
28  
I
(TX)  
21  
O
(GIO1)  
35  
O
(GIO6)  
O
FIFO  
(RX)  
SCLK  
SI  
SO  
CSn  
PKT  
FIFO  
(RX)  
(TX)  
(GIO1)  
(GIO6)  
Buffered  
mode with  
Packet  
handling  
Un-buffered  
mode  
SCLK  
SI  
SO  
CSn  
DIO  
DCLK  
(RX)  
(TX)  
(GIO1)  
(GIO6)  
NOTE: Pin functions in parentheses are optional  
* The use of GIO1 and GIO6 are selected in register IOCFG(address 0x08)  
Table 15. Pin configuration  
Buffered RF Mode:  
CC2400  
Unbuffered RF Mode:  
CC2400  
µC  
µC  
Data &  
Control  
Control  
CSn  
SI  
SO  
GIO1  
MOSI  
MISO  
SCLK  
CSn  
SI  
SO  
GIO1  
MOSI  
MISO  
SCLK  
SCLK  
SCLK  
DIO/PKT  
DCLK/FIFO  
Other Circuit  
Data  
CSn  
SI  
GIO2  
SO  
SCLK  
Full hardware support for packet handling :  
Data &  
CC2400  
µC  
Control  
CSn  
SI  
SO  
GIO1  
MOSI  
MISO  
SCLK  
SCLK  
DIO/PKT  
DCLK/FIFO  
RX  
GIO2  
GIO3  
GIO4  
GIO5  
GIO6  
GIO7  
TX  
GIO1  
GIO6  
Control  
Figure 8. Microcontroller interface  
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CC2400  
22 Data Buffering  
mode. The threshold (FIFO_THRESHOLD)  
is set in INT.FIFO_THRESHOLD[4:0].  
The CC2400 can be used with a buffered or  
un-buffered data interface. The data  
buffering mode is controlled by the  
GRMDM.PIN_MODE[1:0] bits (register  
address 0x20).  
In receive mode there will be an interrupt  
when the number of received bytes in the  
FIFO reaches FIFO_THRESHOLD. The  
default value is 30, giving an interrupt  
when 30 bytes are received. If the FIFO  
becomes full (32 bytes) before it is read,  
the reception will be terminated (goes to  
the FS_ON state).  
In un-buffered mode a synchronous data  
clock is provided by CC2400 at the DCLK  
pin, and the DIO pin is used as data  
input/output (see Figure 8).  
22.1 Buffered mode  
In transmit mode there will be an interrupt  
when the number of bytes left in the FIFO  
reaches 32 - FIFO_THRESHOLD. For the  
default value this will happen when there  
are 2 bytes left. The transmission is  
terminated when the FIFO runs empty  
(goes to the FS_ON state). Note that in  
order for the FIFO pin to give an interrupt  
in transmit mode the number of bytes  
must first exceed 32 - FIFO_THRESHOLD.  
In the buffered mode a 32-byte First-in  
First-Out (FIFO) register block is used for  
data to be transmitted and data received.  
The FIFO is accessed through the  
FIFOREG register (address 0x70) using  
the SPI interface. Multiple bytes can be  
written to the FIFO without repeating the  
address if the CSn line is held low.  
The crystal oscillator must be running  
when accessing the FIFO.  
The FIFO pin activity is illustrated in  
Figure 10.  
By using the FIFO buffer the data can be  
transmitted in bursts. The buffered mode  
will therefore offload the host controller  
keeping the SPI data rate much lower than  
the data rate on the air. This gives also a  
great advantage in reducing the current  
consumption as the transmitter and  
receiver are enabled only in short periods.  
It also allows the SPI to operate faster  
than the data rate, providing more time for  
the MCU to work between data transfers.  
The INT.FIFO_POLARITY bit sets the  
polarity of the interrupt signal.  
In TX mode, the FIFO pin goes low when  
a transmission starts and the preamble is  
sent. It will stay low as long as the FIFO is  
empty. When data is written to the FIFO, it  
will go high. If the number of bytes in the  
FIFO goes below the FIFO_THRESHOLD,  
the FIFO pin will go low again. If the FIFO  
pin goes low, it will stay low until the CRC  
has been transmitted.  
More than 32 bytes can be received if the  
FIFO is read during reception. In the same  
way more than 32 bytes can be  
transmitted if new data is written into the  
FIFO during transmission. Figure 9 shows  
the ways the FIFO can be used during  
transmission.  
FIFO_FULL and FIFO_EMPTY signals are  
available on the general-purpose I/O pins.  
These two signals are affected by  
FIFO_THRESHOLD.  
In transmit mode, FIFO_EMPTY is low if  
the number of bytes in the FIFO is more  
than 32-FIFO_THRESHOLD. In receive  
mode, FIFO_EMPTY goes low when there  
is more than 1 byte in the FIFO.  
22.2 Buffered mode hardware support  
In the buffered mode the FIFO pin can be  
used as an interrupt output to assist the  
microcontroller in supervising the FIFO.  
The FIFO pin can be programmed to give  
an interrupt when the FIFO is nearly  
empty in TX mode, and nearly full in RX  
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Page 27 of 83  
CC2400  
FIFO_FULL is high if the number of bytes  
in the FIFO is greater or equal to  
FIFO_THRESHOLD.  
FIFO  
Data to  
packet  
engine  
Data  
f rom  
MCU  
a) Single packet in FIFO  
FIFO  
Data  
Data already sent  
to packet engine  
pending  
f rom MCU  
b) Packet longer than FIFO  
Figure 9. Ways in which the FIFO can be used during transmit mode  
RF data  
Preamble  
Sync word  
Data  
PKT  
RX mode:  
FIFO  
MCU data  
TX mode:  
PKT  
FIFO  
Figure 10. FIFO and PKT timing diagram  
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CC2400  
23 Packet Handling Hardware Support  
is required, Chipcon recommends that  
FSK be used at 1 Mbps instead of GFSK.  
The CC2400 has built-in hardware support  
for packet oriented radio protocols.  
Number of bytes  
The buffered mode packet handling  
support can in transmit mode be used to  
construct the data packet:  
GRMDM.  
(8 bits)  
PRE_BYTES[2:0]  
000  
001  
010  
011  
100  
101  
110  
111  
0*  
1
Add a programmable number of  
preamble bytes  
2
4
Add a synchronization word  
8
Compute and add  
a
CRC  
16  
32  
computed over the data field  
Infinitely until TX  
In receive mode the packet handling  
support can be used to de-construct the  
data packet:  
GRMDM.PRE_BYTES  
[2:0]is set to 000  
* Should not be used if packet reception is to be  
used. Use to terminate infinite transmission (111).  
Synchronization word detection  
Compute and check the received  
CRC  
The length of the synchronization word is  
programmable as shown below.  
The packet handling support can be  
combined with the 8/10 line-encoding  
scheme. The 8/10 coding will apply to the  
data field (FIFO data) of the packet only  
(and CRC).  
Number of bits  
GRMDM.  
SYNC_WORD_SIZE  
[1:0]  
00  
01  
10  
11  
8
16  
24  
32  
In un-buffered mode the synchronization  
word detection can be used to mute DCLK  
until a valid sync word is received.  
The  
synchronization  
word  
is  
programmable in the SYNCL and SYNCH  
registers. The default (and recommended)  
synchronization word length is 32 bits,  
which gives high immunity against false  
synchronization word indication. If lower  
immunity can be accepted, one can  
reduce the length to 16 bits. (However,  
using 8 bits will typically give too many  
false synchronization word indications.)  
23.1 Data packet format  
The format of the data packet can be  
configured, and can consist of the  
following items:  
Preamble  
Synchronization word  
Data  
CRC  
A threshold on the number of bits in error  
when receiving the synchronization word  
See Table 16 and Figure 11 for details.  
can  
be  
programmed  
in  
The preamble pattern is ‘(0)101010…’.  
The first bit in the preamble is always the  
same as the first bit in the synchronization  
word. The length of the preamble is  
GRMDM.SYNC_ERRBITS_ALLOWED[1:0]  
in the range 0 – 3. (A threshold of 0 is  
default.)  
programmable.  
The  
default  
and  
23.2 Error detection  
recommended length is 4 bytes.  
When the CRC is enabled it will be  
calculated based on the data field of the  
packet, i.e. not including the preamble or  
When using GFSK modulation at 1 Mbps,  
Chipcon recommends using a preamble  
length of 32 bytes in order to avoid a high  
level of bit errors. If low packet overhead  
the  
synchronization  
word.  
When  
transmitting the packet the CRC is  
appended after the last data byte in the  
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Page 29 of 83  
CC2400  
data field, i.e. when the FIFO becomes  
empty.  
If the reception of the packet is error free,  
the PKTSTATUS.CRC_OK flag is set (also  
available on the GIO1 and GIO6 pins).  
When a packet is being received the CRC  
is calculated as the data is read out of the  
FIFO. When all data is read, the next two  
bytes in the FIFO are the CRC.  
The CRC polynomial is:  
x16 + x15 + x2 + 1  
Packet field  
Use  
Length  
Preamble  
Mandatory  
1 byte  
Synchronisation word  
Mandatory  
Data field  
Mandatory  
1 byte  
CRC  
Optional  
2 bytes  
1, 2, 3 or 4 bytes  
GRMDMregister  
configuration bits  
PRE_BYTES[2:0]  
SYNC_WORD_SIZE[1:0]  
CRC_ON  
Table 16. Data packet format  
Optional 8/10 coding  
Legend:  
Optional CRC-16 calculation  
Inserted automatically in TX,  
processed and remov ed in RX.  
Unprocessed user data  
Preamble bits  
(1010...1010)  
Data field  
32 bits  
16/32 bits  
8 x n bits  
16 bits  
Figure 11. Packet format details (with recommended lengths of preamble and  
synchronization word)  
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CC2400  
Outside of the TX and RX modes, the PKT  
pin provides an indication of whether the  
PLL is in lock or not. For example, in the  
FSON state, the PKT pin will be high if the  
PLL is in lock.  
23.3 Hardware interface  
In the buffered mode the PKT pin can be  
used as an interrupt output to assist the  
microcontroller  
in  
supervising  
the  
transmission and reception of data  
packets.  
The PKT pin activity is illustrated in Figure  
10.  
The PKT pin can be programmed to give  
an interrupt when the synthesizer has  
locked and is ready to receive / transmit a  
data packet. Receive mode or transmit  
mode can then be activated.  
The polarity of the interrupt signal is set by  
the INT.PKT_POLARITYbit.  
In transmit mode, the PKT pin will go low  
for a short while when the transmission is  
completely over (the CRC has been sent).  
In receive mode there will be an interrupt  
when the synchronization word is found.  
Incoming data will then be written to the  
FIFO.  
In receive mode, the PKT pin will go low  
when a sync word is found. It will stay low  
for the period of time it would take to  
receive 32 bytes, no matter how long the  
received packet is (the CC2400 does not  
know how long incoming packets are).  
In transmit mode there will be an interrupt  
when the FIFO has run empty, the two  
CRC bytes have been transmitted and the  
transmitter has been turned off.  
24 Data / Line Encoding  
The CC2400 can operate with the following  
8/10 coding means that 8 bits are coded  
into 10 chips using the original IBM  
8B/10B-coding scheme. The effective bit  
rate is 80 % of the baud rate using 8/10  
coding and is therefore more efficient that  
the Manchester coding.  
line-encoding formats:  
NRZ (Non-Return-to-Zero)  
Manchester coding (also known  
as bi-phase-level)  
8/10 coding  
The data format is controlled by the  
GRMDM.DATA_FORMAT[1:0] bits.  
Manchester coding and 8/10 coding  
reduce the effective bit rate but are in  
some applications used for spectral  
properties and error detection.  
The benefit of the Manchester coding and  
8/10 coding is the whitening of the  
transmission spectrum even when rows of  
equal bits are to be transmitted, improved  
clock recovery properties and DC balance.  
Setting the MDMTST0.INVERT_DATA bit  
the data is inverted before transmission in  
TX mode and inverted after reception in  
RX mode.  
Manchester coding means coding each bit  
into two chips of opposite polarity. The  
Manchester code is based on transitions;  
a
“0” is encoded as  
a
low-to-high  
transition, a “1” is encoded as a high-to-  
low transition. See Figure 14. The  
Manchester code ensures that the signal  
has a constant DC component, which is  
necessary in some FSK demodulators.  
This is not required by the CC2400  
demodulator, but the coding option is  
included for compatibility reasons. The  
effective bit rate is half the baud rate using  
Manchester coding.  
24.1 Data encoding in buffered mode  
In the buffered mode, using the internal  
FIFO, all three line-encoding schemes can  
be used.  
The encoding/decoding takes place as the  
data is sent from the FIFO to the  
modulator, and from the demodulator to  
the FIFO. The line encoding is therefore  
invisible to the user.  
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CC2400  
into the interfacing circuit at the rising  
edge of DCLK. See Figure 12.  
If 8/10 coding is selected when using the  
packet mode support, it should be noted  
that the preamble and the sync words are  
not encoded.  
Synchronous Manchester encoded mode.  
In transmit mode CC2400 provides the data  
clock at DCLK, and DIO is used as data  
input. Data is clocked into CC2400 at the  
rising edge of DCLK and should be in NRZ  
format. The data is modulated at RF with  
Manchester code. The encoding is done  
by CC2400. In this mode the effective bit  
rate is half the baud rate due to the  
coding. This limits the maximum bit rate to  
500 kbps. In receive mode CC2400 does  
the synchronization and provides received  
data clock at DCLK and data at DIO.  
CC2400 does the decoding and NRZ data  
is presented at DIO. The data should be  
clocked into the interfacing circuit at the  
rising edge of DCLK. See Figure 13.  
24.2 Data encoding in un-buffered  
mode  
When data buffering is not used, but the  
DIO/DCLK interface, the CC2400 can be  
configured for two different data formats:  
Synchronous NRZ mode. In transmit  
mode CC2400 provides the data clock at  
DCLK, and DIO is used as data input.  
Data is clocked into CC2400 at the rising  
edge of DCLK. The data is modulated at  
RF without encoding. In receive mode  
CC2400 does the synchronization and  
provides received data clock at DCLK and  
data at DIO. The data should be clocked  
Transmitter side:  
DCLK  
Clock provided by  
CC2400  
DIO  
Data provided by microcontroller (NRZ)  
“RF”  
FSK modulating signal (NRZ),  
internal in CC2400  
Receiver side:  
“RF”  
Demodulated signal (NRZ),  
internal in CC2400  
DCLK  
DIO  
Clock provided by  
CC2400  
Data provided by CC2400 (NRZ)  
Figure 12. Synchronous NRZ mode  
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CC2400  
Transmitter side:  
Clock provided by  
CC2400  
DCLK  
DIO  
Data provided by microcontroller (NRZ)  
“RF”  
FSK modulating signal (Manchester encoded),  
internal in CC2400  
Receiver side:  
“RF”  
Demodulated signal (Manchester encoded),  
internal in CC2400  
DCLK  
DIO  
Clock provided by  
CC2400  
Data provided by CC2400 (NRZ)  
Figure 13. Synchronous Manchester encoded mode  
1 0 1 1 0 0 0 1 1 0 1  
TX  
data  
Time  
Figure 14. Manchester encoding  
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CC2400  
25 Radio control state machine  
command strobe registers, or by using the  
RX and TX control pins. It is possible to  
change quickly between TX and RX by  
way of the FS On state.  
CC2400 has a built-in state machine that is  
used to switch between different operation  
states (modes). The change of state is  
done either by writing to command strobe  
registers, or using dedicated pins.  
Turning off RF can be accomplished by  
either accessing the command strobe  
register SRFOFF or by using the RX and  
TX control pins. When using the RX and  
TX pins to go from the FS On to Radio Off  
it is important that TX is set to 0 before RX  
is set to 0.  
Before using the radio in either RX or TX  
mode, the main crystal oscillator must be  
turned on and become stable. The crystal  
oscillator has a start-up time given in  
Table 8, during which its output is gated  
internally to avoid timing problems  
stemming from too narrow clock pulses.  
The crystal oscillator is controlled by  
The state transitions using the RX and TX  
pins are illustrated in Figure 15.  
accessing  
command  
the  
SXOSCON/SXOSCOFF  
registers. The  
strobe  
Note that to switch between RX and TX,  
the FSDIV register must be updated. This  
is because direct conversion is used in TX  
mode, while an IF frequency of 1 MHz is  
used in RX mode. Please see page 47 for  
XOSC16M_STABLE bit in the status  
register returned during address transfer  
indicates whether the oscillator is running  
and stable or not (See Table 13). This  
status register can be polled when waiting  
for the oscillator to start.  
more  
information  
about  
frequency  
programming.  
The frequency synthesizer (FS) can be  
started by either accessing the command  
strobe register SFSON or by using the RX  
and TX control pins. The FS will then enter  
its self-calibration mode. After the  
calibration is performed, the FS needs to  
lock onto the right LO frequency. The  
calibration and lock acquisition time is  
given in Table 8.  
Also note that the FSDIV register should  
only be changed when the radio is in IDLE  
mode, otherwise the PLL can go out of  
lock.  
When the FS is in lock it is possible to go  
into RX or TX mode. That can be done  
either by accessing the SRX/STX  
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Page 34 of 83  
CC2400  
SXOSCOFF  
OFF  
[0]  
SXOSCON &  
Osc. settled  
IDLE  
[1]  
RX=TX=1  
SRX | STX | SFSON  
PIN  
STROBE  
RXTX_CAL  
[14]  
RXTX_CAL  
[8]  
All calib done &  
All calib done &  
fs in lock  
fs in lock  
PIN  
FS_ON  
[9]  
STROBE  
RX=TX=0 |  
RX=TX=1  
SFSON  
STX  
FS_ON  
TX=0  
SFSON | packet done  
[15]  
RX=0  
RX=TX=0 |  
RX=TX=1  
SRX  
RX=TX=0  
PIN  
PIN  
RX  
STROBE  
TX  
STROBE  
TX  
RX  
[12]  
[10]  
[17]  
[16]  
TX=0 |  
TX=1 |  
RX=0 | packet done  
SRFOFF|  
SFSON | packet  
done  
RX=1 | packet done  
PIN  
TX_OFF  
[13]  
PIN  
RX_OFF  
[11]  
STROBE  
TX_OFF  
[18]  
Immediately  
SRFOFF  
BEFORE_IDLE  
[24]  
Figure 15. Radio control state diagram (FSMSTATE.FSM_CUR_STATE[4:0] value in  
brackets)  
Figure 15 shows a state transition diagram  
for the radio control state machine. This  
figure shows the possibilities that exist for  
changing between states. Note for  
example that it is not possible to go from  
IDLE mode back to OFF. This diagram  
can be very useful for debugging what is  
happening within the CC2400 by reading  
FSMSTATE.FSM_CUR_STATE[4:0].  
CC2400 will get stuck in the  
STROBE_RXTX_CAL state. The chip  
must then be reset to exit this state. This  
should never happen in an actual  
application as long as recommended  
register settings are used.  
Also note that the frequency register  
FSDIVshould only be modified when the  
CC2400 is in IDLE mode, otherwise the  
PLL may go out of lock since calibration is  
only performed when exiting the IDLE  
state  
If invalid parameters are used during  
development or testing, the PLL may not  
lock after calibration. If this happens, the  
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Page 35 of 83  
CC2400  
26 Power Management Flow Chart  
with very low power consumption and the  
crystal oscillator is not running.  
CC2400 offers great flexibility for power  
management in order to meet strict power  
consumption requirements in battery-  
operated applications.  
Figure 17 shows the sequence for  
entering RX or TX mode. The flow chart  
illustrates the simplest way to send a data  
packet using the strobe command  
registers. After one or more data packets  
are transmitted or received, the chip is  
again set to Power Down mode.  
After reset the CC2400 is in Power Down  
mode. All configuration registers can then  
be programmed in order to make the chip  
ready to operate at the correct frequency,  
data rate and mode. Due to the very fast  
start-up time, the CC2400 can remain in  
Power Down until a transmission session  
is requested.  
During chip initialization a few registers  
need to be programmed to other values  
than their reset values. SmartRF® Studio  
should be used to find/generate the  
required configuration data for these  
registers.  
Figure 16 shows a typical power-on and  
initializing sequence. After this initializing  
sequence the chip is in Power Down mode  
Power off  
Supply power turned on  
Reset:  
MAIN = 0x0000  
MAIN = 0x8000  
Program all registers that are  
different from reset value  
Power Down  
Figure 16. Initializing sequence  
SWRS042A  
Page 36 of 83  
CC2400  
PD  
(Power Down)  
SXOSCON  
Wait for the specified crystal  
oscillator start-up time, or poll the  
XOSC16M_STABLE bit  
Wait until crystal oscillator is  
stable  
IDLE  
(XOSC is running)  
SFSON  
The PLL and filters are  
calibrated  
FSON  
(XOSC and PLL is running)  
RX: SRX  
TX  
RX or TX?  
Write data to FIFO  
TX: STX  
Data is received. FIFO should  
be read if buffered mode is  
used  
Data is transmitted. FIFO  
should be filled if buffered  
mode is used  
Go to  
Go to  
NO: SFSON  
YES: SXOSCOFF  
YES: SXOSCOFF  
NO: SFSON  
power  
power  
down?*  
down?*  
NO: SRFOFF  
NO: SRFOFF  
Power Down  
*Go to PD state if the crystal oscillator  
should be shut off in order to save  
power. Go back to IDLE if a new  
packet shall be received/transmitted  
quickly. Or go back to FSON if  
changing fast between RX and TX  
mode.  
Figure 17. Sequence for activating RX or TX mode  
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Page 37 of 83  
CC2400  
27 FSK Modulation Formats  
The data modulator can modulate 2FSK,  
which is two level FSK, and GFSK, which  
is a Gaussian filtered FSK with BT=0.5 at  
1 Mbps (for lower data rates BT will be  
higher).  
However, if GFSK modulation is used  
together with a data rate of 1 Mbps, it is  
recommended to use a preamble length of  
32 bytes as otherwise packet error  
performance can be affected.  
The purpose of the GFSK is to make a  
more bandwidth efficient system. The  
modulation and the Gaussian filtering is  
Figure 18 shows a plot of the spectrum for  
FSK and GFSK modulation. Input data  
was a PN9 sequence. The plot was  
captured using a spectrum analyzer set to  
5 MHz span and 300 kHz RBW.  
performed  
internally.  
The  
bit  
GRMDM.TX_GAUSSIAN_FILTER  
enables the GFSK.  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
FSK  
GFSK  
2,438  
2,439  
2,440  
2,441  
2,442  
2,443  
Frequency [GHz]  
Figure 18. Modulated spectrum  
28 Built-in Test Pattern Generator  
The CC2400 has a built-in test pattern  
The PN9 generator can be used for  
transmission of ‘real-life’ data when  
measuring modulation bandwidth or  
occupied bandwidth.  
generator that can generate  
a
PN9  
The  
pseudo  
random  
sequence.  
MDMTST0.TX_PRNG bit enables the PN9  
generator.  
The PN9 pseudo random sequence is  
defined by the polynomial x9 + x5 + 1.  
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Page 38 of 83  
CC2400  
29 Receiver Channel Bandwidth  
In order to meet different channel width  
and channel spacing requirements, the  
receiver’s digital channel filter bandwidth  
is programmable. It can be programmed  
from 125 to 1000 kHz.  
There is a tradeoff between selectivity and  
accepted  
frequency  
tolerance.  
In  
applications where larger frequency drift is  
expected (depends on the accuracy of the  
crystal), the filter bandwidth should be  
increased, at the expense of reduced  
adjacent channel rejection (ACR).  
The GRDEC.CHANNEL_DEC[1:0]register  
bits control the bandwidth.  
It is strongly recommended to use one of  
the three settings for over-the-air data  
rates and channel bandwidths as  
described in the section “Data Rate  
Programming” on page 40.  
The table below summarizes the  
selectable channel bandwidths.  
Channel filter  
bandwidth  
[kHz]  
GRDEC.CHANNEL_DEC[1:0]  
[binary]  
1000  
00  
01  
10  
11  
500  
250  
125  
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Page 39 of 83  
CC2400  
30 Data Rate Programming  
The supported over-the-air data rates are  
1Mbps, 250kbps and 10kbps. The data  
rate is programmable via the GRDEC  
register.  
BW  
[kHz]  
Data rate  
[kbps]  
CHANNEL  
_DEC  
[binary]  
00  
DEC_  
VAL  
[decimal]  
1000  
1000  
500  
0
3
49  
1000  
250  
10  
00  
Supported channel filter bandwidths and  
data rates are shown in the following  
table.  
01  
Figure 19 shows how sensitivity varies as  
a function of frequency offset between the  
transmitter and the receiver for various  
data rates. It is possible to tolerate even  
larger offsets by making use of the AFC  
feature; please see page 42 for further  
details.  
-10  
-30  
-50  
250 kbps  
1 Mbps  
10 kbps  
-70  
-90  
-110  
Offset (kHz)  
Figure 19. Sensitivity as a function of frequency offset  
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Page 40 of 83  
CC2400  
31 Demodulator, Bit Synchronizer and Data Decision  
The block diagram for the demodulator,  
data slicer and bit synchronizer is shown  
in Figure 20. The built-in bit synchronizer  
extracts the data rate and performs data  
decision. The data decision is done using  
over-sampling and digital filtering of the  
incoming signal. This improves the  
reliability of the data transmission and  
provides a synchronous clock in the un-  
buffered mode. Using the buffered mode  
simplifies the data interface further, as  
data can be written and read byte-for-byte  
in bursts from the FIFO.  
signal. Once a shift in the received  
frequency larger than half the expected  
separation is detected, a bit transition is  
recorded and the average value to be  
used by the data slicer is calculated.  
The actual number of samples used to find  
the averaging value can be programmed  
and set higher for better data decision  
accuracy. This is controlled by the  
AFC_SETTLING[1:0] bits. If RX data is  
present in the channel when the RX chain  
is turned on, then the data slicing estimate  
will usually give correct results after 4 bits.  
The data slicing accuracy will increase  
The suggested preamble is a 32 bit  
‘(0)10101…’ bit pattern, the same as used  
by the packet handling support, see page  
29. This is necessary for the bit  
synchronizer to synchronize with the  
coding correctly.  
after  
this,  
depending  
on  
the  
AFC_SETTLING[1:0] bits. If the start of  
a transmission occurs after the RX chain  
is turned on, the minimum number of bit  
transitions (or preamble bits) before  
correct data slicing will depend on the  
AFC_SETTLING[1:0] bits, as shown in  
Table 17. The recommended setting is  
11b, requiring 16 data bits of preamble to  
fill the averaging filter completely.  
The data slicer performs the bit decision.  
Ideally the two received FSK frequencies  
are placed symmetrically around the IF  
frequency. However, if there is some  
frequency error between the transmitter  
and the receiver, the bit decision level  
should be adjusted accordingly. In CC2400  
this is done automatically by measuring  
the two frequencies and by using the  
average value as the decision level.  
The internally calculated average FSK  
frequency value gives a measure for the  
frequency offset of the receiver compared  
to the transmitter. The frequency offset  
can  
be  
read  
from  
This  
RSSI.RX_FREQ_OFFSET[7:0].  
The digital data slicer in CC2400 uses an  
average value of the minimum and  
maximum frequency deviation detected as  
information can also be used for an  
automatic frequency control, as described  
at page 43.  
the  
comparison  
level.  
The  
MDMTST0.AFC_DELTA register is used to  
set the expected deviation of the incoming  
Average  
filter  
Bit  
Digital IF  
filtering  
Frequency  
detector  
Data  
filter  
Data slicer  
comparator  
synchronizer  
and data  
Decimator  
decoder  
Figure 20. Demodulator block diagram  
SWRS042A  
Page 41 of 83  
CC2400  
AFC settling time  
# Bits  
MDMTST0.AFC_SETTLING[1:0]  
00  
01  
10  
11  
2
4
8
16  
Table 17. Minimum number of bits for the averaging filter  
32 Automatic Frequency Control  
this feature please refer to page 53  
(Crystal drift compensation).  
CC2400 has a built-in optional feature  
called  
AFC  
(Automatic  
Frequency  
Control). This feature can be used to  
measure and compensate for frequency  
drift.  
Figure 21 shows how the value of the  
FREQEST.RX_FREQ_OFFSET[7:0]  
register varies as a function of frequency  
offset  
for  
different  
values  
of  
The average frequency offset of the  
received signal (from the nominal IF) can  
MDMTST0.AFC_SETTLING[1:0].  
Chipcon recommends using a value of 4.  
be  
read  
from  
the  
FREQEST.RX_FREQ_OFFSET[7:0]  
The following procedure should be  
followed when using the AFC to  
register. This is a signed (2’s-complement)  
8-bit value that can be used to  
compensate for frequency offset between  
an external transmitter and the receiving  
device. The frequency offset is given by:  
compensate for  
a
frequency offset  
between transmitter and receiver:  
1. Read  
the  
FREQEST.RX_FREQ_OFFSET[7:  
0] register. This is a signed 2’s-  
complement value.  
F= RX_FREQ_OFFSET x 5.2 [kHz]  
The receiver can be calibrated against an  
external transmitter (another CC2400 or an  
external test signal) by changing the  
operating frequency according to the  
measured offset. The new frequency must  
be calculated by the microcontroller and  
2. Use the equation on this page to  
calculate the frequency offset in  
kHz.  
3. The microcontroller then needs to  
calculate the equivalent value to  
write  
to  
the  
written  
to  
the  
register.  
MDMCTRL.MOD_OFFSET[5:0]  
MDMCTRL.MOD_OFFSET[5:0]  
register.  
After this compensation the center  
frequency of the received signal will better  
match the digital channel filter bandwidth.  
The compensation, as described above,  
also automatically compensates the  
transmitter, i.e. the transmitted signal will  
match the ‘external’ transmitter’s signal.  
However, compensating the transmitter  
signal may cause additional spurs in the  
For example:  
The value read from the  
FREQEST.RX_FREQ_OFFSET[7:0]  
register is 0xE0. This equals –32 since the  
register value is in signed 2’s complement.  
This corresponds to –32 x 5.2 = -166.4  
kHz.  
TX  
spectrum.  
Chipcon  
therefore  
recommends only compensating in RX  
mode.  
The MOD_OFFSETregister should  
therefore be set to –166.4 kHz / 15.625  
kHz = -10.6496 -11. –11 equals 0x35 in  
hexadecimal.  
This feature reduces the requirement on  
the crystal accuracy, which is important  
when using the narrower channel  
bandwidths. For a further description of  
SWRS042A  
Page 42 of 83  
CC2400  
100  
80  
60  
40  
20  
0
AFC with settle = 8  
AFC with settle = 4  
AFC with settle = 2  
AFC with settle = 1  
-500 -450 -400 -350 -300 -250 -200 -150 -100 -50  
0
50 100 150 200 250 300 350 400 450 500 550  
-20  
-40  
-60  
-80  
-100  
Frequency offset [kHz]  
Figure 21. AFC value vs. frequency offset  
33 Linear IF and AGC Settings  
CC2400 is based on a linear IF chain  
where the signal amplification is done in  
an analog VGA (variable gain amplifier).  
The gain of the VGA is controlled by the  
digital part of the IF-chain after the ADC  
(Analog Digital Converter).  
The AGC characteristics are set through  
the AGCCTRL, AGCTST0, AGCTST1and  
AGCTST2registers.  
Note that the RSSI function does not take  
AGC settings into consideration if the AGC  
settings are overridden.  
The AGC (Automatic Gain Control) loop  
ensures that the ADC operates inside its  
dynamic range by using an analog/digital  
feedback loop.  
SWRS042A  
Page 43 of 83  
CC2400  
34 RSSI  
The RSSI measurement can be referred to  
the power at the RF input pins by using  
the following equation:  
CC2400 has a built-in RSSI (Received  
Signal Strength Indicator) giving a digital  
value that can be read form the  
RSSI.RSSI_VAL[7:0]register.  
P = RSSI_VAL+ RSSI_OFFSET[dBm]  
The RSSI reading provides a measure of  
the signal power entering the RF input.  
The scale is logarithmic, so that  
where  
the  
nominal  
value  
of  
RSSI_OFFSET is –54dB. (If the gain in  
the LNA/Mixer is changed from the default  
settings, the offset is changed.)  
RSSI_VALprovides a value in dB.  
The number of samples that are used to  
calculate the average signal amplitude is  
A typical plot of the RSSI_VALreading as  
function of input power is shown in Figure  
22 (for 1Mbps).  
controlled  
by  
the  
RSSI.RSSI_FILT[1:0] register. The  
RSSI filter length (averaging) can be done  
over up to 8 symbols. This will determine  
the response time of the RSSI.  
Note that the RSSI function does not take  
AGC settings into consideration if the AGC  
settings are overridden.  
50  
40  
30  
20  
10  
0
1M  
250kb  
10kb  
-10  
-20  
-30  
-40  
-50  
-60  
Input level (dBm)  
Figure 22. Typical RSSI value vs. input power  
SWRS042A  
Page 44 of 83  
CC2400  
35 Carrier Sense  
The carrier sense signal is based on the  
to a threshold of –70 dBm. A threshold of  
0x09 corresponds to –18 dBm, and a  
threshold of 0x37 corresponds to –90  
dBm.  
measured  
RSSI  
value  
and  
a
programmable threshold. The carrier-  
sense function can be used to simplify the  
implementation of a CSMA (Carrier Sense  
Multiple Access) medium access protocol.  
The carrier sense signal can be  
multiplexed to the GIO1/GIO6 pin. The  
CARRIER_SENSE_N signal is enabled by  
Carrier  
programmed  
RSSI.RSSI_CS_THRES[5:0].  
sense  
threshold  
level  
is  
by  
The  
setting  
IOCFG.GIO1_CFG[5:0]  
01010B(see Table 18).  
=
value of this register can be calculated in  
the same way as described for  
RSSI.RSSI_VAL in the previous section,  
except that the unit is 4 dB instead of 1  
dB. The default level (0x3C) corresponds  
36 Interfacing an External LNA or PA  
the PA / LNA and one or more T/R  
switches.  
CC2400 has two digital output pins, GIO1  
and GIO6, which can be used to control  
an external LNA or PA. The functionality of  
these pins are controlled through the  
IOCFGregister.  
These two pins can also be used as two  
general control signals, see Table 18.  
For further information on attaching a PA,  
please see page 54.  
The PA_EN, PA_EN_N, RX_PD, TX_PD  
signals can be multiplexed to the  
GIO1/GIO6 pin and used for controlling  
37 General Purpose / Test Output Control Pins  
The two digital output pins, GIO1 and  
GIO6, can be used as two general control  
This feature can be used to save I/O pins  
on the microcontroller when the other  
functions associated with these pins are  
not used.  
signals  
by  
writing  
to  
IOCFG.GIO1_CFG[5:0]  
IOCFG.GIO6_CFG[5:0].  
and  
These two pins can also be used as a test  
pin to monitor a lot of internal signals. This  
is summarized in Table 18.  
GIO1_CFG = 61 sets the pin low, and  
GIO1_CFG = 62sets the pin high.  
Signal  
I/O  
Description  
GIO1_CFG /  
GIO6_CFG  
[decimal]  
0
1
2
3
4
5
Reserved  
O
O
O
O
O
O
Reserved  
Reserved  
Reserved  
Reserved  
PA_EN  
PA_EN_N  
SYNC_RECEIVED  
Reserved  
Active high PA enable signal  
Active low PA enable signal  
Set if a valid sync word has been received since last  
time RX was turned on  
Packet status signal See Figure 10, page 28.  
Reserved  
6
7
8
9
PKT  
O
I
O
O
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
SWRS042A  
Page 45 of 83  
CC2400  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
26  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
CARRIER_SENSE_N  
CRC_OK  
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
Carrier sense output (RSSI above threshold)  
CRC check OK after last byte read from FIFO  
AGC enable signal  
AGC_EN  
FS_PD  
Frequency synthesiser power down  
RX power down  
RX_PD  
TX_PD  
TX power down  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
PKT_ACTIVE  
MDM_TX_DIN  
MDM_TX_DCLK  
MDM_RX_DOUT  
MDM_RX_DCLK  
MDM_RX_BIT_RAW  
Reserved  
Packet reception active  
The TX data sent to modem  
The TX clock used by modem  
The RX data received by modem  
The RX clock recovered by modem  
The un-synchronized RX data received by modem  
Reserved  
MDM_BACKEND_EN  
MDM_DEC_OVRFLW  
AGC_CHANGE  
VGA_RESET_N  
CAL_RUNNING  
SETTLING_RUNNING  
RXBPF_CAL_RUNNING  
VCO_CAL_START  
RXBPF_CAL_START  
FIFO_EMPTY  
FIFO_FULL  
The Backend enable signal used by modem in RX  
Modem decimation overflow  
Signal that toggles whenever AGC changes gain.  
The VGA peak detectors' reset signal  
VCO calibration in progress  
Stepping CHP current after calibration  
RX band-pass filter calibration running  
VCO calibration start signal  
RX band-pass filter start signal  
FIFO empty signal  
FIFO full signal  
CLKEN_FS_DIG  
CLKEN_RXBPF_CAL  
CLKEN_GR  
Clock enable Frequency Synthesiser  
Clock enable RX band-pass filter calibration  
Clock enable generic radio  
Indicates that the Main crystal oscillator is stable  
16 MHz XOSC enable signal  
16 MHz XOSC output from analog part  
16 MHz clock from main clock tree  
16 MHz modulator clock tree  
8/16 MHz clock tree for fs_dig module  
8 MHz clock tree derived from XOSC_16M  
8 MHz clock tree for demodulator/AGC  
Reserved  
XOSC16M_STABLE  
XOSC_16M_EN  
XOSC_16M  
CLK_16M  
CLK_16M_MOD  
CLK_8M16M_FSDIG  
CLK_8M  
CLK_8M_DEMOD_AGC  
Reserved  
Reserved  
Reserved  
Reference clock (4 MHz)  
FREF  
FPLL  
Output clock of A/M-counter (4 MHz)  
Phase detector comparator output  
Window signal to PD (Phase Detector)  
Window signal latched in PD (Phase Detector) by the  
FREF clock  
PD_F_COMP  
WINDOW  
LOCK_INSTANT  
58  
59  
60  
61  
62  
63  
RESET_N_SYSTEM  
FIFO_FLUSH  
LOCK_STATUS  
ZERO  
ONE  
HIGH_Z  
O
O
O
O
O
-
Chip wide reset (except registers)  
FIFO flush signal  
The top-level FS in lock status signal  
Output logic zero  
Output logic one  
Pin set as high-impedance output  
Table 18. GIO1 / GIO6 signal select table  
SWRS042A  
Page 46 of 83  
CC2400  
38 Frequency Programming  
The operating frequency is set by  
programming the frequency word in the  
FSDIVconfiguration register.  
f0 = fc fdev  
f1 = fc + fdev  
where fdev is the FSK frequency deviation.  
The frequency word is 12 bits and is  
fdev  
is  
programmed  
with  
located  
in  
FSDIV.FREQ[11:0].  
MDMCTRL.MOD_DEV[6:0] and given by  
(in kHz):  
Writing/reading FSDIV[11:0] will give  
the frequency directly in MHz. (The bits  
FSDIV.FREQ[11:10] are hardwired to  
10’ giving a fixed offset of 2048.)  
fdev = ±3.9062 MOD _ DEV[6 : 0]  
FSDIV should only be modified while the  
CC2400 is in IDLE mode. Otherwise the  
PLL may go out of lock as a calibration is  
only performed when exiting IDLE mode.  
The default value is MOD_DEV = 64 giving  
250 kHz deviation.  
The TX_GAUSSIAN_FILTER bit in the  
GRMDM register controls the Gaussian  
shaping of the modulation signal. See also  
page 38.  
38.1 Transmit mode  
In transmit mode an I/Q direct  
upconversion scheme is used (i.e. no  
intermediate frequency for the modulated  
38.2 Receive mode  
baseband  
signal).  
MDMTST0.TX_1MHZ_OFFSET_N=1 must  
therefore be set during the chip  
initialization sequence (ref. Figure 16).  
Low side LO injection is used, hence:  
f
LO = fRF fIF  
When MDMTST0.TX_1MHZ_OFFSET_N=1  
the transmit channel center frequency  
(carrier frequency), fc, in MHz is given  
directly by:  
where, fRF is the center frequency of the  
channel and fIF = 1 MHz.  
Thus, in receive mode the frequency  
generated by the frequency synthesizer,  
fc, must be programmed to be the LO  
frequency.  
fc = FREQ[11:0]= 2048 +FREQ[9:0]  
The two FSK modulation frequencies are  
given by:  
39 Alternate TX IF setting  
1 MHz in TX has the advantage of much  
lower RX/TX switching time because the  
VCO operates at the same frequency in  
RX and TX.  
It is possible to configure CC2400 to  
operate with an intermediate frequency of  
1 MHz in transmit mode. It is not generally  
recommended to do this, as the TX  
spectrum will have higher spur content  
than when using the direct up conversion  
mode. Using an intermediate frequency of  
1 MHz IF in TX mode is enabled by setting  
MDMTST0.TX_1MHZ_OFFSET_N=0.  
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CC2400  
40 VCO  
The VCO is completely integrated and  
operates at 4800 – 4966 MHz. The VCO  
frequency is divided by 2 to generate  
frequencies in the desired band (2400-  
2483 MHz).  
The VCO frequency is related to  
FSDIV.FREQ[9:0]as follows:  
fVCO = 2
(
2047 + FREQ
[
9:0])  
41 VCO Self-Calibration  
The characteristics of the VCO will vary  
with temperature, changes in supply  
voltages, and the desired operating  
frequency. In order to ensure reliable  
operation the bias current and tuning  
range of the VCO are automatically  
calibrated every time the RX mode or TX  
mode is enabled.  
42 Output Power Programming  
The RF output power from the device is  
programmable and is controlled by the  
FREND.PA_LEVEL[2:0] register. Table  
19 shows the relationship between the  
register value, output power and current  
consumption.  
RF frequency 2.45 GHz  
PA_LEVEL[2:0]  
Output power  
Current  
consumption,  
typ. [mA]  
[binary]  
[dBm]  
000  
001  
010  
011  
100  
101  
110  
111  
-25  
-15  
-10  
-7  
-4.6  
-2.8  
-1.3  
0
11  
12  
13  
14  
16  
17  
18  
19  
Table 19. Output power settings and typical current consumption  
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CC2400  
43 Crystal Oscillator  
An external clock signal or the internal  
crystal oscillator can be used as main  
frequency reference. The reference  
frequency must be 16 MHz. Because the  
crystal frequency is used as reference for  
the data rate as well as other internal  
The crystal oscillator circuit is shown in  
Figure 23. Typical component values for  
different values of CL are given in Table  
20. Note that these values will depend on  
the PCB layout and the crystal used.  
Determination of the values should be  
done by measuring RF frequency on  
several boards and adjusting the values of  
the loading capacitors accordingly.  
signal  
processing  
functions,  
other  
frequencies cannot be used.  
If an external clock signal is used this  
should be connected to XOSC16_Q1,  
while XOSC16_Q2 should be left open. If  
rail-to-rail (1.8V) square-wave signal is  
used, the MAIN.XOSC16M_BYPASS bit  
must be set. It is also possible to use a  
sine-wave input. A voltage swing of 200  
mV peak-to-peak is recommended in this  
case.  
The crystal oscillator is amplitude  
regulated. This means that a high current  
is used to start up the oscillations. When  
the amplitude builds up, the current is  
reduced to what is necessary to maintain  
a stable oscillation. This ensures a fast  
start-up and keeps the drive level to a  
minimum. The ESR of the crystal should  
be within the specification in order to  
ensure  
a
reliable start-up (see the  
Using the internal crystal oscillator, the  
crystal must be connected between the  
XOSC16_Q1 and XOSC16_Q2 pins. The  
oscillator is designed for parallel mode  
operation of the crystal. In addition,  
loading capacitors (C5 and C6) for the  
crystal are required. The loading capacitor  
values depend on the total load  
capacitance, CL, specified for the crystal.  
The total load capacitance seen between  
the crystal terminals should equal CL for  
the crystal to oscillate at the specified  
frequency.  
Electrical Specifications section).  
A small SMD crystal is used in the  
reference design; note that the crystal  
package strongly influences the price. In a  
low-cost design, it may be preferable to  
use a larger crystal package.  
The required accuracy of the crystal is  
determined by the receive filtering. Figure  
19 shows how sensitivity varies with the  
frequency offset between the transmitter  
and the receiver. It is important to take the  
total tolerance of the crystal into  
consideration; this consists of the initial  
tolerance, drift due to temperature and  
aging.  
1
CL  
=
+ C parasitic  
1
1
+
C421 C431  
The parasitic capacitance is constituted by  
pin input capacitance and PCB stray  
capacitance.  
The  
total  
parasitic  
capacitance is typically 5 pF.  
XOSC16_Q1  
XOSC16_Q2  
XTA L  
C421  
C431  
Figure 23. Crystal oscillator circuit  
Item  
C421  
C431  
CL= 16 pF  
22 pF  
22 pF  
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CC2400  
Table 20. 16MHz crystal oscillator component values for CL=16pF  
44 Input / Output Matching  
The RF input / output is differential (RF_N  
and RF_P). In addition there is supply  
switch output pin (TXRX_SWITCH) that  
must have an external DC path to RF_N  
and RF_P.  
Application circuits are shown in Figure 3  
and Figure 4. Component values are given  
in Table 11.  
If a single ended output is required (for a  
single ended connector or a single ended  
antenna), a balun should be used. The  
balun can be realized using discrete  
inductors and capacitors.  
In RX mode the TXRX_SWITCH pin is at  
ground and will bias the LNA. In TX mode  
the TXRX_SWITCH pin is at supply rail  
voltage and will properly bias the internal  
PA.  
Using a differential antenna, no balun is  
required.  
The RF output and DC bias can be  
achieved using different topologies.  
45 Typical performance graphs  
The following graphs show how some  
and should be used as design guidance  
only.  
important  
parameters  
vary  
with  
temperature. These graphs show typical  
performance as a function of temperature,  
25  
24  
23  
22  
21  
20  
19  
18  
17  
16  
15  
RX Current  
TX Current  
-40  
-20  
0
20  
40  
60  
80  
Temp (deg C)  
Figure 24 Typical RX and TX current vs. temperature  
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CC2400  
30  
25  
20  
15  
10  
5
0
-40 -35 -30 -25 -20 -15 -10 -5  
0
5
10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85  
Temp (deg C)  
Figure 25 Typical power-down current vs. temperature  
5
4
3
2
1
0
-1  
-2  
-3  
-4  
-5  
-6  
-40  
-20  
0
20  
40  
60  
80  
Temp (deg C)  
Figure 26 Typical output power vs. temperature  
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CC2400  
-78  
-80  
-82  
-84  
-86  
-88  
-90  
-92  
-40  
-15  
10  
35  
60  
85  
Temperature (deg C)  
Figure 27 Typical 1 Mbps sensitivity vs. temperature  
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CC2400  
46 System Considerations and Guidelines  
will be significantly rejected. This is  
important for all 2.4GHz systems.  
46.1 SRD regulations  
International regulations and national laws  
regulate the use of radio receivers and  
transmitters. SRDs (Short Range Devices)  
for license free operation are allowed to  
operate in the 2.45 GHz bands worldwide.  
The most important regulations are EN  
300 440 and EN 300 328 (Europe), FCC  
CFR47 part 15.247 and 15.249 (USA),  
and ARIB STD-T66 (Japan).  
46.3 Data burst transmissions  
The high maximum data rate of CC2400  
opens up for burst transmissions. A low  
average data rate link (say 10 kbps), can  
be realized using a higher over-the-air  
data rate. Buffering the data and  
transmitting in bursts at high data rate (say  
1 Mbps) will reduce the time in active  
mode, and hence also reduce the average  
current consumption significantly.  
The  
CC2400EM  
reference  
design  
complies with EN 300 440. If frequency  
hopping is to be used at 1 Mbps data rate,  
GFSK should be selected to keep the  
bandwidth below 1 MHz. The CC2400  
complies with EN 300 440 class 2 if the  
band spacing is 2 MHz or more. It  
complies with EN 300 440 class 1 if the  
channel and band spacing is 10 MHz or  
more.  
46.4 Continuous transmissions  
In data streaming applications the CC2400  
opens up for continuous transmissions at  
1 Mbps effective data rate. A typical  
application is digital audio systems. As the  
modulation is done with an I/Q up-  
converter with LO I/Q-signals coming from  
a closed loop PLL, there is no limitation in  
the length of a transmission. (Open loop  
modulation used in some transceivers  
often prevents this kind of continuous data  
streaming and reduces the effective data  
rate.)  
Please note that compliance with  
regulations is dependent on complete  
system performance. It is the customer’s  
responsibility to ensure that the system  
complies with regulations.  
46.5 Crystal drift compensation  
46.2 Frequency hopping and multi-  
channel systems  
A unique feature in CC2400 is the very fine  
frequency  
resolution  
using  
the  
The 2.400 – 2.4835 GHz band is shared  
by many systems both in industrial, office  
and home environment. It is therefore  
recommended to use frequency hopping  
spread spectrum (FHSS) or a multi-  
channel protocol because the frequency  
diversity makes the system more robust  
with respect to interference from other  
systems operating in the same frequency  
band.  
MDMCTRL.MOD_OFFSET[5:0].  
This  
feature can be used to compensate for  
frequency  
offset  
and  
drift.  
The  
compensation affects both the receiver  
and the transmitter of the device being  
compensated. I.e. the received signal of  
the device will match the receiver’s  
channel filter better. In the same way the  
center frequency of the transmitted signal  
will match the ‘external’ transmitter’s  
signal.  
CC2400 is highly suited for FHSS or multi-  
channel systems due to its agile frequency  
synthesizer and effective communication  
interface. Using the packet handling  
support and data buffering is also  
beneficial in such systems as these  
features will significantly offload the host  
controller.  
Initial adjustment can be done using this  
frequency  
programmability.  
This  
eliminates the need for an expensive  
TCXO and trimming in some applications.  
The frequency offset between an ‘external’  
transmitter and the receiver is measured  
in the CC2400 and can be read back from  
an  
internal  
register  
Due to the low-IF I/Q receiver and the on-  
chip complex filtering, the image channel  
(FREQEST.RX_FREQ_OFFSET[7:0]).  
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CC2400  
The measured frequency offset can thus  
be used to calibrate the frequency using  
the ‘external’ transmitter as the reference.  
See also page 42 (Automatic Frequency  
46.8 Low cost systems  
As the CC2400 provides 1 Mbps multi-  
channel performance without any external  
filters, a very low cost system can be  
made.  
Control).  
Figure  
28  
shows  
the  
improvement that can be achieved.  
This feature can also be used for  
temperature compensation of the crystal if  
the temperature drift curve is known and a  
temperature sensor is included in the  
system.  
A differential antenna will eliminate the  
need for a balun, and the DC biasing can  
be achieved in the antenna topology, see  
Figure 4.  
In less demanding applications, a crystal  
with low temperature drift and low aging  
A small SMD crystal is used in the  
reference design; note that the crystal  
package strongly influences the price. In a  
low-cost design, it may be preferable to  
use a larger crystal package.  
could  
be  
used  
without  
further  
compensation.  
46.6 Spectrum efficient modulation  
CC2400 also has the possibility to use  
Gaussian shaped FSK (GFSK). This  
46.9 Battery operated systems  
In low power applications, the power down  
spectrum-shaping  
feature  
improves  
mode should be used when not active.  
adjacent channel power (ACP) and  
occupied bandwidth. In ‘true’ FSK systems  
with abrupt frequency shifting, the  
spectrum is inherently broad. By making  
the frequency shift ‘softer’, the spectrum  
can be made significantly narrower. Thus,  
higher data rates can be transmitted in the  
same bandwidth using GFSK.  
Depending  
on  
the  
start-up  
time  
requirement, the crystal oscillator core can  
be powered during power down. See page  
36 for information on how effective power  
management can be implemented.  
46.10 Increasing output power  
In some applications it may be necessary  
to extend the link range. Adding an  
external power amplifier is the most  
effective way of doing this.  
46.7 Low latency systems  
CC2400 is ideal for applications where  
latency is critical. Unbuffered mode should  
be used for lowest latency, since it takes  
time to fill the FIFO buffer. The total  
latency over the RF link in unbuffered  
mode is around 8 s. CC2400 can also  
provide very low RX-TX switching time, as  
described on page 47.  
The power amplifier should be inserted  
between the antenna and the balun, and  
two T/R switches are needed to  
disconnect the PA in RX mode. See  
Figure 29.  
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CC2400  
0
-10  
-20  
-30  
-40  
-50  
-60  
-70  
-80  
-90  
-100  
With mod_offset compensation  
Without mod_offset compensat  
-350  
-300  
-250  
-200  
-150  
-100  
-50  
0
50  
100  
150  
200  
250  
Frequency offset from center (kHz)  
Figure 28. Sensitivity vs. frequency offset with and without AFC  
Antenna  
Filter  
PA  
Balun  
CC2400  
T/R switch  
T/R switch  
Figure 29. Block diagram of CC2400 usage with external power amplifier  
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CC2400  
47 PCB Layout Recommendations  
A four layer PCB is highly recommended.  
The second layer of the PCB should be  
the “ground-layer”.  
The external components should be as  
small as possible (0402 is recommended)  
and surface mount devices must be used.  
Please note that components smaller than  
those specified may have differing  
characteristics.  
The top layer should be used for signal  
routing, and the open areas should be  
filled with metallization connected to  
ground using several vias.  
Caution should be used when placing the  
The area under the chip is used for  
grounding and must be connected closely  
to the ground plane with several vias.  
microcontroller  
in order  
to avoid  
interference with the RF circuitry.  
A Development Kit with a fully assembled  
Evaluation Module is available. It is  
strongly advised that this reference layout  
is followed very closely in order to achieve  
the best performance.  
The ground pins should be connected to  
ground as close as possible to the  
package pin using individual vias. The de-  
coupling capacitors should also be placed  
as close as possible to the supply pins  
and connected to the ground plane by  
separate vias. Supply power filtering is  
very important.  
The schematic, BOM and layout Gerber  
files for the reference designs are all  
available from the Chipcon website.  
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CC2400  
48 Antenna Considerations  
Non-resonant monopole antennas shorter  
than λ/4 can also be used, but at the  
expense of range. In size and cost critical  
applications such an antenna may very  
well be integrated into the PCB.  
CC2400 can be used together with various  
types of antennas. A differential antenna  
like a dipole would be the easiest to  
interface not needing a balun (balanced to  
un-balanced transformation network).  
Enclosing the antenna in high dielectric  
constant material reduces the overall size  
of the antenna. Many vendors offer such  
antennas intended for PCB mounting.  
The length of the λ/2-dipole antenna is  
given by:  
L = 14250 / f  
where f is in MHz, giving the length in cm.  
An antenna for 2450 MHz should be 5.8  
cm. Each arm is therefore 2.9 cm.  
Helical antennas can be thought of as a  
combination of a monopole and a loop  
antenna. They are a good compromise in  
size critical applications. But helical  
antennas tend to be more difficult to  
optimize than the simple monopole.  
Other commonly used antennas for short-  
range communication are monopole,  
helical and loop antennas. The single-  
ended monopole and helical would require  
a balun network between the differential  
output and the antenna.  
Loop antennas are easy to integrate into  
the PCB, but are less effective due to  
difficult impedance matching because of  
their very low radiation resistance.  
Monopole  
antennas  
are  
resonant  
antennas with a length corresponding to  
one quarter of the electrical wavelength  
(λ/4). They are very easy to design and  
can be implemented simply as a “piece of  
wire” or even integrated into the PCB.  
For low power applications the differential  
antenna is recommended giving the best  
range and because of its simplicity.  
The antenna should be connected as  
close as possible to the IC. If the antenna  
is located away from the RF pins the  
antenna should be matched to the feeding  
transmission line (50 ).  
The length of the λ/4-monopole antenna is  
given by:  
L = 7125 / f  
where f is in MHz, giving the length in cm.  
An antenna for 2450 MHz should be 2.9  
cm.  
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CC2400  
49 Configuration Registers  
initiate the change of an internal state or  
mode.  
The configuration of CC2400 is done by  
programming the 16-bit configuration  
registers. The configuration data based on  
selected system parameters are most  
easily found by using the SmartRFStudio  
software. Complete descriptions of the  
registers are given in the following tables.  
After a RESET is programmed, all the  
registers have default values as shown in  
the tables.  
The FIFO is accessed as an 8-bit register.  
Some registers contain signed values.  
These are in two’s complement format. I.e.  
for a 4-bit value, 0000 is 0, 1111 is –1,  
1110 is –2, 1000 is -8 and 0111 is 7.  
During the address transfer a status byte  
is returned. This status byte is described  
in Table 13 at page 23.  
Some registers are Strobe Command  
Registers. Accessing these registers will  
Overview of CC2400 ‘s control registers  
Register name  
Description  
0x00  
0x01  
0x02  
0x03  
0x04  
0x05  
0x06  
0x07  
0x08  
0x09  
0x0A  
0x0B  
0x0C  
0x0D  
0x0E  
0x0F  
0x10  
0x11  
0x12  
0x13  
0x14  
0x15  
0x16  
0x17  
0x18  
0x19  
0x1A  
0x1B  
0x1C  
0x1D  
0x1E  
0x1F  
0x20  
0x21  
MAIN  
FSCTRL  
FSDIV  
MDMCTRL  
AGCCTRL  
FREND  
RSSI  
FREQEST  
IOCFG  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
Main control register  
Frequency synthesiser main control and status  
Frequency synthesiser frequency division control  
Modem main control and status  
AGC main control and status  
Analog front-end control  
RSSI information  
Received signal frequency offset estimation  
I/O configuration register  
Unused  
Unused  
Finite state machine time constants  
Reserved register containing spare control and status bits  
Manual signal AND-override register  
Finite state machine information and breakpoint  
ADC test register  
Receiver bandpass filters test register  
PA and transmit mixers test register  
LNA and receive mixers test register  
Manual signal OR-override register  
Modem test register 0  
FSMTC  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R
RESERVED  
MANAND  
FSMSTATE  
ADCTST  
RXBPFTST  
PAMTST  
LMTST  
MANOR  
MDMTST0  
MDMTST1  
DACTST  
AGCTST0  
AGCTST1  
AGCTST2  
FSTST0  
FSTST1  
FSTST2  
FSTST3  
MANFIDL  
MANFIDH  
GRMDM  
Modem test register 1  
DAC test register  
AGC test register: various control and status.  
AGC test register: AGC timeout.  
AGC test register: AGC various parameters.  
Test register: VCO array results and override.  
Test register: VC DAC manual control. VCO current constant.  
Test register:VCO current result and override.  
Test register: Charge pump current etc.  
Manufacturer ID, lower 16 bit  
R
R/W  
R/W  
Manufacturer ID, upper 16 bit  
Generic radio modem control  
Generic radio decimation control and status  
GRDEC  
1 R/W - Read/write (control/status), R - Status only, S – Strobe command register (perform action upon access)  
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CC2400  
Register name  
Description  
0x22  
0x23  
0x24  
0x25  
0x26  
0x27  
0x28  
0x29  
0x2A  
0x2B  
0x2C  
0x2D  
...  
PKTSTATUS  
INT  
R
Packet mode status  
Interrupt register  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
SYNCL  
Synchronisation word, lower 16 bit.  
Synchronisation word, upper 16 bit.  
SYNCH  
0x60  
0x61  
SXOSCON  
SFSON  
S
S
Command strobe register: Turn on XOSC.  
Command strobe register: Start and calibrate FS and go from RX/TX to a wait  
mode where the FS is running.  
Command strobe register: Start RX.  
Command strobe register: Start TX (turn on PA).  
Command strobe register: Turn off RX/TX and FS.  
Command strobe register: Turn off XOSC.  
0x62  
0x63  
0x64  
0x65  
0x66  
0x67  
0x68  
0x69  
0x6A  
0x6B  
0x6C  
0x6D  
0x6E  
0x6F  
0x70  
SRX  
STX  
SRFOFF  
S
S
S
S
S
S
S
S
S
S
S
S
S
S
SXOSCOFF  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
Reserved  
FIFOREG  
Special  
Used to write data to and read data from the 8-bit wide 32 bytes FIFO used to  
buffer outgoing TX data and incoming RX data in buffered RF mode.  
MAIN (0x00) - Main Control Register  
Bit  
Field Name  
Reset  
R/W  
Description  
15  
RESETN  
-
R/W  
Active low reset of entire circuit. Should be applied before doing  
anything else.  
14:10  
9
-
0
0
W0  
Reserved, write as 0.  
FS_FORCE_EN  
R/W  
Forces the frequency synthesiser on (starts with a calibration).  
The synthesiser can also be turned on in a number of other  
ways.  
8
RXN_TX  
0
R/W  
Selects whether RX operation ('0') or TX operation ('1') is desired  
when FS_FORCE_EN is used. RX or TX mode is usually  
selected using the SRX and STX strobe commands (or RX and  
TX pins).  
7:4  
3
-
0
0
0
0
W0  
Reserved, write as 0.  
Reserved, write as 0.  
Reserved, write as 0.  
-
R/W  
R/W  
R/W  
2
-
1
XOSC16M_BYPASS  
Bypasses the 16 MHz main crystal oscillator and uses a buffered  
version of the signal on Q1 directly. Used for external clock only.  
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CC2400  
Bit  
Field Name  
Reset  
R/W  
Description  
0
XOSC16M_EN  
0
R/W  
Forces the 16 MHz main crystal oscillator and the global bias on.  
These modules can also be turned on in other ways.  
FSCTRL (0x01) - Frequency Synthesiser Control and Status  
Bit  
15:6  
5:4  
Field Name  
Reset  
R/W  
W0  
Description  
-
0
1
Reserved, write as 0.  
LOCK_THRESHOLD[1:0]  
R/W  
Number of consecutive reference clock periods with successful  
sync windows required to indicate lock:  
0: 64  
1: 128  
2: 256  
3: 512  
3
CAL_DONE  
0
R
Calibration has been performed since the last time the FS was  
turned on.  
2
1
CAL_RUNNING  
LOCK_LENGTH  
0
0
R
Calibration status, '1' when calibration in progress.  
LOCK_WINDOW pulse width:  
0: 2 CLK_PRE periods  
R/W  
1: 4 CLK_PRE periods  
0
LOCK_STATUS  
0
R
'1' when PLL is in lock, otherwise '0'.  
FSDIV (0x02) - Frequency Synthesiser Frequency Division Control  
Bit  
Field Name  
-
Reset  
R/W  
W0  
R
Description  
15:12  
11:10  
0
2
Reserved, write as 0.  
Read only.  
FREQ[11:10]  
Directly gives the right frequency in MHz when reading/writing  
FREQ[11:0].  
9:0  
FREQ[9:0]  
353  
R/W  
Frequency control word.  
[MHz]  
fc = FREQ 11:0 = 2048 + FREQ 9:0  
[ ] [ ]  
where fc is the channel centre frequency. See page 47 for a  
description of how to program the channel for tansmit and  
receive modes respectively.  
Reading/writing FREQ[11:0]gives the right frequency in MHz.  
The default value corresponds to fc=2401MHz.  
MDMCTRL (0x03) - Modem Control and Status  
Bit  
15:13  
12:7  
Field Name  
Reset  
R/W  
W0  
Description  
-
0
0
Reserved, write as 0.  
MOD_OFFSET[5:0]  
R/W  
Modulator/Demodulator centre frequency in 15.625 kHz steps  
(for the receiver the steps are relative to 1 MHz, for the  
transmitter the steps are relative to 0MHz when  
MDMTST0.TX_1MHZ_OFFSET_N=1).  
Two's complement signed value. I.e. MOD_OFFSET=0x1F Î  
centre frequency=1.48 MHz; MOD_OFFSET=0x20Î centre  
SWRS042A  
Page 60 of 83  
CC2400  
Bit  
Field Name  
Reset  
R/W  
Description  
frequency=0.50 MHz.  
6:0  
MOD_DEV[6:0]  
64  
R/W  
Modulator frequency deviation in 3.9062 kHz steps (0-500 kHz).  
Unsigned value. Reset value gives a deviation of 250 kHz.  
AGCCTRL (0x04) - AGC Control and Status  
Bit  
Field Name  
Reset  
R/W  
Description  
15:8  
VGA_GAIN [7:0]  
0XF7  
R/W  
When written, VGA manual gain override value; when read, the  
currently used VGA gain setting.  
7:4  
3
-
0
0
0
0
W0  
Reserved, write as 0.  
AGC_LOCKED  
AGC_LOCK  
AGC_SYNC_LOCK  
R
AGC lock status  
2
R/W  
R/W  
Lock gain after maximum number of attempts.  
1
Lock gain after sync word received and maximum number of  
attempts. (As configured in AGCTST0.AGC_ATTEMPTS. Attempts  
may be 0)  
0
VGA_GAIN_OE  
0
R/W  
Use the VGA_GAINvalue during RX instead of the AGC value.  
FREND (0x05) – Front-end Control Register  
Bit  
15:4  
3
Field Name  
Reset  
R/W  
W0  
Description  
-
0
1
7
Reserved, write as 0.  
Reserved, write as 1.  
PA output power level.  
-
W1  
2:0  
PA_LEVEL[2:0]  
R/W  
RSSI (0x06) - RSSI Status and Control Register  
Bit  
Field Name  
Reset  
R/W  
Description  
15:8  
RSSI_VAL[7:0]  
-
R
Averaged RSSI estimate on a logarithmic scale in signed two’s  
complement format. Unit is 1 dB.  
Offset= -54dB, see also page 44.  
7:2  
RSSI_CS_THRES[5:0]  
0X3C  
R/W  
Carrier sense signal threshold value in signed two’s complement  
format. Unit is 4 dB.  
The CS_ABOVE_THRESHOLD_N signal goes low when the  
received signal is above this value.  
The CS_ABOVE_THRESHOLD_N signal is available on the  
GIO1 pin or in the status word returned during SPI address byte.  
The reset value corresponds to a threshold of approx. -69 dBm.  
1:0  
RSSI_FILT[1:0]  
2
R/W  
RSSI averaging filter length:  
0: 0 bits (no filtering)  
1: 1 bit  
2: 4 bits  
3: 8 bits  
SWRS042A  
Page 61 of 83  
CC2400  
FREQEST (0x07) - Received frequency offset estimation  
Bit  
Field Name  
Reset  
R/W  
Description  
15:8  
RX_FREQ_OFFSET[7:0]  
-
R
Estimate of the received signals centre frequency comparison to  
the ideal 1 MHz centre frequency. Two's complement signed  
value. See page 42.  
7:0  
-
0
W0  
Reserved, write as 0.  
IOCFG (0x08) - I/O configuration register  
Bit  
Field Name  
Reset  
0
R/W  
W0  
Description  
15  
-
Reserved, write as 0.  
14:9  
GIO6_CFG[5:0]  
11  
R/W  
Configuration of the GIO6 pin. See page 45 for options. The  
reset value outputs the signal CRC_OK on pin GIO6.  
8:3  
GIO1_CFG[5:0]  
HSSD_SRC[2:0]  
60  
0
R/W  
R/W  
How to use the GIO1 pin. See page 45 for options. The reset  
value outputs the signal LOCK_STATUS on pin GIO1.  
2:0  
For test purposes only.  
The HSSD (High Speed Serial Data) test module is used as  
follows:  
0: Off.  
1: Output AGC status (gain setting / peak detector status /  
accumulator value)  
2: Output ADC I and Q values.  
3: Output I/Q after digital down-mixing and channel filtering.  
4: Output RX signal magnitude / frequency unfiltered (from  
demodulator).  
5: Output RX signal magnitude / frequency filtered (from  
demodulator).  
6: Output RSSI / RX frequency offset estimation  
7: Input DAC values.  
The HSSD test module requires that the FS is up and running as  
it uses CLK_PRE (~150 MHZ) to produce its ~37.5 MHz data  
clock and serialize its output words. Also, in order for HSSD to  
function properly GRMDM.PIN_MODEmust be set for HSSD.  
FSMTC (0x0B) - Finite state machine time constants  
Bit  
Field Name  
Reset  
R/W  
Description  
15:13  
TC_RXON2AGCEN[2:0]  
3
R/W  
The time in 5 s steps from RX is turned on until the AGC is  
enabled. This time constant must be large enough to allow the  
RX chain to settle so that the AGC algorithm starts working on a  
proper signal. The default value corresponds to 15 us.  
12:10  
TC_PAON2SWITCH[2:0]  
6
R/W  
The time in s from TX is started until the TX/RX switch allows  
the TX signal to pass.  
9:6  
5:3  
RES[9:6]  
10  
2
R/W  
R/W  
Reserved  
TC_TXEND2SWITCH[2:0]  
The time in s from TX is stopped (for instance the last bit of the  
packet is sent) until the RX/TX switch breaks the TX output and  
the PKT signal is set.  
SWRS042A  
Page 62 of 83  
CC2400  
Bit  
2:0  
Field Name  
Reset  
R/W  
Description  
TC_TXEND2PAOFF[2:0]  
4
R/W  
The time in s from TX is stopped until the TX chain is turned off  
and the state machine goes to the next state. The PKT signal will  
then go low. This value must be greater than  
TC_TXEND2SWITCH[2:0].  
RESERVED (0x0C) - Reserved register containing spare control and status bits  
Bit  
15:5  
4:0  
Field Name  
RES[15:5]  
RES[4:0]  
Reset  
R/W  
R/W  
R/W  
Description  
Reserved  
Reserved  
0
0
MANAND (0x0D) - Manual signal AND override register2  
Bit  
Field Name  
Reset  
R/W  
Description  
15  
VGA_RESET_N  
1
R/W  
Overrides VGA_RESET_N used to reset the peak detectors in  
the VGA in the RX chain.  
Must be set to 0 during chip initialization.  
14  
13  
LOCK_STATUS  
BALUN_CTRL  
1
1
R/W  
R/W  
Overrides the LOCK_STATUS top-level signal that indicates  
whether VCO lock is achieved or not.  
Overrides the BALUN_CTRL signal that controls whether the PA  
should receive its required external biasing (1) or not (0) by  
controlling the RX/TX output switch.  
12  
RXTX  
1
R/W  
Overrides the RXTX signal that controls whether the LO buffers  
(0) or PA buffers (1) should be used.  
11  
10  
9
PRE_PD  
1
1
1
R/W  
R/W  
R/W  
Power down of prescaler.  
PA_N_PD  
PA_P_PD  
Power down of PA (negative path).  
Power down of PA (positive path). When PA_N_PD=1 and  
PA_P_PD=1 the up-conversion mixers are in powerdown.  
8
7
DAC_LPF_PD  
BIAS_PD  
1
1
R/W  
R/W  
Power down of TX DACs.  
Power down control of global bias generator + XOSC clock  
buffer.  
6
5
4
XOSC16M_PD  
CHP_PD  
1
1
1
R/W  
R/W  
R/W  
Power down control of 16 MHz XOSC core.  
Power down control of charge pump.  
FS_PD  
Power down control of VCO, I/Q generator, LO buffers.  
2
For some important signals the value can be overridden manually by the MANAND and MANOVR registers. This is  
done as follows for the hypothetical important signal IS:  
IS_USED = (IS * IS_AND_MASK) + IS_OR_MASK,  
using Boolean notation.  
The AND-mask and OR-mask for the important signals listed resides in the MANAND and MANOR registers,  
respectively.  
Examples:  
Writing 0xFFFE to MANAND and 0x0000 to MANOR will force LNAMIX_PD=0 whereas all other signals will be  
unaffected.  
Writing 0xFFFF to MANAND and 0x0001 to MANOVR will force LNAMIX_PD=1 whereas all other signals will be  
unaffected.  
SWRS042A  
Page 63 of 83  
CC2400  
Bit  
Field Name  
ADC_PD  
Reset  
R/W  
R/W  
R/W  
R/W  
R/W  
Description  
3
2
1
0
1
1
1
1
Power down control of the ADCs.  
Power down control of the VGA.  
VGA_PD  
RXBPF_PD  
LNAMIX_PD  
Power down control of the band-pass receive filter.  
Power down control of the LNA, down-conversion mixers and  
front-end bias.  
FSMSTATE (0x0E) - Finite state machine information and breakpoint  
Bit  
15:13  
12:8  
Field Name  
Reset  
R/W  
W0  
Description  
-
0
0
Reserved, write as 0.  
FSM_STATE_BKPT[4:0]  
R/W  
FSM breakpoint state. State=0 means that breakpoints are  
disabled.  
7:5  
4:0  
-
0
-
W0  
R
Reserved, write as 0.  
FSM_CUR_STATE[4:0]  
Gives the current state of the finite state machine.  
ADCTST (0x0F) - ADC Test Register  
Bit  
Field Name  
Reset  
R/W  
W0  
R
Description  
15  
-
0
-
0
-
Reserved, write as 0.  
14:8  
7
ADC_I[6:0]  
-
Read the current ADC I-branch value.  
Reserved, write as 0.  
W0  
R
6:0  
ADC_Q[6:0]  
Read the current ADC Q-branch value.  
RXBPFTST (0x10) - Receiver Band-pass Filters Test Register  
Bit  
Field Name  
Reset  
R/W  
W0  
Description  
15  
14  
-
0
0
0
-
Reserved, write as 0.  
RXBPF_CAP_OE  
RXBPF_CAP_O[6:0]  
RXBPF_CAP_RES[6:0]  
R/W  
R/W  
R
RX band-pass filter capacitance calibration override enable.  
RX band-pass filter capacitance calibration override value.  
RX band-pass filter capacitance calibration result.  
0 Minimum capacitance in the feedback.  
1: Second smallest capacitance setting.  
13:7  
6:0  
127: Maximum capacitance in the feedback.  
SWRS042A  
Page 64 of 83  
CC2400  
PAMTST (0x11) - PA and Transmit Mixers Test Register  
Bit  
15:13  
12  
Field Name  
Reset  
R/W  
W0  
Description  
-
0
0
Reserved, write as 0.  
VC_IN_TEST_EN  
R/W  
When ATESTMOD_MODE=7 this controls whether the ATEST1 in  
is used to output the VC node voltage (0) or to control the VC  
node voltage (1).  
11  
ATESTMOD_PD  
1
0
W
Power down of the analog test module.  
10:8  
ATESTMOD_MODE[2:0]  
R/W  
When ATESTMOD_PD=0, the function of the analog test module  
is as follows:  
0: Outputs “I” (ATEST2) and “Q” (ATEST1) from RxMIX.  
1: Inputs “I” (ATEST2) and “Q” (ATEST1) to BPF.  
2: Outputs “I” (ATEST2) and “Q” (ATEST1) from VGA.  
3: Inputs “I” (ATEST2) and “Q” (ATEST1) to ADC.  
4: Outputs “I” (ATEST2) and “Q” (ATEST1) from LPF.  
5: Inputs “I” (ATEST2) and “Q” (ATEST1) to TxMIX.  
6: Outputs “P” (ATEST2) and “N” (ATEST1) from Prescaler.  
7: Connects TX IF to RX IF and simultaneously the ATEST1 pin to the  
internal VC node (see VC_IN_TEST_EN).  
7
-
0
0
0
W0  
Reserved, write as 0.  
Selects varactor array settings in the transmit mixers.  
Transmit mixers current:  
0: 1.72 mA  
6:5  
4:3  
TXMIX_CAP_ARRAY[1:0]  
TXMIX_CURRENT[1:0]  
R/W  
R/W  
1: 1.88 mA  
2: 2.05 mA  
3 2.21 mA  
2:0  
PA_CURRENT[2:0]  
3
R/W  
Programming of the PA current  
0: -3 current adjustment  
1: -2 current adjustment  
2: -1 current adjustment  
3: Nominal setting  
4: +1 current adjustment  
5: +2 current adjustment  
6: +3 current adjustment  
7: +4 current adjustment  
SWRS042A  
Page 65 of 83  
CC2400  
LMTST (0x12) - LNA and receive mixers test register  
Bit  
15:14  
13  
Field Name  
-
Reset  
R/W  
W0  
Description  
0
1
1
Reserved, write as 0.  
RXMIX_HGM  
RXMIX_TAIL[1:0]  
R/W  
R/W  
Receiver mixers high gain mode enable.  
Control of the receiver mixers output current.  
0: 12 µA  
12:11  
1: 16 µA (Nominal)  
2: 20 µA  
3:24 µA  
10:9  
RXMIX_VCM[1:0]  
1
R/W  
Controls VCM level in the mixer feedback loop  
0: 8 µA mixer current  
1: 12 µA mixer current (Nominal)  
2: 16 µA mixer current  
3: 20 µA mixer current  
Must be set to 0 during chip initialisation.  
Controls current in the mixer  
0: 360 µA mixer current (x2)  
1: 720 µA mixer current (x2)  
2: 900 µA mixer current (x2) (Nominal)  
3: 1260 µA mixer current (x2)  
Selects varactor array setting in the LNA  
0: OFF  
8:7  
6:5  
RXMIX_CURRENT[1:0]  
LNA_CAP_ARRAY[1:0]  
2
1
R/W  
R/W  
1: 0.1pF (x2) (Nominal)  
2: 0.2pF (x2)  
3: 0.3pF (x2)  
4
LNA_LOWGAIN  
0
0
R/W  
R/W  
Selects low gain mode of the LNA  
0: 19 dB (Nominal)  
1: 7 dB  
3:2  
LNA_GAIN[1:0]  
Controls current in the LNA gain compensation branch  
0: OFF (Nominal)  
1: 100 µA LNA current  
2: 300 µA LNA current  
3: 1000 µA LNA current  
1:0  
LNA_CURRENT[1:0]  
2
R/W  
Controls main current in the LNA  
0: 240 µA LNA current (x2)  
1: 480 µA LNA current (x2)  
2: 640 µA LNA current (x2) (Nominal)  
3: 1280 µA LNA current (x2)  
SWRS042A  
Page 66 of 83  
CC2400  
MANOR (0x13) - Manual signal OR override register3  
Bit  
Field Name  
Reset  
R/W  
Description  
15  
14  
13  
VGA_RESET_N  
0
R/W  
Overrides VGA_RESET_N used to reset the peak detectors in  
the VGA in the RX chain.  
LOCK_STATUS  
BALUN_CTRL  
0
0
R/W  
R/W  
Overrides the LOCK_STATUS top-level signal that indicates  
whether VCO lock is achieved or not.  
Overrides the BALUN_CTRL signal that controls whether the PA  
should receive its required external biasing (1) or not (0) by  
controlling the RX/TX output switch.  
12  
RXTX  
0
R/W  
Overrides the RXTX signal that controls whether the LO buffers  
(0) or PA buffers (1) should be used.  
11  
10  
9
PRE_PD  
0
0
0
R/W  
R/W  
R/W  
Power down of prescaler.  
PA_N_PD  
PA_P_PD  
Power down of PA (negative path).  
Power down of PA (positive path). When PA_N_PD=1 and  
PA_P_PD=1 the up-conversion mixers are in power down.  
8
7
DAC_LPF_PD  
BIAS_PD  
0
0
R/W  
R/W  
Power down of TX DACs.  
Power down control of global bias generator + XOSC clock  
buffer.  
6
5
4
3
2
1
0
XOSC16M_PD  
CHP_PD  
0
0
0
0
0
0
0
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
Power down control of 16 MHz XOSC core.  
Power down control of charge pump.  
FS_PD  
Power down control of VCO, I/Q generator, LO buffers.  
Power down control of the ADCs.  
ADC_PD  
VGA_PD  
Power down control of the VGA.  
RXBPF_PD  
LNAMIX_PD  
Power down control of complex band-pass receive filter.  
Power down control of LNA, down-conversion mixers and front-  
end bias.  
MDMTST0 (0x14) - Modem Test Register 0  
Bit  
15:14  
13  
Field Name  
-
Reset  
R/W  
W0  
Description  
0
0
Reserved, write as 0.  
TX_PRNG  
R/W  
When set, the transmitted data is taken from a 10-bit PRNG  
instead of from the DIO pin in un-buffered mode or from the  
FIFO in buffered mode.  
12  
TX_1MHZ_OFFSET_N  
0
R/W  
Determines TX IF frequency:  
0: 1 MHz (Not used)  
1: 0 MHz (During initialization this bit must be set to a logical ’1’.)  
11  
10  
INVERT_DATA  
0
0
R/W  
R/W  
When this bit is set the data are inverted (internally) before  
transmission, and inverted after reception.  
AFC_ADJUST_ON_PACKET  
When this bit is set to '1', modem parameters are adjusted for  
slow tracking of the received signal as opposed to quick  
acquisition when a packet is received in RX.  
3 See footnote for MANAND register (address 0x0D) for description of the use of this register.  
SWRS042A  
Page 67 of 83  
CC2400  
Bit  
9:8  
Field Name  
Reset  
R/W  
Description  
AFC_SETTLING[1:0]  
3
R/W  
Controls how many max-min pairs that are used to compute the  
output.  
00: 1 pair  
01: 2 pairs  
10: 4 pairs  
11: 8 pairs  
7:0  
AFC_DELTA[7:0]  
75  
R/W  
Programmable level used in AFC-algorithm that indicates the  
expected frequency deviation of the received signal. See page  
42 for further details.  
MDMTST1 (0x15) - Modem Test Register 1  
Bit  
15:7  
6:0  
Field Name  
Reset  
0
R/W  
W0  
Description  
-
Reserved, write as 0.  
BSYNC_THRESHOLD[6:0]  
75  
R/W  
Threshold value used in clock recovery algorithm. Sets the level  
for when re-synchronization takes place.  
DACTST (0x16) - DAC Test Register  
Reset  
Bit  
Field Name  
R/W  
Description  
15  
-
0
0
W0  
Reserved, write as 0.  
14:12  
DAC_SRC[2:0]  
R/W  
The TX DACs data source is selected by DAC_SRC according  
to:  
0: Normal operation (from modulator).  
1: The DAC_I_O and DAC_Q_O override values below.  
2: From ADC  
3: I/Q after digital down-mixing and channel filtering.  
4: Full-spectrum White Noise (from PRNG.)  
5: RX signal magnitude / frequency filtered (from demodulator).  
6: RSSI / RX frequency offset estimation.  
7: HSSD module.  
This feature will often require the DACs to be manually turned on  
in MANOVRand PAMTST.ATESTMOD_MODE=4.  
11:6  
5:0  
DAC_I_O[5:0]  
DAC_Q_O[5:0]  
0
0
R/W  
R/W  
I-branch DAC override value.  
Q-branch DAC override value.  
SWRS042A  
Page 68 of 83  
CC2400  
AGCTST0 (0x17) - AGC Test Register 0  
Bit  
Field Name  
Reset  
R/W  
Description  
15:13  
AGC_SETTLE_BLANK_DN[2:  
0]  
4
R/W  
AGC blanking enable/limit for negative gain changes.  
0: Disabled  
1-7: Duration of blanking signal in 8 MHz clock cycles.  
AGC window size.  
12:11  
10:7  
6:3  
AGC_WIN_SIZE[1:0]  
AGC_SETTLE_PEAK[3:0]  
AGC_SETTLE_ADC[3:0]  
AGC_ATTEMPTS[2:0]  
2
2
2
0
R/W  
R/W  
R/W  
R/W  
AGC peak detectors settling period.  
AGC ADC settling period.  
2:0  
The maximum number of attempts to set the gain.  
AGCTST1 (0x18) - AGC Test Register 1  
Bit  
Field Name  
Reset  
R/W  
W0  
Description  
15  
14  
-
0
1
Reserved, write as 0.  
AGC_VAR_GAIN_SAT  
R/W  
Chooses the gain reduction upon saturation of the variable  
gain stage:  
0: -1/-3 gain steps  
1: -3/-5 gain steps  
13:11  
10  
AGC_SETTLE_BLANK_UP  
[2:0]  
0
0
R/W  
R/W  
AGC blanking enable/limit for positive gain changes.  
0: Disabled  
1-7: Duration of blanking signal in 8 MHz clock cycles.  
PEAKDET_CUR_BOOST  
Doubles the bias current in the peak-detectors in-between the  
VGA stages when set.  
9:6  
5:2  
1:0  
AGC_MULT_SLOW[3:0]  
AGC_SETTLE_FIXED[3:0]  
AGC_SETTLE_VAR[1:0]  
0
4
0
R/W  
R/W  
R/W  
AGC timing multiplier, slow mode.  
AGC settling period, fixed gain step.  
AGC settling period, variable gain step.  
AGCTST2 (0x19) - AGC Test Register 1  
Bit  
Field Name  
Reset  
R/W  
Description  
15:14  
13:12  
-
0
0
W0  
Reserved, write as 0.  
AGC_BACKEND_BLANKING  
[1:0]  
R/W  
AGC blanking makes sure that the modem locks its bit  
synchronization and centre frequency estimator when the AGC  
changes the gain.  
0: Disabled  
1-3: Fixed/variable enable  
AGC parameter -3 dB.  
AGC parameter -1 dB.  
AGC parameter +3 dB.  
AGC parameter +1 dB.  
11:9  
8:6  
5:3  
2:0  
AGC_ADJUST_M3DB[2:0]  
AGC_ADJUST_M1DB[2:0]  
AGC_ADJUST_P3DB[2:0]  
AGC_ADJUST_P1DB[2:0]  
0
0
0
0
R/W  
R/W  
R/W  
R/W  
SWRS042A  
Page 69 of 83  
CC2400  
FSTST0 (0x1A) - Frequency Synthesiser Test Register 0  
Bit  
Field Name  
Reset  
R/W  
Description  
15:14  
RXMIXBUF_CUR[1:0]  
2
R/W  
RX mixer buffer bias current.  
0: 690uA  
1: 980uA  
2: 1.16mA (nominal)  
3: 1.44mA  
13:12  
TXMIXBUF_CUR[1:0]  
2
0
R/W  
R/W  
TX mixer buffer bias current.  
0: 690uA  
1: 980uA  
2: 1.16mA (nominal)  
3: 1.44mA  
11  
VCO_ARRAY_SETTLE_LONG  
When '1' this control bit doubles the time allowed for VCO  
settling during FS calibration.  
10  
VCO_ARRAY_OE  
0
R/W  
R/W  
R
VCO array manual override enable.  
9:5  
4:0  
VCO_ARRAY_O[4:0]  
VCO_ARRAY_RES[4:0]  
16  
-
VCO array override value.  
The resulting VCO array setting from the last calibration.  
FSTST1 (0x1B) - Frequency Synthesiser Test Register 1  
Bit  
Field Name  
Reset  
R/W  
Description  
15  
14  
RXBPF_LOCUR  
0
R/W  
Controls reference bias current to RX band-pass filters:  
0: 4 uA (nominal)  
1: 3 uA  
RXBPF_MIDCUR  
0
R/W  
Controls reference bias current to RX band-pass filters:  
0: 4 uA (nominal)  
1: 3.5 uA  
13:10  
9:4  
3
VCO_CURRENT_REF[3:0]  
VCO_CURRENT_K[5:0]  
VC_DAC_EN  
4
0
0
R/W  
R/W  
R/W  
The value of the reference current calibrated against during VCO  
calibration.  
VCO current calibration constant (override value current B when  
FSTST2.VCO_CURRENT_OE=1).  
Controls the source of the VCO control voltage in normal  
operation (PAMTST.VC_IN_TEST_EN=0):  
0: Loop filter (closed loop PLL)  
1: VC DAC (open loop PLL)  
2:0  
VC_DAC_VAL[2:0]  
2
R/W  
VC DAC output value. (The value of the reference voltage used  
during VCO calibration.)  
SWRS042A  
Page 70 of 83  
CC2400  
FSTST2 (0x1C) - Frequency Synthesiser Test Register 2  
Bit  
Field Name  
Reset  
R/W  
W0  
Description  
15  
-
0
0
Reserved, write as 0.  
VCO current calibration speed:  
0: Normal  
14:13  
VCO_CURCAL_SPEED[1:0]  
R/W  
1: Undefined  
2: Half speed  
3: Undefined.  
12  
VCO_CURRENT_OE  
0
R/W  
R/W  
R
VCO current manual override enable.  
11:6  
5:0  
VCO_CURRENT_O[5:0]  
VCO_CURRENT_RES[5:0]  
24  
-
VCO current override value (current A).  
The resulting VCO current setting from last calibration.  
FSTST3 (0x1D) - Frequency Synthesiser Test Register 3  
Bit  
15:14  
13  
Field Name  
-
Reset  
R/W  
W0  
Description  
0
0
0
Reserved, write as 0.  
CHP_TEST_UP  
CHP_TEST_DN  
R/W  
R/W  
When CHP_DISABLE=1forces the CHP to output "up" current.  
12  
When CHP_DISABLE=1forces the CHP to output "down"  
current.  
11  
10  
CHP_DISABLE  
PD_DELAY  
0
0
R/W  
R/W  
Set to disable charge pump during VCO calibration.  
Selects short or long reset delay in phase detector:  
0: Short reset delay  
1: Long reset delay  
9:8  
CHP_STEP_PERIOD[1:0]  
STOP_CHP_CURRENT[3:0]  
2
R/W  
The charge pump current value step period:  
0: 0.25 us  
1: 0.5 us  
2: 1 us  
3: 4 us  
7:4  
3:0  
13  
13  
R/W  
R/W  
The charge pump current to stop at after the current is stepped  
down from START_CHP_CURRENTafter VCO calibration is  
complete. The current is stepped down periodically with intervals  
as defined in CHP_STEP_PERIOD.  
START_CHP_CURRENT  
[3:0]  
The charge pump current to start with after VCO calibration is  
complete. The current is then stepped down periodically to the  
value STOP_CHP_CURRENTwith intervals as defined in  
CHP_STEP_PERIOD.  
SWRS042A  
Page 71 of 83  
CC2400  
MANFIDL (0x1E) - Manufacturer ID, Lower 16 Bit  
Bit  
15:12  
11:0  
Field Name  
Reset  
1
R/W  
R
Description  
PARTNUM[3:0]  
MANFID[11:0]  
The device part number. CC2400 has part number 0x001.  
0X33D  
R
Gives the JEDEC manufacturer ID. The actual manufacturer ID  
can be found in MANIFID[7:1], the number of continuation  
bytes in MANFID[11:8]and MANFID[0]=1.  
Chipcon's JEDEC manufacturer ID is 0x7F 0x7F 0x7F 0x9E  
(0x9E preceded by three continuation bytes.)  
MANFIDH (0x1F) - Manufacturer ID, Upper 16 Bit  
Bit  
15:12  
11:0  
Field Name  
Reset  
R/W  
R
Description  
VERSION[3:0]  
PARTNUM[15:4]  
0
0
Chip version number.  
R
The device part number. CC2400 has part number 0x001.  
GRMDM (0x20) - Generic Radio Modem Control and Status  
Bit  
Field Name  
Reset  
R/W  
W0  
Description  
15  
-
0
0
Reserved, write as 0.  
14:13  
12:11  
SYNC_ERRBITS_ALLOWED  
[1:0]  
R/W  
Sync word detection occurs when the number of bits in the sync  
word correlator different from that specified by the SYNC  
registers is equal to or lower than SYNC_ERRBITS_ALLOWED.  
PIN_MODE[1:0]  
1
R/W  
Selects between un-buffered mode, buffered mode or test mode.  
The pin configuration is set according to Table 15.  
0: Un-buffered mode  
1: Buffered mode  
2: HSSD test mode  
3: Unused  
10  
PACKET_MODE  
1
R/W  
When this bit is set the packet mode is enabled. The pin  
configuration is set according to Table 15.  
In TX, this enables preamble generation, sync word, and CRC  
appending (if enabled by CRC_ON) in the buffered mode.  
In RX, this enables sync word detection in buffered and un-  
buffered modes, and CRC verification (if enabled by CRC_ON) in  
buffered mode.  
9:7  
6:5  
PRE_BYTES[2:0]  
3
3
R/W  
R/W  
The number of preamble bytes ("01010101") to be sent in packet  
mode:  
000: 0  
100: 8  
001: 1  
010: 2  
011: 4  
101: 16 110: 32 111: Infinitely on  
SYNC_WORD_SIZE[1:0]  
The size of the packet mode sync word sent in TX and correlated  
against in RX:  
00: The 8 MSB bits of SYNC_WORD.  
01: The 16 MSB bits of SYNC_WORD.  
10: The 24 MSB bits of SYNC_WORD.  
11: The 32 MSB bits of SYNC_WORD.  
4
CRC_ON  
1
R/W  
In packet mode a CRC is calculated and is transmitted after the  
data in TX, and a CRC is calculated during reception in RX.  
SWRS042A  
Page 72 of 83  
CC2400  
Bit  
3:2  
Field Name  
Reset  
R/W  
Description  
DATA_FORMAT[1:0]  
0
R/W  
Selects line-coding format used during RX and TX operations.  
00: NRZ  
01: Manchester  
10: 8/10 line-coding (Not applied to preambles or sync words)  
11: Reserved  
1
0
MODULATION_FORMAT  
TX_GAUSSIAN_FILTER  
0
1
R/W  
R/W  
Modulation format of modem:  
0: FSK/GFSK  
1: Reserved  
When this bit is set the data sent in TX is Gaussian filtered  
before transmission enabling GFSK  
GRDEC (0x21) - Generic Radio Decimation Control and Status  
Bit  
15:13  
12  
Field Name  
Reset  
R/W  
W0  
R
Description  
-
0
-
Reserved, write as 0.  
IND_SATURATION  
Signal indicates whether the accumulate-and-dump decimation  
filters have saturated at some point since the last read. If  
saturation occurs the DEC_SHIFTcan be adjusted. The status  
flag is cleared when reading the GRDECregister.  
11:10  
DEC_SHIFT[1:0]  
0
R/W  
Controls extra shifts in decimation, for extra precision.  
Decimation shift value:  
2: -2  
3: -1  
0: 0  
1: 1  
9:8  
7:0  
CHANNEL_DEC[1:0]  
0
0
R/W  
R/W  
Selects channel filter bandwidth.  
00: 1 MHz (used for 1Mbps and 250 kbps datarates)  
01: 500 kHz (used for 10 kbps data rate)  
01: 250 kHz  
11: 125 kHz  
DEC_VAL[7:0]  
In combination with CHANNEL_DEC[1:0], DEC_VAL[7:0]is  
used to program the data rate. See page 40 for a description.  
PKTSTATUS (0x22) - Packet Mode Status  
Bit  
15:11  
10  
Field Name  
Reset  
R/W  
W0  
R
Description  
-
0
0
Reserved, write as 0.  
SYNC_WORD_RECEIVED  
Indicates that the currently configured sync word has been  
received since RX was turned on.  
9
CRC_OK  
-
R
Indicates that the two next bytes available to be read from the  
FIFO equal the CRC16 calculated over the bytes already read  
from the FIFO.  
8
-
-
0
-
R
R
Reserved for future use.  
Reserved for future use.  
7:0  
SWRS042A  
Page 73 of 83  
CC2400  
INT (0x23) - Interrupt Register  
Bit  
15:8  
7
Field Name  
Reset  
0
R/W  
W0  
Description  
-
Reserved, write as 0.  
Reserved.  
-
0
R/W  
R/W  
R/W  
R/W  
6
PKT_POLARITY  
FIFO_POLARITY  
FIFO_THRESHOLD[4:0]  
0
Polarity of the PKT signal.  
5
0
Polarity of the FIFO signal. See Figure 10 for details.  
4:0  
30  
The FIFO pin signals that the 32 bytes data FIFO is near empty  
in TX or near full in RX. The threshold is used as follows:  
# bytes in FIFO >= FIFO_THRESHOLDin RX  
# bytes in FIFO <= 32 - FIFO_THRESHOLDin TX.  
Reserved (0x24) – Reserved regiser  
Bit  
15:14  
13:10  
9:7  
Field Name  
RES[15:14]  
RES[13:10]  
RES[9:7]  
Reset  
0
R/W  
W0  
Description  
Reserved for future use.  
Reserved for future use.  
Reserved for future use.  
Reserved for future use.  
8
R/W  
R/W  
R/W  
0
6:0  
RES[6:0]  
80  
Reserved (0x25) – Reserved register  
Bit  
15:12  
11:0  
Field Name  
RES[15:12]  
RES[11:0]  
Reset  
R/W  
W0  
Description  
0
0
Reserved for future use.  
Reserved for future use.  
R/W  
Reserved (0x26) – Reserved register  
Bit  
15:10  
9:0  
Field Name  
RES[15:10]  
RES[9:0]  
Reset  
R/W  
R/W  
R/W  
Description  
8
0
Reserved for future use.  
Reserved for future use.  
Reserved (0x27) – Reserved register  
Bit  
15:8  
7:3  
Field Name  
RES[15:8]  
RES[7:3]  
RES[2:0]  
Reset  
R/W  
R
Description  
-
0
6
Reserved for future use.  
Reserved for future use.  
Reserved for future use.  
R/W  
R/W  
2:0  
Reserved (0x28) – Reserved register  
Bit  
Field Name  
RES[15]  
Reset  
0
R/W  
R/W  
R/W  
R/W  
Description  
15  
Reserved for future use.  
Reserved for future use.  
Reserved for future use.  
14:13  
12:7  
RES[14:13]  
RES[12:7]  
2
63  
SWRS042A  
Page 74 of 83  
CC2400  
Bit  
6:0  
Field Name  
Reset  
R/W  
Description  
RES[6:0]  
0
R/W  
Reserved for future use.  
Reserved (0x29) – Reserved Register  
Bit  
15:8  
7:3  
Field Name  
RES[15:8]  
RES[7:3]  
RES[2:0]  
Reset  
R/W  
W0  
Description  
0
0
3
Reserved for future use.  
Reserved for future use.  
Reserved for future use.  
R/W  
R/W  
2:0  
Reserved (0x2A) – Reserved Register  
Bit  
15:11  
10  
Field Name  
RES[15:11]  
RES[10]  
Reset  
0
R/W  
W0  
Description  
Reserved for future use.  
Reserved for future use.  
Reserved for future use.  
0
R/W  
R/W  
9:0  
RES[9:0]  
512  
Reserved (0x2B) – Reserved register  
Bit  
15:14  
13  
Field Name  
RES[15:14]  
RES[13]  
Reset  
R/W  
W0  
R/W  
R
Description  
0
Reserved for future use.  
Reserved for future use.  
Reserved for future use.  
Reserved for future use.  
-
12  
RES[12]  
-
11:0  
RES[11:0]  
1953  
R
SYNCL (0x2C) - Sync Word, Lower 16 Bit  
Bit  
Field Name  
Reset  
R/W  
Description  
15:0  
SYNCWORD[15:0]  
0XDA26  
R/W  
Synchronisation word, lower 16 bit.  
The default synchronization word of 0XD391DA26has very  
good DC, autocorrelation, and bit-run properties for all  
synchronization word lengths.  
SYNCH (0x2D) - Sync Word, Upper 16 Bit  
Bit  
Field Name  
Reset  
R/W  
Description  
15:0  
SYNCWORD[31:16]  
0XD391  
R/W  
Synchronisation word, upper 16 bit.  
SWRS042A  
Page 75 of 83  
CC2400  
50 Package Description (QFN48)  
Note: The figure is an illustration only and not to scale.  
Quad Flat Pack - No Lead Package (QFN)  
A
A1  
b
D
E
D1  
E1  
e
L
L1  
L2  
QFN 48 Min  
Max  
0.8  
0.18  
0.25  
0.30  
5.04  
5.04  
0.43  
0.53  
0.63  
0.30  
0.40  
0.50  
0.203  
7.0  
7.0  
0.5  
1.0  
5.24  
5.24  
0.1  
The overall package height is 0.9 +/ 0.1 mm.  
All dimensions in mm  
The package is compliant to JEDEC standard MO-220.  
SWRS042A  
Page 76 of 83  
CC2400  
51 Recommended layout for package (QFN48)  
Note: The figure is an illustration only and not to scale. There are nine 14 mil diameter via  
holes distributed symmetrically in the ground pad under the package. See also the  
CC2400EM reference design.  
52 Package Thermal Properties  
Thermal resistance  
Air velocity [m/s]  
Rth,j-a [K/W]  
0
25.6  
53 Soldering Information  
Recommended soldering profile for both standard leaded packages and Pb-free packages is  
according to IPC/JEDEC J-STD-020B, July 2002.  
SWRS042A  
Page 77 of 83  
CC2400  
54 IC marking  
Note: Please submit the entire marking information when contacting Chipcon technical  
support about chip-related issues, not just the date code.  
Example of QFN 48 standard leaded assembly  
0440XAA  
0440 is assembly year and week no.  
XAA is lot code  
SWRS042A  
Page 78 of 83  
CC2400  
Example of QFN 48 RoHS compliant Pb-free assembly  
A440XAA  
A is to identify RoHS compliant Pb-free assembly  
4 is to identify year 2004  
40 is week no  
XAA is lot code  
SWRS042A  
Page 79 of 83  
CC2400  
55 Plastic Tube Specification  
QFN 7x7 mm antistatic tube.  
Tube Specification  
Package  
QFN 48  
Tube Width  
8.5 ± 0.2 mm  
Tube Height  
2.2 +0.2/-0.1  
mm  
Tube Length  
315 ± 1.25 mm  
Units per Tube  
43  
56 Carrier Tape and Reel Specification  
Carrier tape and reel is in accordance with EIA Specification 481.  
Tape and Reel Specification  
Package  
QFN 48  
Tape Width Component  
Pitch  
Hole  
Pitch  
4 mm  
Reel  
Diameter  
13 inch  
Units per Reel  
4000  
16 mm  
12 mm  
57 Ordering Information  
Ordering part number  
Description  
MOQ  
1170  
CC2400-STB1  
CC2400, QFN48 package, standard leaded assembly, tubes with  
43 pcs per tube, 2.4 GHz RF transceiver.  
43  
1096  
CC2400-STR1  
CC2400, QFN48 package, standard leaded assembly, T&R with  
4000 pcs per reel, 2.4 GHz RF transceiver.  
4,000  
43  
1139  
CC2400-RTB1  
CC2400, QFN48 package, RoHS compliant Pb-free assembly,  
tubes with 43 pcs per tube, 2.4 GHz RF transceiver.  
1140  
CC2400-RTR1  
CC2400, QFN48 package, RoHS compliant Pb-free assembly,with  
4000/T&R per reel, 2.4 GHz RF transceiver.  
4,000  
10031  
10041  
CC2400DK  
CC2400DK Development kit  
1
1
CC2400DBK, Demonstration Board Kit  
CC2400DBK  
1097  
1162  
1
1
CC2400 QFN48 package, standard leaded assembly, (5 pcs.)  
CC2400SK  
CC2400 QFN48 package, RoHS compliant Pb-free assembly, 5  
pcs.  
CC2400SK RoHS  
MOQ = Minimum Order Quantity  
T&R = tape and reel  
SWRS042A  
Page 80 of 83  
CC2400  
58 General Information  
58.1 Document History  
Revision  
Date  
2006-03-20  
2006-01-16  
Description/Changes  
1.5  
1.4  
Removed QLP information  
Address information and ordering information have  
been updated.  
1.3  
2004-10-20  
Various clarifications.  
Added recommended PCB footprint.  
Added package height.  
Added radio control state diagram with state ID  
numbers.  
Added information about EN 300 328 and EN 300  
440.  
Added AFC, RSSI settling time and 20 dB bandwidth  
to electrical specifications.  
Electrical specifications updated.  
Bit 5 of the STATUS register has been set as  
reserved; see Errata Note 003 for details.  
RSSI and carrier sense value calculation clarified and  
corrected.  
Added graphs showing typical current consumption,  
sensitivity and output power as function of  
temperature  
Clarified packet handling and data buffering sections.  
Description of the FSMTCregister corrected.  
Added example calculation to AFC description.  
Updated ordering information with RoHS-compliant  
Pb-free versions.  
“CRC-16” replaced with “CRC”.  
Reorganized electrical specification section.  
Added chapter numbering.  
Added QFN 48 package description.  
Added IC marking description.  
RSSI value calculation corrected.  
Various clarifications.  
Single-ended operation of the chip has been  
removed.  
1.2  
2004-02-05  
Corrected value of DEC_VALfor 250 kbps data rate.  
Added information that the core supply cannot be  
switched off while I/O supply is still on.  
Electrical specification updated.  
Selectivity in-band is now measured using a FSK  
modulated interferer.  
Added note that choice of crystal package strongly  
affects price.  
Added section about low-latency systems.  
Added graph of sensitivity vs. frequency offset.  
Added plot of modulated spectrum.  
Added more information about AFC.  
Added information about using an external PA.  
Operating conditions put into separate table.  
Removed 32 kHz oscillator.  
1.1  
1.0  
2003-10-02  
2003-09-10  
Added L71 to application circuit.  
Modified component names in application circuit to  
match reference design.  
Corrected E2 and D2 package dimensions.  
Minor corrections and editorial changes.  
Added recommendation on length of preamble when  
using GFSK.  
Added Manchester data encoding.  
Initial release.  
SWRS042A  
Page 81 of 83  
CC2400  
58.2 Product Status Definitions  
Data Sheet Identification  
Product Status  
Definition  
Advance Information  
Planned or Under  
This data sheet contains the design specifications for  
product development. Specifications may change in  
any manner without notice.  
Development  
Preliminary  
Engineering Samples This data sheet contains preliminary data, and  
and First Production  
supplementary data will be published at a later date.  
Chipcon reserves the right to make changes at any  
time without notice in order to improve design and  
supply the best possible product.  
This data sheet contains the final specifications.  
Chipcon reserves the right to make changes at any  
time without notice in order to improve design and  
supply the best possible product.  
No Identification Noted  
Obsolete  
Full Production  
Not In Production  
This data sheet contains specifications on a product  
that has been discontinued by Chipcon. The data  
sheet is printed for reference information only.  
58.3 Disclaimer  
Chipcon AS believes the information contained herein is correct and accurate at the time of this printing. However,  
Chipcon AS reserves the right to make changes to this product without notice. Chipcon AS does not assume any  
responsibility for the use of the described product; neither does it convey any license under its patent rights, or the  
rights of others. The latest updates are available at the Chipcon website or by contacting Chipcon directly.  
As far as possible, major changes of product specifications and functionality, will be stated in product specific Errata  
Notes published at the Chipcon website. Customers are encouraged to sign up to the Developers Newsletter for the  
most recent updates on products and support tools.  
When a product is discontinued this will be done according to Chipcon’s procedure for obsolete products as  
described in Chipcon’s Quality Manual. This includes informing about last-time-buy options. The Quality Manual can  
be downloaded from Chipcon’s website.  
Compliance with regulations is dependent on complete system performance. It is the customer’s responsibility to  
ensure that the system complies with regulations.  
58.4 Trademarks  
SmartRF is a registered trademark of Chipcon AS. SmartRF is Chipcon's RF technology platform with  
RF library cells, modules and design expertise. Based on SmartRF technology Chipcon develops  
standard component RF circuits as well as full custom ASICs based on customer requirements and this  
technology.  
All other trademarks, registered trademarks and product names are the sole property of their respective  
owners.  
58.5 Life Support Policy  
This Chipcon product is not designed for use in life support appliances, devices, or other systems where  
malfunction can reasonably be expected to result in significant personal injury to the user, or as a critical  
component in any life support device or system whose failure to perform can be reasonably expected to  
cause the failure of the life support device or system, or to affect its safety or effectiveness. Chipcon AS  
customers using or selling these products for use in such applications do so at their own risk and agree to  
fully indemnify Chipcon AS for any damages resulting from any improper use or sale.  
© 2003, 2004, 2005, 2006 Chipcon AS. All rights reserved.  
SWRS042A  
Page 82 of 83  
IMPORTANT NOTICE  
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,  
enhancements, improvements, and other changes to its products and services at any time and to discontinue  
any product or service without notice. Customers should obtain the latest relevant information before placing  
orders and should verify that such information is current and complete. All products are sold subject to TI’s terms  
and conditions of sale supplied at the time of order acknowledgment.  
TI warrants performance of its hardware products to the specifications applicable at the time of sale in  
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI  
deems necessary to support this warranty. Except where mandated by government requirements, testing of all  
parameters of each product is not necessarily performed.  
TI assumes no liability for applications assistance or customer product design. Customers are responsible for  
their products and applications using TI components. To minimize the risks associated with customer products  
and applications, customers should provide adequate design and operating safeguards.  
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,  
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process  
in which TI products or services are used. Information published by TI regarding third-party products or services  
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.  
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