ADRF6755ACPZ-R7 [ADI]
100 MHz to 2400 MHz I/Q Modulator with Integrated Fractional-N PLL and VCO;型号: | ADRF6755ACPZ-R7 |
厂家: | ADI |
描述: | 100 MHz to 2400 MHz I/Q Modulator with Integrated Fractional-N PLL and VCO |
文件: | 总48页 (文件大小:2098K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
100 MHz to 2400 MHz I/Q Modulator
with Integrated Fractional-N PLL and VCO
Data Sheet
ADRF6755
FEATURES
GENERAL DESCRIPTION
I/Q modulator with integrated fractional-N PLL and VCO
Gain control span: 47 dB in 1 dB steps
The ADRF6755 is a highly integrated quadrature modulator,
frequency synthesizer, and programmable attenuator. The device
covers an operating frequency range from 100 MHz to 2400 MHz
for use in satellite, cellular, and broadband communications.
Output frequency range: 100 MHz to 2400 MHz
Output 1 dB compression: 8 dBm at LO = 1800 MHz
Output IP3: 20.5 dBm at LO = 1800 MHz
Noise floor: −161 dBm/Hz at LO = 1800 MHz
Baseband modulation bandwidth: 600 MHz (3 dB)
Output frequency resolution: 1 Hz
The ADRF6755 modulator includes a high modulus, fractional-N
frequency synthesizer with integrated VCO, providing less than
1 Hz frequency resolution, and a 47 dB digitally controlled output
attenuator with 1 dB steps.
SPI and I2C-compatible serial interfaces
Power supply: 5 V/380 mA
Control of all the on-chip registers is through a user-selected SPI
interface or I2C interface. The device operates from a single power
supply ranging from 4.75 V to 5.25 V.
VCC1
VCC2
VCC3
VCC4
LOMON
LOMON
3.3V
REGULATOR
REGOUT
IBB
IBB
VREG1
VREG2
VREG3
VREG4
VREG5
VREG6
CCOMP1
CCOMP2
CCOMP3
47dB
GAINCONTROL
RANGE
RFDIVIDER
0°/90°
RFOUT
VCO
CORE
VTUNE
TXDIS
QBB
QBB
RSET
REFERENCE
×2
5-BIT
DIVIDER
REFIN
REFIN
÷2
+
PHASE
DOUBLER
CHARGE
PUMP
FREQUENCY
DETECTOR
CP
–
NC
CURRENT SETTING
CR9[7:4]
N-COUNTER
NC
THIRD-ORDER
FRACTIONAL
INTERPOLATOR
LDET
SDI/SDA
CLK/SCL
SDO
2
SPI/I C
INTERFACE
CS
FRACTIONAL
REGISTER
MODULUS
INTEGER
REGISTER
25
2
ADRF6755
AGND
DGND
Figure 1.
Rev. B
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responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rightsof third parties that may result fromits use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks andregisteredtrademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700 ©2012–2013 Analog Devices, Inc. All rights reserved.
Technical Support
www.analog.com
ADRF6755
Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
SPI Interface................................................................................ 27
Program Modes .......................................................................... 29
Register Map ................................................................................... 31
Register Map Summary ............................................................. 31
Register Bit Descriptions........................................................... 32
Suggested Power-Up Sequence..................................................... 35
Initial Register Write Sequence ................................................ 35
Evaluation Board ............................................................................ 37
General Description................................................................... 37
Hardware Description ............................................................... 37
PCB Artwork............................................................................... 41
Bill of Materials........................................................................... 44
Outline Dimensions....................................................................... 45
Ordering Guide .......................................................................... 45
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Timing Characteristics ................................................................ 8
Absolute Maximum Ratings.......................................................... 10
ESD Caution................................................................................ 10
Pin Configuration and Function Descriptions........................... 11
Typical Performance Characteristics ........................................... 13
Theory of Operation ...................................................................... 21
Overview...................................................................................... 21
PLL Synthesizer and VCO......................................................... 21
Quadrature Modulator .............................................................. 24
Attenuator.................................................................................... 25
Voltage Regulator ....................................................................... 25
I2C Interface ................................................................................ 25
REVISION HISTORY
4/13—Rev. A to Rev. B
Changes to Ordering Guide .......................................................... 45
11/12—Rev. 0 to Rev. A
Changes to Figure 1.......................................................................... 1
Changes to Input Frequency Parameter, Table 1.......................... 6
Changes to Bit 7 Description, Table 27 and Bit 6 Description,
Table 27 ............................................................................................ 34
Changed 0x00 to 0x60 in Step 13 ................................................. 35
Updated Outline Dimensions....................................................... 45
Changes to Ordering Guide .......................................................... 45
7/12—Revision 0: Initial Version
Rev. B | Page 2 of 48
Data Sheet
ADRF6755
SPECIFICATIONS
VCC = 5 V 5%, operating temperature range = −40°C to +85°C, I/Q inputs = 0.9 V p-p differential sine waves in quadrature on a 500 mV dc
bias, REFIN = 80 MHz, PFD = 40 MHz, baseband frequency = 1 MHz, LOMON off, loop bandwidth (LBW) = 100 kHz, ICP = 5 mA, unless
otherwise noted.
Table 1.
Parameter
Test Conditions/Comments
Min
Typ
Max
Unit
OPERATING FREQUENCY RANGE
RF OUTPUT = 100 MHz
Nominal Output Power
Gain Flatness
100
2400
MHz
RFOUT pin
VIQ = 0.9 V p-p differential
Any 40 MHz
−0.2
2.0
dBm
dB
Output P1dB
9.0
dBm
Output IP3
f1BB = 3.5 MHz, f2BB = 4.5 MHz, POUT = −6 dBm per tone
Attenuator setting = 0 dB
Attenuator setting = 0 dB to 47 dB
Attenuator setting = 0 dB to 47 dB
21.0
−12
−55
−80
−70
−153
−60
−85
dBm
dB
dBc
dBm
dBc
dBm/Hz
dBc
dBc
dBc
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
° rms
Output Return Loss
LO Carrier Feedthrough1
2× LO Carrier Feedthrough
Sideband Suppression
Noise Floor
I/Q inputs = 0 V p-p differential, attenuator setting = 0 dB
Baseband Harmonics
Synthesizer Spurs
Integer boundary < loop bandwidth
>10 MHz offset from carrier
100 Hz offset
1 kHz offset
10 kHz offset
100 kHz offset
1 MHz offset
10 MHz offset
1 kHz to 8 MHz integration bandwidth
−90
Phase Noise
−106
−116
−127
−131
−146
−152
0.02
Integrated Phase Noise
RF OUTPUT = 300 MHz
Nominal Output Power
Gain Flatness
RFOUT pin
VIQ = 0.9 V p-p differential
Any 40 MHz
0.2
0.5
dBm
dB
Output P1dB
9.3
dBm
Output IP3
f1BB = 3.5 MHz, f2BB = 4.5 MHz, POUT = −6 dBm per tone
Attenuator setting = 0 dB
Attenuator setting = 0 dB to 47 dB
Attenuator setting = 0 dB to 47 dB
23.0
−20
−50
−75
−70
−158
−60
−85
−85
−105
−113
−117
−122
−145
−150
0.04
dBm
dB
dBc
dBm
dBc
dBm/Hz
dBc
dBc
dBc
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
° rms
Output Return Loss
LO Carrier Feedthrough1
2× LO Carrier Feedthrough
Sideband Suppression
Noise Floor
I/Q inputs = 0 V p-p differential, attenuator setting = 0 dB
Baseband Harmonics
Synthesizer Spurs
Integer boundary < loop bandwidth
>10 MHz offset from carrier
100 Hz offset
1 kHz offset
10 kHz offset
100 kHz offset
1 MHz offset
10 MHz offset
1 kHz to 8 MHz integration bandwidth
Phase Noise
Integrated Phase Noise
Rev. B | Page 3 of 48
ADRF6755
Data Sheet
Parameter
Test Conditions/Comments
RFOUT pin
VIQ = 0.9 V p-p differential
Any 40 MHz
Min
Typ
Max
Unit
RF OUTPUT = 700 MHz
Nominal Output Power
Gain Flatness
0.2
0.5
dBm
dB
Output P1dB
9.4
dBm
Output IP3
f1BB = 3.5 MHz, f2BB = 4.5 MHz, POUT = −6 dBm per tone
Attenuator setting = 0 dB
Attenuator setting = 0 dB to 47 dB
Attenuator setting = 0 dB to 47 dB
23.0
−16
−48
−70
−70
−158
−60
−60
−85
−97
−106
−112
−115
−139
−154
0.07
dBm
dB
dBc
dBm
dBc
dBm/Hz
dBc
dBc
dBc
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
° rms
Output Return Loss
LO Carrier Feedthrough1
2× LO Carrier Feedthrough
Sideband Suppression
Noise Floor
I/Q inputs = 0 V p-p differential, attenuator setting = 0 dB
Baseband Harmonics
Synthesizer Spurs
Integer boundary < loop bandwidth
>10 MHz offset from carrier
100 Hz offset
1 kHz offset
10 kHz offset
100 kHz offset
1 MHz offset
10 MHz offset
1 kHz to 8 MHz integration bandwidth
Phase Noise
Integrated Phase Noise
RF OUTPUT = 900 MHz
Nominal Output Power
Gain Flatness
RFOUT pin
VIQ = 0.9 V p-p differential
Any 40 MHz
0.0
0.5
dBm
dB
Output P1dB
9.2
dBm
Output IP3
f1BB = 3.5 MHz, f2BB = 4.5 MHz, POUT = −6 dBm per tone
Attenuator setting = 0 dB
Attenuator setting = 0 dB to 47 dB
Attenuator setting = 0 dB to 47 dB
22.8
−15
−48
−68
−60
−158.5
−152
−171
−60
−60
−80
dBm
dB
dBc
dBm
Output Return Loss
LO Carrier Feedthrough1
2× LO Carrier Feedthrough
Sideband Suppression
Noise Floor
dBc
I/Q inputs = 0 V p-p differential, attenuator setting = 0 dB
Attenuator setting = 0 dB to 21 dB, carrier offset = 10 MHz
Attenuator setting = 21 dB to 47 dB, carrier offset = 10 MHz
dBm/Hz
dBc/Hz
dBm/Hz
dBc
dBc
dBc
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
° rms
Baseband Harmonics
Synthesizer Spurs
Integer boundary < loop bandwidth
>10 MHz offset from carrier
100 Hz offset
1 kHz offset
10 kHz offset
100 kHz offset
1 MHz offset
10 MHz offset
1 kHz to 8 MHz integration bandwidth
Phase Noise
−94
−104
−109
−114
−139
−154
0.11
Integrated Phase Noise
RF OUTPUT = 1800 MHz
Nominal Output Power
Gain Flatness
RFOUT pin
VIQ = 0.9 V p-p differential
Any 40 MHz
−0.4
0.5
dBm
dB
Output P1dB
Output IP3
Output Return Loss
LO Carrier Feedthrough1
2× LO Carrier Feedthrough
Sideband Suppression
8.0
dBm
dBm
dB
dBc
dBm
dBc
f1BB = 3.5 MHz, f2BB = 4.5 MHz, POUT = −6 dBm per tone
Attenuator setting = 0 dB
Attenuator setting = 0 dB to 47 dB
Attenuator setting = 0 dB to 47 dB
20.5
−13
−45
−53
−45
Rev. B | Page 4 of 48
Data Sheet
ADRF6755
Parameter
Test Conditions/Comments
Min
Typ
Max
Unit
Noise Floor
I/Q inputs = 0 V p-p differential, attenuator setting = 0 dB
Attenuator setting = 0 dB to 21 dB, carrier offset = 10 MHz
Attenuator setting = 21 dB to 47 dB, carrier offset = 10 MHz
−161
−150
−170
−58
−60
−75
dBm/Hz
dBc/Hz
dBm/Hz
dBc
dBc
dBc
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
° rms
Baseband Harmonics
Synthesizer Spurs
Integer boundary < loop bandwidth
>10 MHz offset from carrier
100 Hz offset
1 kHz offset
10 kHz offset
100 kHz offset
1 MHz offset
10 MHz offset
1 kHz to 8 MHz integration bandwidth
Phase Noise
−89
−99
−103
−108
−133
−152
0.17
Integrated Phase Noise
RF OUTPUT = 1875 MHz
Nominal Output Power
Gain Flatness
RFOUT pin
VIQ = 0.9 V p-p differential
Any 40 MHz
−0.6
0.5
dBm
dB
Output P1dB
7.8
dBm
Output IP3
f1BB = 3.5 MHz, f2BB = 4.5 MHz, POUT = −6 dBm per tone
Attenuator setting = 0 dB
Attenuator setting = 0 dB to 47 dB
Attenuator setting = 0 dB to 47 dB
20.2
−13
−45
−52
−50
−160
−150
−170
−60
−60
−73
−89
−97
−103
−108
−133
−152
0.18
dBm
dB
dBc
dBm
Output Return Loss
LO Carrier Feedthrough1
2× LO Carrier Feedthrough
Sideband Suppression
Noise Floor
dBc
I/Q inputs = 0 V p-p differential, attenuator setting = 0 dB
Attenuator setting = 0 dB to 21 dB, carrier offset = 10 MHz
Attenuator setting = 21 dB to 47 dB, carrier offset = 10 MHz
dBm/Hz
dBc/Hz
dBm/Hz
dBc
dBc
dBc
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
° rms
Baseband Harmonics
Synthesizer Spurs
Integer boundary < loop bandwidth
>10 MHz offset from carrier
100 Hz offset
1 kHz offset
10 kHz offset
100 kHz offset
1 MHz offset
10 MHz offset
1 kHz to 8 MHz integration bandwidth
Phase Noise
Integrated Phase Noise
RF OUTPUT = 2100 MHz
Nominal Output Power
Gain Flatness
RFOUT pin
VIQ = 0.9 V p-p differential
Any 40 MHz
−1.0
0.5
dBm
dB
Output P1dB
Output IP3
7.4
dBm
dBm
dB
dBc
dBm
dBc
dBm/Hz
dBc/Hz
dBm/Hz
dBc
dBc
dBc
f1BB = 3.5 MHz, f2BB = 4.5 MHz, POUT = −6 dBm per tone
Attenuator setting = 0 dB
Attenuator setting = 0 dB to 47 dB
Attenuator setting = 0 dB to 47 dB
19.5
−12
−44
−51
−45
−161
−149
−170
−60
−60
−67
Output Return Loss
LO Carrier Feedthrough1
2× LO Carrier Feedthrough
Sideband Suppression
Noise Floor
I/Q inputs = 0 V p-p differential, attenuator setting = 0 dB
Attenuator setting = 0 dB to 21 dB, carrier offset = 10 MHz
Attenuator setting = 21 dB to 47 dB, carrier offset = 10 MHz
Baseband Harmonics
Synthesizer Spurs
Integer boundary < loop bandwidth
>10 MHz offset from carrier
Rev. B | Page 5 of 48
ADRF6755
Data Sheet
Parameter
Test Conditions/Comments
100 Hz offset
1 kHz offset
10 kHz offset
100 kHz offset
1 MHz offset
10 MHz offset
1 kHz to 8 MHz integration bandwidth
Min
Typ
Max
Unit
Phase Noise
−88
−98
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
° rms
−101
−108
−134
−152
0.25
Integrated Phase Noise
RF OUTPUT = 2400 MHz
Nominal Output Power
Gain Flatness
RFOUT pin
VIQ = 0.9 V p-p differential
Any 40 MHz
−1.7
0.5
dBm
dB
Output P1dB
6.5
dBm
Output IP3
f1BB = 3.5 MHz, f2BB = 4.5 MHz, POUT = −6 dBm per tone
Attenuator setting = 0 dB
Attenuator setting = 0 dB to 47 dB
Attenuator setting = 0 dB to 47 dB
18.5
−11
−43
−60
−40
−160.5
−148
−170
−55
−55
−64
dBm
dB
dBc
dBm
Output Return Loss
LO Carrier Feedthrough1
2× LO Carrier Feedthrough
Sideband Suppression
Noise Floor
dBc
I/Q inputs = 0 V p-p differential, attenuator setting = 0 dB
Attenuator setting = 0 dB to 21 dB, carrier offset = 10 MHz
Attenuator setting = 21 dB to 47 dB, carrier offset = 10 MHz
dBm/Hz
dBc/Hz
dBm/Hz
dBc
dBc
dBc
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
dBc/Hz
° rms
Baseband Harmonics
Synthesizer Spurs
Integer boundary < loop bandwidth
>10 MHz offset from carrier
100 Hz offset
1 kHz offset
10 kHz offset
100 kHz offset
1 MHz offset
10 MHz offset
1 kHz to 8 MHz integration bandwidth
Phase Noise
−85
−96
−100
−107
−132
−152
0.25
Integrated Phase Noise
REFERENCE CHARACTERISTICS
Input Frequency
REFIN pin
With reference divide-by-2 enabled
With reference divide-by-2 disabled
With reference doubler enabled
AC-coupled
10
10
10
0.4
300
165
80
VREG
10
MHz
MHz
MHz
V p-p
pF
Input Sensitivity
Input Capacitance
Input Current
CHARGE PUMP
ICP Sink/Source
High Value
Low Value
Absolute Accuracy
VCO
100
µA
Programmable, RSET = 4.7 kΩ
5
mA
µA
%
312.5
4.0
Gain
KVCO
25
MHz/V
SYNTHESIZER
Frequency Resolution
Frequency Settling
Maximum Frequency Step for
No Autocalibration
LO = 100 MHz to 2400 MHz
1
Hz
ms
Any step size, maximum frequency error = 100 Hz
Frequency step with no autocalibration routine;
Register CR24, Bit 0 = 1
0.17
100/2RFDIV kHz
Phase Detector Frequency
10
40
MHz
Rev. B | Page 6 of 48
Data Sheet
ADRF6755
Parameter
Test Conditions/Comments
Min
Typ
Max
Unit
GAIN CONTROL
Gain Range
Step Size
47
1
0.3
dB
dB
dB
Relative Step Accuracy
Fixed frequency, adjacent steps, all attenuation steps,
LO > 300 MHz2
Over full frequency range, adjacent steps, all attenuation
1.5
dB
steps, LO > 300 MHz3
Absolute Step Accuracy4
Output Settling Time
OUTPUT DISABLE
47 dB attenuation step, LO > 300 MHz5
Any step; output power settled to 0.2 dB
TXDIS pin
−2.0
15
dB
µs
Off Isolation
RFOUT, attenuator setting = 0 dB to 47 dB, TXDIS high
LO, attenuator setting = 0 dB to 47 dB, TXDIS high
2× LO, attenuator setting = 0 dB to 47 dB, TXDIS high
TXDIS high to low: output power to 90% of envelope
Frequency settling to 100 Hz
−100
−75
−50
180
20
dBm
dBm
dBm
ns
Turn-On Settling Time
µs
Turn-Off Settling Time
MONITOR OUTPUT
TXDIS low to high (to −55 dBm)
350
ns
LOMON, LOMON pins
Nominal Output Power
BASEBAND INPUTS
−24
dBm
IBB, IBB, QBB, QBB pins
I and Q Input Bias Level
3 dB Bandwidth
500
600
mV
MHz
LOGIC INPUTS
Input High Voltage, VINH
Input Low Voltage, VINL
Input High Voltage, VINH
Input Low Voltage, VINL
Input Current, IINH/IINL
Input Capacitance, CIN
LOGIC OUTPUTS
CS, TXDIS pins
CS, TXDIS pins
SDI/SDA, CLK/SCL pins
SDI/SDA, CLK/SCL pins
CS, TXDIS, SDI/SDA, CLK/SCL pins
CS, TXDIS, SDI/SDA, CLK/SCL pins
1.4
2.1
V
V
V
V
µA
pF
0.6
1.1
1
10
Output High Voltage, VOH
Output Low Voltage, VOL
SDO, LDET pins; IOH = 500 μA
SDO, LDET pins; IOL = 500 μA
SDA (SDI/SDA); IOL = 3 mA
2.8
V
V
V
0.4
0.4
POWER SUPPLIES
VCC1, VCC2, VCC3, VCC4, VREG1, VREG2, VREG3, VREG4,
VREG5, VREG6, and REGOUT pins;
REGOUT normally connected to VREG1, VREG2, VREG3,
VREG4, VREG5, and VREG6
Voltage Range
VCC1, VCC2, VCC3, and VCC4
REGOUT, VREG1, VREG2, VREG3, VREG4, VREG5, and
VREG6
VCC1, VCC2, VCC3, and VCC4 combined; REGOUT con-
nected to VREG1, VREG2, VREG3, VREG4, VREG5, and
VREG6
CR29[0] = 0, power down modulator,
CR12[2] = 1, power down PLL,
4.75
5
3.3
5.25
420
V
V
Supply Current
380
7
mA
mA
Power-Down Current
CR28[4] = 1, power down RFDIVIDER,
CR27[2] = 0, power down LOMON
Operating Temperature
−40
+85
°C
1 LO carrier feedthrough is expressed in dBc relative to the RF output power changing as the attenuator is stepped. LO carrier feedthrough is constant as the RF output
is altered due to a change in the I/Q input amplitude.
2 For relative step accuracy at LO < 300 MHz, refer to Figure 37.
3 For relative step accuracy over frequency range at LO < 300 MHz, refer to Figure 39.
4 All other attenuation steps have an absolute error of < 2.0 dB.
5 For absolute step accuracy at LO < 300 MHz, refer to Figure 40.
Rev. B | Page 7 of 48
ADRF6755
Data Sheet
TIMING CHARACTERISTICS
I2C Interface Timing
Table 2.
Parameter1
Symbol
fSCL
tHIGH
Limit
400
600
1300
600
600
100
300
600
900
900
1300
Unit
SCL Clock Frequency
SCL Pulse Width High
SCL Pulse Width Low
Start Condition Hold Time
Start Condition Setup Time
Data Setup Time
Data Hold Time
Stop Condition Setup Time
Data Valid Time
kHz max
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns max
ns max
ns min
tLOW
tHD;STA
tSU;STA
tSU;DAT
tHD;DAT
tSU;STO
tVD;DAT
tVD;ACK
tBUF
Data Valid Acknowledge Time
Bus Free Time
1 See Figure 2.
tVD;DAT AND
tVD;ACK (ACK SIGNAL ONLY)
tSU;DAT
tBUF
SDA
tSU;STA
tSU;STO
tHD;STA
tLOW
SCL
S
S
P
S
1/fSCL
tHD;DAT
tHIGH
START
CONDITION
STOP
CONDITION
Figure 2. I2C Port Timing Diagram
Rev. B | Page 8 of 48
Data Sheet
ADRF6755
SPI Interface Timing
Table 3.
Parameter1
Symbol
Limit
20
15
15
5
10
5
5
Unit
CLK Frequency
fCLK
t1
t2
t3
t4
t5
t6
t7
t8
MHz max
ns min
ns min
ns min
ns min
ns min
ns min
ns min
ns max
CLK Pulse Width High
CLK Pulse Width Low
Start Condition Hold Time
Data Setup Time
Data Hold Time
Stop Condition Setup Time
SDO Access Time
15
25
CS to SDO High Impedance
1 See Figure 3.
t3
CS
t1
CLK
SDI
t6
t2
t4
t5
SDO
t7
t8
Figure 3. SPI Port Timing Diagram
Rev. B | Page 9 of 48
ADRF6755
Data Sheet
ABSOLUTE MAXIMUM RATINGS
Table 4.
Parameter
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Rating
VCC1, VCC2, VCC3, and VCC4 Supply Voltage −0.3 V to +6 V
VREG1, VREG2, VREG3, VREG4, VREG5, and
VREG6 Supply Voltage
−0.3 V to +4 V
IBB, IBB, QBB, and QBB
0 V to 2.5 V
Digital I/O
−0.3 V to +4 V
−0.3 V to +4 V
Analog I/O (Other Than IBB, IBB, QBB, and
QBB)
ESD CAUTION
Maximum Junction Temperature
Storage Temperature Range
125°C
−65°C to +150°C
Rev. B | Page 10 of 48
Data Sheet
ADRF6755
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
VCC4
IBB
1
2
3
4
5
6
7
8
9
PIN 1
INDICATOR
42 VCC3
41 VCC3
IBB
40 AGND
QBB
QBB
AGND
RSET
NC
CP
NC 10
VCC1 11
39 AGND
38 VTUNE
37 AGND
ADRF6755
36 VREG6
35 CCOMP3
34 CCOMP2
33 CCOMP1
32 DGND
TOP VIEW
(Not to Scale)
REGOUT 12
VREG1 13
VREG2 14
31 VREG5
30 CLK/SCL
29 SDI/SDA
NOTES
1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN.
2. CONNECT EXPOSED PAD TO GROUND PLANE VIA
A LOW IMPEDANCE PATH.
Figure 4. Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic
11, 55, 56, 41, 42, 1 VCC1 to VCC4
Description
Positive Power Supplies for I/Q Modulator. Apply a 5 V power supply to VCC1, which should be
decoupled with power supply decoupling capacitors. Connect VCC2, VCC3, and VCC4 to the same
5 V power supply.
12
REGOUT
3.3 V Output Supply. Drives VREG1, VREG2, VREG3, VREG4, VREG5, and VREG6.
13, 14, 15, 16, 31,
36
VREG1 to
VREG6
Positive Power Supplies for PLL Synthesizer, VCO, and Serial Port. Connect these pins to REGOUT
(3.3 V) and decouple them separately.
6, 19, 20, 21, 22, 23, AGND
24, 37, 39, 40, 46, 47,
Analog Ground. Connect to a low impedance ground plane.
49, 50, 51, 52, 53, 54
32
DGND
Digital Ground. Connect to the same low impedance ground plane as the AGND pins.
2, 3
IBB, IBB
Differential In-Phase Baseband Inputs. These high impedance inputs must be dc biased to approx-
imately 500 mV dc and should be driven from a low impedance source. Nominal characterized ac signal
swing is 450 mV p-p on each pin. These inputs are not self-biased and must be externally biased.
4, 5
QBB, QBB
Differential Quadrature Baseband Inputs. These high impedance inputs must be dc-biased to
approximately 500 mV dc and should be driven from a low impedance source. Nominal charac-
terized ac signal swing is 450 mV p-p on each pin. These inputs are not self-biased and must be
externally biased.
33, 34, 35
CCOMP1 to
CCOMP3
Internal Compensation Nodes. These pins must be decoupled to ground with a 100 nF capacitor.
38
7
VTUNE
Control Input to the VCO. This voltage determines the output frequency and is derived from
filtering the CP output voltage.
Charge Pump Current Set. Connecting a resistor between this pin and ground sets the maximum
charge pump output current. The relationship between ICP and RSET is as follows:
RSET
23.5
ICPmax
=
RSET
where RSET = 4.7 kΩ and ICP max = 5 mA.
9
CP
CS
Charge Pump Output. When enabled, this output provides ICP to the external loop filter, which, in
turn, drives the internal VCO.
Chip Select, CMOS Input. When CS is high, the data stored in the shift registers is loaded into one of
31 latches. In I2C mode, when CS is high, the slave address of the device is 0x60, and, when CS is
low, the slave address is 0x40.
27
Rev. B | Page 11 of 48
ADRF6755
Data Sheet
Pin No.
Mnemonic
Description
29
SDI/SDA
Serial Data Input for SPI Port/Serial Data Input/Output for I2C Port. In SPI mode, this pin is a high
impedance CMOS data input, and data is loaded in an 8-bit word. In I2C mode, this pin is a bidirec-
tional port.
30
CLK/SCL
Serial Clock Input for SPI/I2C Port. This serial clock is used to clock in the serial data to the registers.
This input is a high impedance CMOS input.
28
17
18
48
45
SDO
Serial Data Output for SPI Port. Register states can be read back on the SDO data output line.
Reference Input. This high impedance CMOS input should be ac-coupled.
Reference Input Bar. This pin should be either grounded or ac-coupled to ground.
RF Output. Single-ended, 50 Ω, internally biased RF output. This pin must be ac-coupled to the load.
Output Disable. This pin can be used to disable the RF output. Connect to a high logic level to
disable the output. Connect to a low logic level for normal operation.
REFIN
REFIN
RFOUT
TXDIS
25, 26
LOMON,
LOMON
Differential Monitor Outputs. These pins provide a replica of the internal local oscillator frequency
(1× LO) at four different power levels: −6 dBm, −12 dBm, −18 dBm, and −24 dBm, approximately.
These open-collector outputs must be terminated with external resistors to REGOUT. These outputs
can be disabled through serial port programming and should be tied to REGOUT if not used.
8, 10
44
NC
LDET
No Connect. Do not connect to these pins.
Lock Detect. This output pin indicates the state of the PLL: a high level indicates a locked condition,
whereas a low level indicates a loss of lock condition.
43
MUXOUT
EP
Mux Output. This pin is a test output for diagnostic use only. Do not connect to this pin.
Exposed Paddle. Connect to ground plane via a low impedance path.
Exposed Paddle
Rev. B | Page 12 of 48
Data Sheet
ADRF6755
TYPICAL PERFORMANCE CHARACTERISTICS
VCC = 5 V 5%, operating temperature range = −40°C to +85°C, I/Q inputs = 0.9 V p-p differential sine waves in quadrature on a 500 mV dc
bias, REFIN = 80 MHz, PFD = 40 MHz, baseband frequency = 1 MHz, LOMON is off, loop bandwidth (LBW) = 100 kHz, ICP = 5 mA,
unless otherwise noted. A nominal condition is defined as 25°C, 5.00 V, and an LO frequency of 1800 MHz. A worst-case condition is
defined as having the worst-case temperature, supply voltage, and LO frequency.
2
60
50
40
30
20
10
0
NOMINAL
WORST CASE
1
0
–1
–2
–3
–4
–5
25°C; 5V
85°C; 4.75V
85°C; 5.25V
–40°C; 4.75V
–40°C; 5.25V
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
–60
–55
–50
–45
–40
–35
–30
LO FREQUENCY (MHz)
SIDEBAND SUPPRESSION (dBc)
Figure 5. Output Power vs. LO Frequency, Supply, and Temperature
Figure 8. Sideband Suppression Distribution at Nominal and
Worst-Case Conditions
–30
25
NOMINAL
WORST CASE
–35
–40
–45
–50
–55
–60
–65
–70
–75
–80
20
15
10
5
0
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
–4.2 –3.8 –3.4 –3.0 –2.6 –2.2 –1.8 –1.4 –1.0 –0.6 –0.2 0.2 0.6 1.0
LO FREQUENCY (MHz)
OUTPUT POWER (dBm)
Figure 9. LO Carrier Feedthrough vs. LO Frequency, Attenuation,
Supply, and Temperature
Figure 6. Output Power Distribution at Nominal and
Worst-Case Conditions
80
0
NOMINAL
+25°C, 5.00V
WORST CASE
70
+85°C, 4.75V
–10
+85°C, 5.25V
–40°C, 4.75V
–20
–30
–40
–50
–60
–70
–80
–90
–100
–40°C, 5.25V
60
50
40
30
20
10
0
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
–60 –58 –56 –54 –52 –50 –48 –46 –44 –42 –40 –38 –36 –34 –32 –30
LO CARRIER FEEDTHROUGH (dBc)
LO FREQUENCY (MHz)
Figure 7. Sideband Suppression vs. LO Frequency, Supply, and Temperature
Figure 10. LO Carrier Feedthrough Distribution at Nominal and Worst-Case
Conditions and Attenuation Setting
Rev. B | Page 13 of 48
ADRF6755
Data Sheet
–40
45
40
35
30
25
20
15
10
5
NOMINAL
WORST CASE
–50
–60
–70
–80
–90
–100
–110
–120
ATTENUATION = 0dB
ATTENUATION = 12dB
ATTENUATION = 21dB
ATTENUATION = 33dB
ATTENUATION = 47dB
0
3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
LO FREQUENCY (MHz)
OUTPUT P1dB (dBm)
Figure 11. 2× LO Carrier Feedthrough vs. LO Frequency, Attenuation,
Supply, and Temperature
Figure 14. Output P1dB Compression Point Distribution at Nominal
and Worst-Case Conditions
10
1.0
30
28
26
24
22
20
18
16
14
12
5
0.5
1dB
COMPRESSION
POINT
0
0
–5
–0.5
–1.0
–1.5
–2.0
–2.5
–10
–15
–20
–25
10
0.1
1
10
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
DIFFERENTIAL INPUT VOLTAGE (V p-p)
LO FREQUENCY (MHz)
Figure 15. Output IP3 vs. LO Frequency at Nominal Conditions
Figure 12. Output P1dB Compression Point at Worst-Case LO Frequency
vs. Supply and Temperature
10.5
10.0
9.5
9.0
8.5
8.0
7.5
7.0
6.5
50
NOMINAL
WORST CASE
45
40
35
30
25
20
15
10
5
6.0
0
15
16
17
18
19
20
21
22
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
LO FREQUENCY (MHz)
OUTPUT IP3 (dBm)
Figure 13. Output P1dB Compression Point vs. LO Frequency at
Nominal Conditions
Figure 16. Output IP3 Distribution at Nominal and Worst-Case
Conditions
Rev. B | Page 14 of 48
Data Sheet
ADRF6755
–145
–147
–149
–151
–153
–155
–157
–159
–161
–163
–165
–60
ATTENUATION = 21dB
–70
ATTENUATION = 0dB
–80
–90
–100
–110
–120
ATTENUATION = 47dB
–130
–25
–20
–15
–10
–5
0
5
10
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
OUTPUT POWER (dBm)
LO FREQUENCY (MHz)
Figure 20. Noise Floor at 0 dB Attenuation vs. Output Power
at Nominal Conditions
Figure 17. LO Off Isolation vs. LO Frequency, Attenuation, Supply,
and Temperature
–30
100
ATTENUATION
= 21dB (dBc/Hz)
–40
–50
90
80
70
60
50
40
30
20
10
0
ATTENUATION = 0dB
–60
ATTENUATION
= 0dB (dBc/Hz)
–70
–80
–90
ATTENUATION
= 21dB (dBm/Hz)
–100
–110
–120
–130
ATTENUATION = 47dB
ATTENUATION
= 47dB (dBm/Hz)
ATTENUATION = 21dB
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
–180 –176 –172 –168 –164 –160 –156 –152 –148 –144 –140
LO FREQUENCY (MHz)
NOISE FLOORAT 10MHz OFFSET FREQUENCY (dBm/Hz) AND (dBc/Hz)
Figure 18. 2 × LO Off Isolation vs. LO Frequency, Attenuation, Supply,
and Temperature
Figure 21. Noise Floor at 10 MHz Offset Frequency Distribution at
Worst-Case Conditions and Different Attenuation Settings
–40
1.0
0.5
UPPER THIRD
HARMONIC (fLO + 3 × fBB
)
–50
–60
0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
–3.5
–4.0
UPPER SECOND
HARMONIC (fLO + 2 × fBB
)
–70
–80
–90
–100
–110
–120
LOWER SECOND
HARMONIC (fLO – 2 × fBB
)
LOWER THIRD
HARMONIC (fLO – 3 × fBB
)
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
LO FREQUENCY (MHz)
1
10
100
1000
I AND Q BASEBAND INPUT FREQUENCY (MHz)
Figure 19. Second-Order and Third-Order Harmonic Distortion vs.
LO Frequency, Supply, and Temperature
Figure 22. Normalized I and Q Input Bandwidth
Rev. B | Page 15 of 48
ADRF6755
Data Sheet
–10
–12
–14
–16
–18
–20
–22
–24
–26
–28
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
LOWER
SIDEBAND
3 × LO
ATTENUATION = 0dB
HARMONIC
5 × LO
HARMONIC
4 × LO
HARMONIC
2 × LO
HARMONIC
ATTENUATION = 21dB AND 47dB
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
0
1
2
3
4
5
6
7
8
9
10
OUTPUT FREQUENCY (MHz)
FREQUENCY (MHz)
Figure 23. Output Return Loss at Different Attenuation Settings vs. Output
Frequency, Supply, and Temperature
Figure 26. RF Output Spectral Plot over a Wide Span
–60
–70
0
LO FREQUENCY = 2400MHz
LO FREQUENCY = 1200MHz
LO FREQUENCY = 580MHz
LO FREQUENCY = 290MHz
LO FREQUENCY = 100MHz
–10
LOWER
SIDEBAND
–80
–20
–30
–40
–50
–60
–70
–80
–90
–90
CARRIER
FEEDTHROUGH
–100
–110
–120
–130
–140
–150
–160
SUPPRESSED
SIDEBAND
THIRD
HARMONIC
SECOND
HARMONIC
100
1k
10k
100k
1M
10M
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880
OFFSET FREQUENCY (Hz)
FREQUENCY (MHz)
Figure 24. RF Output Spectral Plot over a 10 MHz Span
Figure 27. Phase Noise Performance vs. LO Frequency, Nominal Conditions
0
–60
–70
LOWER
SIDEBAND
–10
–20
–30
–40
–50
–60
–70
–80
–90
–80
LO FREQUENCY = 2500MHz
–90
CARRIER
FEEDTHROUGH
–100
–110
–120
–130
SUPPRESSED
SIDEBAND
THIRD
HARMONIC
–140
LO FREQUENCY = 100MHz
–150
–160
1825 1835 1845 1855 1865 1875 1885 1895 1905 1915 1925
100
1k
10k
100k
1M
10M
FREQUENCY (MHz)
OFFSET FREQUENCY (Hz)
Figure 28. Phase Noise Performance vs. LO Frequency, Supply,
and Temperature
Figure 25. RF Output Spectral Plot over a 100 MHz Span
Rev. B | Page 16 of 48
Data Sheet
ADRF6755
–60
–70
–60
900MHz PHASE NOISE (dBc/Hz)
1800MHz PHASE NOISE (dBc/Hz)
2100MHz PHASE NOISE (dBc/Hz)
–70
–80
–80
–90
–90
–100
–110
–120
–130
–140
–150
–160
–100
–110
–120
–130
–140
–150
–160
100
1k
10k
100k
1M
10M
100
1k
10k
100k
1M
10M
OFFSET FREQUENCY (Hz)
OFFSET FREQUENCY (Hz)
Figure 29. Phase Noise Performance Distribution at Worst-Case Conditions
Figure 32. Phase Noise Performance vs. LO Frequency, Nominal Conditions
with Narrow Loop Bandwidth
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
–50
–55
–60
–65
–70
–75
–80
+25°C 5V MAX SPUR
+85°C 4.75V MAX SPUR
+85°C 5.25V MAX SPUR
–40°C 4.75V MAX SPUR
–40°C 5.25V MAX SPUR
–85
0
–90
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
LO FREQUENCY (MHz)
LO FREQUENCY (MHz)
Figure 30. Integrated Phase Noise over an Integration Bandwidth of 1 kHz to
8 MHz vs. LO Frequency at Nominal Conditions
Figure 33. Integer Boundary Spur Performance vs. LO Frequency,
Supply, and Temperature
90
–50
1875MHz
REFERENCE SPURS AT 80MHz OFFSET
PFD SPURS AT 40MHz OFFSET
2310MHz
80
–60
70
60
50
40
30
20
10
0
–70
–80
–90
–100
–110
0.10
0.15
0.20
0.25
0.30
0.35
0.40
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
RMS JITTER (Degrees)
LO FREQUENCY (MHz)
Figure 34. Spurs > 10 MHz from Carrier vs. LO Frequency,
Supply, and Temperature
Figure 31. Integrated Phase Noise Distribution over an Integration
Bandwidth of 1 kHz to 8 MHz at 1875 MHz and 2310 MHz
Rev. B | Page 17 of 48
ADRF6755
Data Sheet
1G
100M
10M
1M
60
50
40
30
20
10
0
NOMINAL
WORST CASE
100k
10k
ACQUISITION
TO 100Hz
1k
START OF
ACQUISITION
100
10
1
LDET
NUMBER OF PFD
CYCLES TO DECLARE
LDET = 4096
0.1
–50 –30 –10 10 30 50 70 90 110 130 150 170 190 210 230 250
–1.0 –0.8 –0.6 –0.4 –0.2
0
0.2
0.4
0.6
0.8
1.0
TIME (µs)
ATTENUATOR RELATIVE STEP ACCURACY (dB)
Figure 35. PLL Frequency Settling Time at Worst-Case LO Frequency
with Lock Detect Shown
Figure 38. Attenuator Relative Step Accuracy Distribution at Nominal
and Worst-Case Conditions, LO > 300 MHz, All Attenuation Steps
5
0
14
NOMINAL
WORST CASE
12
10
8
–5
–10
–15
–20
–25
–30
–35
–40
–45
6
4
2
–50
0
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
–3.25
–2.25
–1.25
–0.25
0.25
0.75
1.75
2.75
–2.75 –1.75
–0.75
1.25
2.25
3.25
LO FREQUENCY (MHz)
ATTENUATOR RELATIVE STEP ACCURACY ACROSS
FULL OUTPUT FREQUENCY RANGE (dB)
Figure 36. Attenuator Gain vs. LO Frequency by Gain Code, All Attenuator
Code Steps
Figure 39. Attenuator Relative Step Accuracy Across Full Output
Frequency Range Distribution at Nominal and Worst-Case Conditions,
LO > 300 MHz, All Attenuation Steps
2
1.0
0.5
0
–2
–4
–6
–8
0
–0.5
–1.0
–10
–1.5
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
LO FREQUENCY (MHz)
LO FREQUENCY (MHz)
Figure 40. Attenuator Absolute Step Accuracy over all Attenuation Steps
vs. LO Frequency, Nominal Conditions
Figure 37. Attenuator Relative Step Accuracy over all Attenuation Steps
vs. LO Frequency, Nominal Conditions
Rev. B | Page 18 of 48
Data Sheet
ADRF6755
10
9
8
7
6
5
4
3
2
1
0
30
25
20
15
10
5
NOMINAL
WORST CASE
0
0
5
10
15
20
25
30
35
40
45
50
–5.0 –4.6 –4.2 –3.8 –3.4 –3.0 –2.6 –2.2 –1.8 –1.4 –1.0 –0.6 –0.2 0.2
STARTING ATTENUATOR STEP
ATTENUATOR ABSOLUTE STEP ACCURACY (dB)
Figure 44. Attenuator Settling Time to 0.5 dB for Small Steps
(1 dB to 6 dB) at Nominal Conditions
Figure 41. Attenuator Absolute Step Accuracy Distribution at Nominal
and Worst-Case Conditions, LO > 300 MHz, All Attenuation Steps
2.0
1.5
20
18
16
14
12
10
8
1.0
0.5
0
–0.5
–1.0
–1.5
6
4
2
–2.0
0
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
0
5
10
15
20
25
30
35
40
45
50
LO FREQUENCY (MHz)
STARTING ATTENUATOR STEP
Figure 42. Gain Flatness in any 40 MHz for all Attenuation Steps vs.
LO Frequency at Nominal Conditions
Figure 45. Attenuator Settling Time to 0.2 dB for Large Steps
(7 dB to 47 dB) at Nominal Conditions
10
9
8
7
6
5
4
3
2
1
0
20
18
16
14
12
10
8
6
4
2
0
0
5
10
15
20
25
30
35
40
45
50
0
5
10
15
20
25
30
35
40
45
50
STARTING ATTENUATOR STEP
STARTING ATTENUATOR STEP
Figure 46. Attenuator Settling Time to 0.5 dB for Large Steps
(7 dB to 47 dB) at Nominal Conditions
Figure 43. Attenuator Setting Time to 0.2 dB for Small Steps (1 dB to 6 dB) at
Nominal Conditions
Rev. B | Page 19 of 48
ADRF6755
Data Sheet
100
50
45
40
35
30
25
20
15
10
5
NOMINAL SETTLING TIME TO 0.2dB
NOMINAL SETTLING TIME TO 0.2dB
WORST CASE SETTLING TIME TO 0.2dB
NOMINAL SETTLING TIME TO 0.5dB
WORST CASE SETTLING TIME TO 0.5dB
WORST CASE SETTLING TIME TO 0.2dB
NOMINAL SETTLING TIME TO 0.5dB
WORST CASE SETTLING TIME TO 0.5dB
90
80
70
60
50
40
30
20
10
0
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0
3
6
9
12
15
18
21
24
27
30
33
ATTENUATOR SETTLING TIME (µs)
ATTENUATOR SETTLING TIME (µs)
Figure 47. Attenuator Settling Time to 0.2 dB and 0.5 dB Distribution at
Nominal and Worst-Case Conditions for Typical Small Step
Figure 50. Attenuator Settling Time to 0.2 dB and 0.5 dB Distribution at
Nominal and Worst-Case Conditions for Worst-Case Large Step
(47 dB to 0 dB)
100
0
NOMINAL SETTLING TIME TO 0.2dB
WORST CASE SETTLING TIME TO 0.2dB
90
NOMINAL SETTLING TIME TO 0.5dB
–10
WORST CASE SETTLING TIME TO 0.5dB
80
–20
70
60
50
40
30
20
10
0
TURN-ON = 180ns
–30
TURN-OFF= 350ns
–40
–50
–60
TXDIS
–70
0
3
6
9
12
15
18
21
24
0
1
2
3
4
5
6
7
8
ATTENUATOR SETTLING TIME (µs)
TXDIS SETTLING TIME (μs)
Figure 48. Attenuator Settling Time to 0.2 dB and 0.5 dB Distribution at
Nominal and Worst-Case Conditions for Worst-Case Small Step (36 dB to 42 dB)
Figure 51. TXDIS Settling Time at Worst-Case Supply
and Temperature
100
NOMINAL SETTLING TIME TO 0.2dB
WORST CASE SETTLING TIME TO 0.2dB
90
NOMINAL SETTLING TIME TO 0.5dB
WORST CASE SETTLING TIME TO 0.5dB
80
70
60
50
40
30
20
10
0
0
3
6
9
12
15
18
21
ATTENUATOR SETTLING TIME (µs)
Figure 49. Attenuator Settling Time to 0.2 dB and 0.5 dB Distribution at
Nominal and Worst-Case Conditions for Typical Large Step
Rev. B | Page 20 of 48
Data Sheet
ADRF6755
THEORY OF OPERATION
FROM
REFIN
PIN
OVERVIEW
TO
PFD
×2
5-BIT
÷2
DOUBLER
R-DIVIDER
The ADRF6755 device can be divided into the following basic
building blocks:
Figure 53. Reference Input Path
The PFD frequency equation is
PFD = fREFIN × [(1 + D)/(R × (1 + T))]
where:
REFIN is the reference input frequency.
D is the doubler bit.
•
•
•
•
•
PLL synthesizer and VCO
Quadrature modulator
Attenuator
f
(1)
Voltage regulator
f
I2C/SPI interface
R is the programmed divide ratio of the binary 5-bit
programmable reference divider (1 to 32).
T is the R/2 divider setting bit (CR10[6] = 0 or 1).
Each of these building blocks is described in detail in the
sections that follow.
PLL SYNTHESIZER AND VCO
Overview
If no division is required, it is recommended that the 5-bit
R-divider and the divide-by-2 be disabled by setting CR5[4] = 0.
If an even numbered division is required, enable the divide-by-2
by setting CR5[4] = 1 and CR10[6] = 1 and implement the
remainder of the division in the 5-bit R-divider. If an odd number
division is required, set CR5[4] = 1 and implement all of the
division in the 5-bit R-divider.
The phase-locked loop (PLL) consists of a fractional-N frequency
synthesizer with a 25-bit fixed modulus, allowing a frequency
resolution of less than 1 Hz over the entire frequency range. It
also has an integrated voltage-controlled oscillator (VCO) with
a fundamental output frequency ranging from 2310 MHz to
4800 MHz. An RF divider, controlled by Register CR28,
Bits[2:0], extends the lower limit of the local oscillator (LO)
frequency range to 100 MHz. See Table 6 for more details on
Register CR28.
RF Fractional-N Divider
The RF fractional-N divider allows a division ratio in the PLL
feedback path that can range from 23 to 4095. The relationship
between the fractional-N divider and the LO frequency is
described in the INT and FRAC Relationship section.
Reference Input Section
The reference input stage is shown Figure 52. SW1 and SW2 are
normally closed switches. SW3 is normally open. When power-
down is initiated, SW3 is closed, and SW1 and SW2 are open. This
ensures that there is no loading of the REFIN pin at power-down.
INT and FRAC Relationship
The integer (INT) and fractional (FRAC) values make it possible to
generate output frequencies that are spaced by fractions of the
phase frequency detector (PFD) frequency. See the Example—
Changing the LO Frequency section for more information.
POWER-DOWN
CONTROL
The LO frequency equation is
100kΩ
SW2
NC
LO = fPFD × (INT + (FRAC/225))/2RFDIV
where:
LO is the local oscillator frequency.
PFD is the PFD frequency.
(2)
TO
R-DIVIDER
REFIN
NC
SW1
BUFFER
SW3
NC
f
Figure 52. Reference Input Stage
INT is the integer component of the required division factor
and is controlled by the CR6 and CR7 registers.
Reference Input Path
FRAC is the fractional component of the required division
factor and is controlled by the CR0 to CR3 registers.
RFDIV is set in Register CR28, Bits[2:0], and controls the
setting of the divider at the output of the PLL.
The on-chip reference frequency doubler allows the input
reference signal to be doubled. This is useful for increasing the
PFD comparison frequency. Making the PFD frequency higher
improves the noise performance of the system. Doubling the
PFD frequency usually improves the in-band phase noise
performance by up to 3 dBc/Hz.
25
RF N-DIVIDER
N-COUNTER
N = INT + FRAC/2
TO
PFD
FROM VCO
OUTPUT
DIVIDERS
The 5-bit R-divider allows the input reference frequency (REFIN) to
be divided down to produce the reference clock to the PFD.
Division ratios from 1 to 32 are allowed.
THIRD-ORDER
FRACTIONAL
INTERPOLATOR
INT
REG
FRAC
VALUE
An additional divide-by-2 (÷2) function in the reference input
path allows for a greater division range.
Figure 54. RF Fractional-N Divider
Rev. B | Page 21 of 48
ADRF6755
Data Sheet
2.5
2.3
2.1
1.9
1.7
1.5
1.3
1.1
0.9
0.7
0.5
Phase Frequency Detector (PFD) and Charge Pump
The PFD takes inputs from the R-divider and the N-counter and
produces an output proportional to the phase and frequency differ-
ence between them (see Figure 55 for a simplified schematic).
The PFD includes a fixed delay element that sets the width of
the antibacklash pulse, ensuring that there is no dead zone in
the PFD transfer function.
UP
HI
D1
Q1
U1
+IN
CLR1
CHARGE
PUMP
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
CP
DELAY
DOWN
U3
LO FREQUENCY (MHz)
Figure 56. VTUNE vs. LO Frequency
The VCO displays a variation of KVCO as VTUNE varies within the
band and from band to band. Figure 57 shows how KVCO varies
across the full frequency range. Figure 57 is useful when
calculating the loop filter bandwidth and individual loop filter
components using ADISimPLL™. ADISimPLL is an Analog
Devices, Inc., simulator that aids in PLL design, particularly
with respect to the loop filter. It reports parameters such as phase
noise, integrated phase noise, and acquisition time for a
particular set of input conditions. ADISimPLL can be
downloaded from www.analog.com/adisimpll.
CLR2
D2 Q2
HI
U2
–IN
Figure 55. PFD Simplified Schematic
Lock Detect (LDET)
LDET (Pin 44) signals when the PLL has achieved lock to an
error frequency of less than 100 Hz. On a write to Register CR0,
a new PLL acquisition cycle starts, and the LDET signal goes
low. When lock has been achieved, this signal returns high.
40
Voltage-Controlled Oscillator (VCO)
The VCO core in the ADRF6755 consists of three separate VCOs,
each with 16 overlapping bands. This configuration of 48 bands
allows the VCO frequency range to extend from 2310 MHz to
4800 MHz. The three VCOs are divided by a programmable
divider, RFDIV, controlled by Register CR28, Bits[2:0]. This
divider provides divisions of 1, 2, 4, 8, and 16 to ensure that the
frequency range is extended from 144.375 MHz (2310 MHz/16)
to 4800 MHz (4800 MHz/1). A divide-by-2 quadrature circuit in
the path to the modulator then provides the full LO frequency
range from 100 MHz to 2400 MHz.
30
20
10
0
Figure 56 shows a sweep of VTUNE vs. LO frequency demonstrating
the three VCOs overlapping and the multiple overlapping bands
within each VCO at the LO frequency range of 100 MHz to
2400 MHz. Note that Figure 56 includes the RFDIV being
incorporated to provide further divisions of the fundamental VCO
frequency; thus, each VCO is used on multiple different occasions
throughout the full LO frequency range. The choice of three
16-band VCOs and an RFDIV allows the wide frequency range to
be covered without large VCO sensitivity (KVCO) or resultant
poor phase noise and spurious performance.
100 300 500 700 900 1100 1300 1500 1700 1900 2100 2300 2500
LO FREQUENCY (MHz)
Figure 57. KVCO vs. LO Frequency
Autocalibration
The correct VCO and band are chosen automatically by the
VCO and band select circuitry when Register CR0 is updated.
This is referred to as autocalibration. The autocalibration time
is set by Register CR25.
Autocalibration Time = (BSCDIV × 28)/PFD
(3)
where:
BSCDIV = Register CR25, Bits[7:0].
PFD = PFD frequency.
For a PFD frequency of 40 MHz, set BSCDIV = 100 to set an
autocalibration time of 70 µs.
Rev. B | Page 22 of 48
Data Sheet
ADRF6755
Note that BSCDIV must be recalculated if the PFD frequency is
changed. The recommended autocalibration setting is 70 µs.
During this time, the VCO VTUNE is disconnected from the output
of the loop filter and is connected to an internal reference voltage.
A typical frequency acquisition is shown in Figure 58.
1G
Programming the Correct LO Frequency
There are two steps to programming the correct LO frequency.
The user must calculate the RFDIV value based on the required
LO frequency and PFD frequency, and the N-divider ratio that
is required in the PLL.
1. Calculate the value of RFDIV, which is used to program
Register CR28, Bits[2:0] and CR27, Bit 4 from the
following lookup table, Table 6.
100M
10M
1M
Table 6. RFDIV Lookup Table
AUTOCAL
100k
10k
1k
TIME (μs)
CR28[2:0]
= RFDIV
LO Frequency (MHz)
1155 < LO < 2400
RFDIVIDER
Divide-by-1
Divide-by-2
Divide-by-4
Divide-by-8
Divide-by-16
CR27[4]
ACQUISITION TO 100Hz
000
1
0
0
0
0
100
10
577.5 < LO ≤ 1155
288.75 < LO ≤ 577.5
144.375 < LO ≤ 288.75
100 < LO ≤ 144.375
001
010
011
1
100
0.1
0
25
50
75
100 125 150 175 200 225 250
TIME (µs)
2. Using the following equation, calculate the value of the
N-divider:
Figure 58. PLL Acquisition
N = (2RFDIV × LO)/fPFD
(4)
After autocalibration, normal PLL action resumes, and the
correct frequency is acquired to within a frequency error of
100 Hz in 170 μs typically. For a maximum cumulative step of
100 kHz/2RFDIV, autocalibration can be turned off by setting
Register CR24, Bit 0 = 1. This enables cumulative PLL acquisi-
tions of ≤100 kHz (for RFDIV = ÷1, 50 kHz for RFDIV = ÷2,
and so on) to occur without the autocalibration procedure,
which improves acquisition times significantly (see Figure 59).
1M
where:
N is the N-divider value.
RFDIV is the setting in Register CR28, Bits[2:0].
LO is the local oscillator frequency.
f
PFD is the PFD frequency.
This equation is a different representation of Equation 2.
Example to Program the Correct LO Frequency
Assume that the PFD frequency is 40 MHz and that the
required LO frequency is 1875 MHz.
From Table 6, 2RFDIV = 1 (RFDIV = 0)
100k
10k
1k
N = (1 × 1875 × 106)/(40 × 106) = 46.875
The N-divider value is composed of integer (INT) and
fractional (FRAC) components according to the following
equation:
ACQUISITION TO 100Hz
100
N = INT + FRAC/225
(5)
10
1
INT = 46 and FRAC = 29,360,128
The appropriate registers must then be programmed according to
the register map. The order in which the registers are programmed
is important. Writing to CR0 initiates a PLL acquisition cycle.
If the programmed LO frequency requires a change in the value
of CR27[4] (see Table 6), CR27 should be the last register
programmed, preceded by CR0. If the programmed LO frequency
does not require a change in the value of CR27[4], it is optional
to omit the write to CR27 and, in that case, CR0 should be the
last register programmed.
0
50
100
150
200
TIME (μs)
Figure 59. PLL Acquisition Without Autocalibration for a 100 kHz Step
Rev. B | Page 23 of 48
ADRF6755
Data Sheet
differential termination is recommended at the baseband inputs,
and this dominates the input impedance as seen by the input
baseband signal. This ensures that the input impedance, as seen by
the input circuit, remains flat across the baseband bandwidth.
See Figure 62 for a typical configuration.
QUADRATURE MODULATOR
Overview
A basic block diagram of the ADRF6755 quadrature modulator
circuit is shown in Figure 60. The VCO/RFDIVIDER generates
a signal at the 2× LO frequency, which is then divided down to give
a signal at the LO frequency. This signal is then split into in-phase
and quadrature components to provide the LO signals that drive
the mixers.
CURRENT OUTPUT DAC
(EXAMPLE: AD9779)
ADRF6755
OUT1_P
IBB
50Ω
50Ω
LOW-
PASS
V-TO-I
100Ω
100Ω
FILTER
IBB
IBB
OUT1_N
OUT2_N
IBB
QBB
50Ω
50Ω
LOW-
PASS
FILTER
QUAD
RFOUT TO
ATTENUATOR
÷2
RF DIVIDER
V-TO-I
VCO
PHASE
SPLITTER
QBB
OUT2_P
Figure 62. Typical Baseband Input Configuration
QBB
QBB
The swing of the AD9779 output currents ranges from 0 mA to
20 mA. The ac voltage swing is 1 V p-p single-ended or 2 V p-p
differential with the 50 Ω resistors in place. The 100 Ω differen-
tial termination resistors at the baseband inputs have the effect
of limiting this swing without changing the dc bias condition of
500 mV. The low-pass filter is used to filter the DAC outputs
and remove images when driving a modulator.
Figure 60. Block Diagram of the Quadrature Modulator
The I and Q baseband input signals are converted to currents by
the V-to-I stages, which then drive the two mixers. The outputs
of these mixers combine to feed the single-ended output. This
single-ended output is then fed to the attenuator and, finally, to
the external RFOUT signal pin.
Baseband Inputs
Another consideration is that the baseband inputs actually source a
current of 240 μA out of each of the four inputs. This current must
be taken into account when setting up the dc bias of 500 m V. In
the initial example based on Figure 61, an error of 12 mV occurs
due to the 240 μA current flowing through the 50 Ω resistor.
Analog Devices recommends that the accuracy of the dc bias
should be 500 mV 25 mV. It is also important that this 240 μA
current have a dc path to ground.
The baseband inputs, QBB,
, IBB, and
, must be driven
IBB
QBB
from a differential source. The nominal drive level of 0.9 V p-p
differential (450 mV p-p on each pin) should be biased to a
common-mode level of 500 mV dc.
To set the dc bias level at the baseband inputs, refer to Figure 61.
The average output current on each of the AD9779 outputs is
10 mA. A current of 10 mA flowing through each of the 50 Ω
resistors to ground produces the desired dc bias of 500 mV at
each of the baseband inputs.
Optimization
The carrier feedthrough and the sideband suppression
performance of the ADRF6755 can be improved over the
specifications in Table 1 by using the following optimization
techniques.
CURRENT OUTPUT DAC
(EXAMPLE: AD9779)
ADRF6755
OUT1_P
IBB
50Ω
50Ω
Carrier Feedthrough Nulling
Carrier feedthrough results from dc offsets that occur between
the P and N inputs of each of the differential baseband inputs.
Normally these inputs are set to a dc bias of approximately 500 m V.
OUT1_N
OUT2_N
IBB
QBB
50Ω
50Ω
However, if a dc offset is introduced between the P and N inputs of
either or both I and Q inputs, the carrier feedthrough is affected
in either a positive or a negative fashion. Note that the dc bias
level remains at 500 mV (average P and N level). The I channel
offset is often held constant while the Q channel offset is varied
until a minimum carrier feedthrough level is obtained. Then,
while retaining the new Q channel offset, the I channel offset is
adjusted until a new minimum is reached. This is usually per-
formed at a single frequency and, thus, is not optimized over
the complete frequency range. Multiple optimizations at different
QBB
OUT2_P
Figure 61. Establishing DC Bias Level on Baseband Inputs
The differential baseband inputs (QBB,
,
, and IBB)
QBB IBB
consist of the bases of PNP transistors, which present a high
impedance of about 30 kΩ in parallel with approximately 2 pF
of capacitance. The impedance is approximately 30 kΩ below
1 MHz and starts to roll off at higher frequency. A 100 Ω
Rev. B | Page 24 of 48
Data Sheet
ADRF6755
frequencies must be performed to ensure optimum carrier feed-
through across the full frequency range.
the CS pin (Pin 27). Bits[4:0] of the slave address are set to all
0s. The slave address consists of the seven MSBs of an 8-bit
word. The LSB of the word sets either a read or a write operation
(see Figure 63). Logic 1 corresponds to a read operation, whereas
Logic 0 corresponds to a write operation.
Sideband Suppression Nulling
Sideband suppression results from relative gain and relative phase
offsets between the I channel and Q channel and can be optimized
through adjustments to those two parameters. Adjusting only
one parameter improves the sideband suppression only to a
point. For optimum sideband suppression, an iterative adjustment
between phase and amplitude is required.
To control the device on the bus, the following protocol must
be followed. The master initiates a data transfer by establishing
a start condition, defined by a high-to-low transition on SDA
while SCL remains high. This indicates that an address/data
stream follows. All peripherals respond to the start condition
and shift the next eight bits (the 7-bit address and the R/W bit).
The bits are transferred from MSB to LSB. The peripheral that
recognizes the transmitted address responds by pulling the data
line low during the ninth clock pulse. This is known as an
acknowledge bit. All other devices then withdraw from the bus
and maintain an idle condition. During the idle condition, the
device monitors the SDA and SCL lines waiting for the start
condition and the correct transmitted address. The R/W bit
determines the direction of the data. Logic 0 on the LSB of the
first byte indicates that the master writes information to the
peripheral. Logic 1 on the LSB of the first byte indicates that the
master reads information from the peripheral.
ATTENUATOR
The digital attenuator consists of six attenuation blocks: 1 dB,
2 dB, 4 dB, 8 dB, and two 16 dB blocks; each is separately
controlled. Each attenuation block consists of field effect transistor
(FET) switches and resistors that form either a pi-shaped or a
T-shaped attenuator. By controlling the states of the FET switches
through the control lines, each attenuation block can be set to
the pass state (0 dB) or the attenuation state (1 dB to 47 dB).
The various combinations of the six blocks provide the
attenuation states from 0 dB to 47 dB in 1 dB increments.
VOLTAGE REGULATOR
The voltage regulator is powered from a 5 V supply that is
provided by VCC1 (Pin 11) and produces a 3.3 V nominal
regulated output voltage, REGOUT, on Pin 12. This pin must
be connected (external to the IC) to the VREG1 through VREG6
package pins.
The ADRF6755 acts as a standard slave device on the bus. The data
on the SDA pin (Pin 29) is eight bits long, supporting the 7-bit
addresses plus the R/W bit. The ADRF6755 has 34 subaddresses
to enable the user-accessible internal registers. Therefore, it
interprets the first byte as the device address and the second
byte as the starting subaddress. Auto-increment mode is supported,
which allows data to be read from or written to the starting sub-
address and each subsequent address without manually addressing
the subsequent subaddress. A data transfer is always terminated
by a stop condition. The user can also access any unique subaddress
register on a one-by-one basis without updating all registers.
Decouple the regulator output (REGOUT) with a parallel
combination of 10 pF and 220 µF capacitors. The 220 µF
capacitor, which is recommended for best performance,
decouples broadband noise, leading to better phase noise. Each
VREGx pin should have the following decoupling capacitors:
100 nF multilayer ceramic with an additional 10 pF in parallel,
both placed as close as possible to the device under test (DUT)
power supply pins. X7R or X5R capacitors are recommended.
See the Evaluation Board section for more information.
Stop and start conditions can be detected at any stage of the data
transfer. If these conditions are asserted out of sequence with
normal read and write operations, they cause an immediate jump
to the idle condition. If an invalid subaddress is issued by the
user, the ADRF6755 does not issue an acknowledge and returns to
the idle condition. In a no acknowledge condition, the SDA line is
not pulled low on the ninth pulse. See Figure 64 and Figure 65
for sample write and read data transfers, Figure 66 for the timing
protocol, and Figure 2 for a more detailed timing diagram.
I2C INTERFACE
The ADRF6755 supports a 2-wire, I2C-compatible serial bus
that drives multiple peripherals. The serial data (SDA) and serial
clock (SCL) inputs carry information between any devices that
are connected to the bus. Each slave device is recognized by a
unique address. The ADRF6755 has two possible 7-bit slave
addresses for both read and write operations. The MSB of the
7-bit slave address is set to 1. Bit A5 of the slave address is set by
R/W
CTRL
SLAVE ADDRESS[6:0]
1
A5
0
0
0
0
0
X
MSB = 1 SET BY
PIN 27
0 = WR
1 = RD
(CS)
Figure 63. Slave Address Configuration
Rev. B | Page 25 of 48
ADRF6755
Data Sheet
S
SLAVE ADDR, LSB = 0 (WR) A(S) SUBADDR A(S) DATA A(S)
DATA A(S)
P
S = START BIT
P = STOP BIT
A(S) = ACKNOWLEDGE BY SLAVE
Figure 64. I2C Write Data Transfer
S
SLAVE ADDR, LSB = 0 (WR) A(S) SUBADDR A(S)
S
SLAVE ADDR, LSB = 1 (RD) A(S) DATA A(M)
DATA A(M) P
S = START BIT
P = STOP BIT
A(M) = NO ACKNOWLEDGE BY MASTER
A(S) = ACKNOWLEDGE BY SLAVE
A(M) = ACKNOWLEDGE BY MASTER
Figure 65. I2C Read Data Transfer
START BIT
SDA
STOP BIT
SLAVE ADDRESS
SUBADDRESS
DATA
A6
A5
A7
A0
D7
D0
SCL
S
P
WR
ACK
ACK
ACK
SLAVE
ADDR[4:0]
SUBADDR[6:1]
DATA[6:1]
Figure 66. I2C Data Transfer Timing
Rev. B | Page 26 of 48
Data Sheet
ADRF6755
SPI Serial Interface Functionality
SPI INTERFACE
The SPI serial interface of the ADRF6755 consists of the CS,
SDI (SDI/SDA), CLK (CLK/SCL), and SDO pins. CS is used to
select the device when more than one device is connected to the
serial clock and data lines. CLK is used to clock data in and out
of the part. The SDI pin is used to write to the registers. The
SDO pin is a dedicated output for the read mode. The part operates
in slave mode and requires an externally applied serial clock to
the CLK pin. The serial interface is designed to allow the part to be
interfaced to systems that provide a serial clock that is synchronized
to the serial data.
The ADRF6755 also supports the SPI protocol. The part powers
up in I2C mode but is not locked in this mode. To stay in I2C
mode, it is recommended that the user tie the CS line to either
3.3 V or GND, thus disabling SPI mode. It is not possible to lock
the I2C mode, but it is possible to select and lock the SPI mode.
To select and lock the SPI mode, three pulses must be sent to the
CS pin, as shown in Figure 67. When the SPI protocol is locked
in, it cannot be unlocked while the device is still powered up. To
reset the serial interface, the part must be powered down and
powered up again.
Figure 68 shows an example of a write operation to the
Serial Interface Selection
ADRF6755. Data is clocked into the registers on the rising edge
of CLK using a 24-bit write command. The first eight bits
represent the write command, 0xD4; the next eight bits are the
register address; and the final eight bits are the data to be written
to the specific register. Figure 69 shows an example of a read
operation. In this example, a shortened 16-bit write command is
first used to select the appropriate register for a read operation,
the first eight bits representing the write command, 0xD4, and
the final eight bits representing the specific register. Then the
CS line is pulsed low for a second time to retrieve data from the
selected register using a 16-bit read command, the first eight
bits representing the read command, 0xD5, and the final eight
bits representing the contents of the register being read. Figure 3
shows the timing for both SPI read and SPI write operations.
The CS pin controls selection of the I2C or SPI interface.
Figure 67 shows the selection process that is required to lock
the SPI mode. To communicate with the part using the SPI
protocol, three pulses must be sent to the CS pin. On the third
rising edge, the part selects and locks the SPI protocol. Consistent
with most SPI standards, the CS pin must be held low during all
SPI communication to the part and held high at all other times.
A
B
C
CS
(STARTING
HIGH)
SPI LOCKED ON
THIRD RISING EDGE
SPI FRAMING
EDGE
CS
(STARTING
LOW)
A
B
C
SPI LOCKED ON
THIRD RISING EDGE
SPI FRAMING
EDGE
Figure 67. Selecting the SPI Protocol
Rev. B | Page 27 of 48
ADRF6755
Data Sheet
• • •
CS
• • •
CLK
SDI
• • •
D0
D7
START
D6
D5
D4
D3
D2
D1
D0
D7
D6
D5
D4
D3
D2
D1
WRITE
REGISTER
ADDRESS
COMMAND [0xD4]
CS
(CONTINUED)
CLK
(CONTINUED)
SDI
(CONTINUED)
D7
D6
D5
D4
D3
D2
D1
D0
STOP
DATA
BYTE
Figure 68. SPI Byte Write Example
• • •
CS
• • •
CLK
• • •
SDI
D7
D6
D5
D4
D3
D2
D1
D0
D0
D7
D6
D5
D4
D3
D2
D1
START
WRITE
COMMAND [0xD4]
REGISTER
ADDRESS
CS
CLK
SDI
D7
D6
X
D5
X
D4
X
D3
X
D2
D1
D0
X
X
X
X
X
X
X
X
X
X
X
X
D7
D6
D5
D4
D3
D2
D1
D0
SDO
STOP
START
READ
COMMAND [0xD5]
DATA
BYTE
Figure 69. SPI Byte Read Example
Rev. B | Page 28 of 48
Data Sheet
ADRF6755
Reference Input Path
PROGRAM MODES
The reference input path consists of a reference frequency doubler,
a 5-bit reference divider, and a divide-by-2 function (see Figure 53).
The doubler is programmed through Register CR10, Bit 5. The
5-bit divider and divide-by-2 are enabled by programming
Register CR5, Bit 4, and the division ratio is programmed through
Register CR10, Bits[4:0]. The R/2 divider is programmed through
Register CR10, Bit 6. Note that these registers are double-buffered.
The ADRF6755 has 34 8-bit registers to allow program control
of a number of functions. Either an SPI or an I2C interface can
be used to program the register set. For details about the interfaces
and timing, see Figure 63 to Figure 69. The registers are
documented in Table 8 to Table 28.
Several settings in the ADRF6755 are double-buffered. These
settings include the FRAC value, the INT value, the 5-bit R-divider
value, the reference frequency doubler, the R/2 divider, the RFDIV
value, and the charge pump current setting. This means that
two events must occur before the part uses a new value for any
of the double-buffered settings. First, the new value is latched
into the device by writing to the appropriate register. Next, a
new write must be performed on Register CR0. When
Charge Pump Current
Register CR9, Bits[7:4], specify the charge pump current setting.
With an RSET value of 4.7 kΩ, the maximum charge pump current is
5 mA. The following equation applies:
I
CPmax = 23.5/RSET
The charge pump current has 16 settings from 312.5 μA to 5 mA.
For the loop filter that is specified in the application solution, a
charge pump current of 5 mA (Register CR9[7:4] = 0xF) gives a
loop bandwidth of 100 kHz, which is the recommended loop
bandwidth setting.
Register CR0 is written, a new PLL acquisition takes place.
For example, updating the fractional value involves a write to
Register CR3, Register CR2, Register CR1, and Register CR0.
Register CR3 should be written to first, followed by Register CR2
and Register CR1, and, finally, Register CR0. The new acquisition
begins after the write to Register CR0. Double buffering ensures
that the bits written to do not take effect until after the write to
Register CR0.
Transmit Disable Control (TXDIS)
The transmit disable control (TXDIS) is used to disable the RF out-
put. TXDIS is normally held low. When asserted (brought high), it
disables the RF output. Register CR14 is used to control which
circuit blocks are powered down when TXDIS is asserted. To meet
both the off isolation power specifications and the turn-on/
turn-off settling time specifications, a value of 0x80 should be
loaded into Register CR14. This effectively ensures that the
attenuator is always enabled when TXDIS is asserted, even if other
circuitry is disabled.
12-Bit Integer Value
Register CR7 and Register CR6 program the integer value (INT)
of the feedback division factor (N); see Equation 5 for details.
The INT value is a 12-bit number whose MSBs are programmed
through Register CR7, Bits[3:0]. The LSBs are programmed
through Register CR6, Bits[7:0]. The LO frequency setting is
described by Equation 2. An alternative to this equation is
provided by Equation 4, which details how to set the N-divider
value. Note that these registers are double buffered.
Power-Down/Power-Up Control Bits
The four programmable power-up and power-down control bits
are as follows:
25-Bit Fractional Value
Register CR12, Bit 2. Master power control bit for the PLL,
including the VCO. This bit is normally set to a default value
of 0 to power up the PLL.
Register CR28, Bit 4. Controls the RFDIVIDER. This bit is
normally set to a default value of 0 to power up the
RFDIVIDER.
Register CR3 to Register CR0 program the fractional value (FRAC)
of the feedback division factor (N); see Equation 5 for details.
The FRAC value is a 25-bit number whose MSB is programmed
through Register CR3, Bit 0. The LSB is programmed through
Register CR0, Bit 0. The LO frequency setting is described by
Equation 2. An alternative to this equation is described by
Equation 4, which details how to set the N-divider value. Note
that these registers are double buffered.
Register CR27, Bit 2. Controls the LO monitor outputs,
LOMON and
. The default is 0 when the monitor
LOMON
outputs are powered down. Setting this bit to 1 powers
up the monitor outputs to one of four options, −6 dBm,
−12 dBm, −18 dBm, or −24 dBm, as controlled by
Register CR27, Bits[1:0].
Register CR29, Bit 0. Controls the quadrature modulator
power. The default is 0, which powers down the modulator.
Write a 1 to this bit to power up the modulator.
RFDIV Value
The RFDIV value is dependent on the value of the LO frequency.
The RFDIV value can be selected from the list in Table 6. Apply
the selected RFDIV value to Equation 4, together with the LO
frequency and PFD frequency values, to calculate the correct
N-divider value.
Rev. B | Page 29 of 48
ADRF6755
Data Sheet
Lock Detect (LDET)
The appropriate setting to use depends on the PFD frequency as
well as the desired accuracy when LDET is declared. The LDET
setting does not affect the acquisition time of the PLL. It only
affects the time at which LDET goes high.
Lock detect is enabled by setting Register CR23, Bit 4, to 1. The
lock detect circuit is based on monitoring the up/down pulses
from the PFD. As acquisition proceeds, the width of these
pulses reduces until they are less than a target width (set by
CR23[2]). At this point, a count of the number of successive
PFD cycles is initiated, where the width of the up/down pulses
remains less that the target width. When this count reaches a
target count (set by CR13[6] and CR23[3]), LDET is set. The
truth table for declaring LDET is given in Table 7.
VCO Autocalibration
The VCO uses an autocalibration technique to select the correct
VCO and band, as explained in the Autocalibration section.
Register CR24, Bit 0, controls whether the autocalibration is
enabled. For normal operation, autocalibration must be enabled.
However, if using cumulative frequency steps of 100 kHz/2RFDIV
or less, autocalibration can be disabled by setting this bit to 1
and then a new acquisition is initiated by writing to Register CR0.
Table 7. Declaring LDET
LDCount1
CR13[6]
LDCount0
CR23[3]
Number of PFD Cycles to
Declare LDET
Attenuator
0
0
1
1
0
1
0
1
2048
3072
4096
16,384
The attenuator can be programmed from 0 dB to 47 dB in steps
of 1 dB. Control is through Register CR30, Bits[5:0].
Revision Readback
The revision of the silicon die can be read back via Register CR33.
Rev. B | Page 30 of 48
Data Sheet
ADRF6755
REGISTER MAP
REGISTER MAP SUMMARY
Table 8. Register Map Summary
Register Address (Hex)
Register Name
CR0
CR1
CR2
CR3
CR4
CR5
CR6
CR7
Type
Description
0x00
0x01
0x02
0x03
0x04
0x05
0x06
0x07
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read/write
Read only
Read only
Read only
Fractional Word 4
Fractional Word 3
Fractional Word 2
Fractional Word 1
Reserved
5-bit reference dividers enable
Integer Word 2
Integer Word 1 and MUXOUT control
Reserved
Charge pump current setting
Reference frequency control
Reserved
PLL power-up
Lock Detector Control 2
TXDIS control
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Lock Detector Control 1
Autocalibration
Autocalibration Timer
Reserved
LO monitor output and LO selection
LO selection
Modulator
Attenuator
Reserved
Reserved
0x08
0x09
CR8
CR9
0x0A
0x0B
0x0C
0x0D
0x0E
0x0F
0x10
0x11
0x12
0x13
0x14
0x15
0x16
0x17
0x18
0x19
0x1A
0x1B
CR10
CR11
CR12
CR13
CR14
CR15
CR16
CR17
CR18
CR19
CR20
CR21
CR22
CR23
CR24
CR25
CR26
CR27
CR28
CR29
CR30
CR31
CR32
CR33
0x1C
0x1D
0x1E
0x1F
0x20
0x21
Revision code
Rev. B | Page 31 of 48
ADRF6755
Data Sheet
REGISTER BIT DESCRIPTIONS
Table 9. Register CR0 (Address 0x00), Fractional Word 4
Bit
Table 13. Register CR5 (Address 0x05), 5-Bit Reference
Divider Enable
Description1
Bit
Description
7
6
5
4
3
2
1
0
Fractional Word F7
Fractional Word F6
Fractional Word F5
Fractional Word F4
Fractional Word F3
Fractional Word F2
Fractional Word F1
Fractional Word F0 (LSB)
7
6
5
4
Set to 0
Set to 0
Set to 0
5-bit R-divider and divide-by-2 enable1
0 = disable 5-bit R-divider and divide-by-2 (default)
1 = enable 5-bit R-divider and divide-by-2
Set to 0
Set to 0
Set to 0
Set to 0
3
2
1
0
1 Double-buffered. Loaded on a write to Register CR0.
Table 10. Register CR1 (Address 0x01), Fractional Word 3
Bit
Description1
1 Double-buffered. Loaded on a write to Register CR0.
7
6
5
4
3
2
1
0
Fractional Word F15
Fractional Word F14
Fractional Word F13
Fractional Word F12
Fractional Word F11
Fractional Word F10
Fractional Word F9
Fractional Word F8
Table 14. Register CR6 (Address 0x06), Integer Word 2
Bit
Description1
7
6
5
4
3
2
1
0
Integer Word N7
Integer Word N6
Integer Word N5
Integer Word N4
Integer Word N3
Integer Word N2
Integer Word N1
Integer Word N0
1 Double-buffered. Loaded on a write to Register CR0.
Table 11. Register CR2 (Address 0x02), Fractional Word 2
Bit
Description1
1 Double-buffered. Loaded on a write to Register CR0.
7
6
5
4
3
2
1
0
Fractional Word F23
Fractional Word F22
Fractional Word F21
Fractional Word F20
Fractional Word F19
Fractional Word F18
Fractional Word F17
Fractional Word F16
Table 15. Register CR7 (Address 0x07), Integer Word 1 and
MUXOUT Control
Bit
Description
[7:4]
MUXOUT control
0000 = tristate
0001 = logic high
0010 = logic low
1101 = reference clock/2
1110 = RF fractional-N divider clock/2
Integer Word N111
Integer Word N101
Integer Word N91
1 Double-buffered. Loaded on a write to Register CR0.
3
2
1
0
Table 12. Register CR3 (Address 0x03), Fractional Word 1
Bit
Description
7
Set to 0
Integer Word N81
6
Set to 0
5
4
Set to 0
Set to 0
1 Double-buffered. Loaded on a write to Register CR0.
3
Set to 0
2
Set to 1
1
0
Set to 0
Fractional Word F24 (MSB)1
1 Double-buffered. Loaded on a write to Register CR0.
Rev. B | Page 32 of 48
Data Sheet
ADRF6755
Table 16. Register CR9 (Address 0x09), Charge Pump
Current Setting
Table 18. Register CR12 (Address 0x0C), PLL Power-Up
Bit
Description
Bit
Description
7
6
5
4
3
2
Set to 0
Set to 0
Set to 0
Set to 1
[7:4]
Charge pump current1
0000 = 0.3125 mA (default)
0001 = 0.63 mA
0010 = 0.94 mA
0011 = 1.25 mA
0100 = 1.57 mA
0101 = 1.88 mA
0110 = 2.19 mA
0111 = 2.50 mA
1000 = 2.81 mA
1001 = 3.13 mA
1010 = 3.44 mA
1011 = 3.75 mA
1100 = 4.06 mA
1101 = 4.38 mA
1110 = 4.69 mA
1111 = 5.00 mA
Set to 0
Set to 1
Power down PLL
0 = power up PLL (default)
1 = power down PLL
Set to 0
1
0
Set to 0
Table 19. Register CR13 (Address 0x0D), Lock Detector Control 2
Bit
Description
7
6
5
4
3
2
1
0
Set to 1
LDCount1 (see Table 7)
Set to 1
Set to 0
Set to 1
Set to 0
Set to 0
Set to 0
3
2
1
0
Set to 0
Set to 0
Set to 0
Table 20. Register CR14 (Address 0x0E), TXDIS Control
1 Double-buffered. Loaded on a write to Register CR0.
Bit
Description
7
TXDIS_LOCLK
0 = LO clock always running
1 = stop LO clock when TXDIS = 1
Table 17. Register CR10 (Address 0x0A), Reference
Frequency Control
Bit
Description
Set to 01
6
5
4
3
2
1
0
Set to 0
Set to 0
Set to 0
Set to 0
Set to 0
Set to 0
Set to 0
7
6
R/2 divider setting1
0 = bypass R/2 divider (default)
1 = select R/2 divider
Reference frequency doubler (R-doubler) enable1
0 = disable doubler (default)
1 = enable doubler
5
[4:0]
5-bit R-divider setting1
00000 = divide by 32 (default)
00001 = divide by 1
00010 = divide by 2
…
Table 21. Register CR23 (Address 0x17), Lock Detector Control 1
Bit
Description
7
Set to 0
6
Set to 1
5
Set to 1
11110 = divide by 30
11111 = divide by 31
4
Lock detector enable
0 = lock detector disabled (default)
1 = lock detector enabled
Lock detector up/down count, LDCount0 (see Table 7)
Lock detector precision
0 = low, coarse (10 ns)
1 = high, fine (6 ns)
Set to 0
1 Double-buffered. Loaded on a write to Register CR0.
3
2
1
0
Set to 0
Rev. B | Page 33 of 48
ADRF6755
Data Sheet
Table 22. Register CR24 (Address 0x18), Autocalibration
Table 26. Register CR29 (Address 0x1D), Modulator
Bit
Description
Bit
Description
7
Set to 0
7
Set to 1
6
Set to 0
6
Set to 0
5
Set to 0
5
Set to 0
4
Set to 1
4
Set to 0
3
Set to 1
3
Set to 0
2
Set to 0
2
Set to 0
1
Set to 0
1
Set to 0
0
Disable autocalibration
0 = enable autocalibration (default)
1 = disable autocalibration
0
Power up modulator
0 = power down (default)
1 = power up
Table 23. Register CR25 (Address 0x19), Autocalibration Timer
Table 27. Register CR30 (Address 0x1E), Attenuator
Bit
Description
Bit
Description
[7:0]
Autocalibration timer
7
Set to 0
6
Set to 0
[5:0]
Attenuator A5 to Attenuator A0
000000 = 0 dB
000001 = 1 dB
000010 = 2 dB
…
Table 24. Register CR27 (Address 0x1B), LO Monitor Output
and LO Selection
Bit
Description
7
Set to 0
6
Set to 0
011111 = 31 dB
110000 = 32 dB
110001 = 33 dB
…
111101 = 45 dB
111110 = 46 dB
111111 = 47 dB
5
4
3
2
Set to 0
Frequency range; set according to Table 6
Set to 0
Power up LO monitor output
0 = power down (default)
1 = power up
Monitor output power into 50 Ω
00 = −24 dBm (default)
01 = −18 dBm
[1:0]
Table 28. Register CR33 (Address 0x21), Revision Code1
Bit
Description
10 = −12 dBm
11 = −6 dBm
[7:0]
Revision code
1 Read-only register.
Table 25. Register CR28 (Address 0x1C), LO Selection
Bit
Description
7
Set to 0
6
Set to 0
5
Set to 0
4
Power down RFDIVIDER
0 = power up (default)
1 = power down
Set to 1
3
[2:0]
RFDIV1, set according to Table 6
1 Double-buffered. Loaded on a write to Register CR0.
Rev. B | Page 34 of 48
Data Sheet
ADRF6755
SUGGESTED POWER-UP SEQUENCE
22. Write 0xF0 to Register CR9. With the recommended loop
filter component values and RSET = 4.7 kΩ, as shown in
Figure 70, the charge pump current is set to 5 mA for a
loop bandwidth of 100 kHz.
23. Write 0x00 to Register CR8. Reserved register.
24. Write 0x0X to Register CR7. Set according to Equation 2 in
the Theory of Operation section. Also, set the MUXOUT
pin to tristate.
25. Write 0xXX to Register CR6. Set according to Equation 2
in the Theory of Operation section.
26. Write to Register CR5. Refer to the Reference Input Path
section, in particular Equation 1.
27. Write 0x01 to Register CR4. Reserved register.
28. Write 0000010X binary to Register CR3. Set according to
Equation 2 in the Theory of Operation section.
29. Write 0xXX to Register CR2. Set according to Equation 2
in the Theory of Operation section.
30. Write 0xXX to Register CR1. Set according to Equation 2
in the Theory of Operation section.
31. Write 0xXX to Register CR0. Set according to Equation 2
in the Theory of Operation section. Register CR0 must be
the last register written for all the double-buffered bit
writes to take effect.
INITIAL REGISTER WRITE SEQUENCE
After applying power to the part, perform the initial register write
sequence that follows. Note that Register CR33, Register CR32, and
Register CR31 are read-only registers. Also, note that all writable
registers should be written to on power-up. Refer to the Register
Map section for more details on all registers.
1. Write 0x00 to Register CR30. Set the attenuator to 0 dB gain.
2. Write 0x80 to Register CR29. The modulator is powered
down. The modulator is powered down by default to ensure
that no spurious signals can occur on the RF output when
the PLL is carrying out its first acquisition. The modulator
should be powered up only when the PLL is locked.
3. Write 0x0X to Register CR28. RFDIV depends on the value
of the LO frequency to be used and is set according to
Table 6. Note that Register CR28, Bit 3, is set to 1.
4. Write 0xX0 to Register CR27. Bit 4 depends on the LO
frequency to be used and is set according to Table 6.
5. Write 0x00 to Register CR26. Reserved register.
6. Write 0x64 to Register CR25, the autocalibration timer.
This setting applies for PFD = 40 MHz. For other PFDs,
refer to Equation 3 in the VCO Autocalibration section.
7. Write 0x18 to Register CR24. Enable autocalibration.
8. Write 0x70 to Register CR23. Enable the lock detector and
choose the recommended lock detect timing. This setting
applies to PFD = 40 MHz. For other PFDs, refer to the
Lock Detect (LDET) section in the Program Modes
section.
9. Write 0x80 to Register CR22. Reserved register.
10. Write 0x00 to Register CR21. Reserved register.
11. Write 0x00 to Register CR20. Reserved register.
12. Write 0x80 to Register CR19. Reserved register.
13. Write 0x60 to Register CR18. Reserved register.
14. Write 0x00 to Register CR17. Reserved register.
15. Write 0x00 to Register CR16. Reserved register.
16. Write 0x00 to Register CR15. Reserved register.
17. Write 0x80 to Register CR14. Stop LO when TXDIS = 1.
18. Write 0xE8 to Register CR13. This setting applies to PFD =
40 MHz. For other PFDs, refer to the Lock Detect (LDET)
32. Write to Register CR27, setting Bit 4 according to Table 6.
33. Monitor the LDET output or wait 170 μs to ensure that the
PLL is locked.
34. Write 0x81 to Register CR29. Power up the modulator. The
write to Register CR29 does not need to be followed by a write
to Register CR0 because this register is not double-buffered.
Example—Changing the LO Frequency
Following is an example of how to change the LO frequency
after the initialization sequence. Using an example in which
the PLL is locked to 2000 MHz, the following conditions apply:
•
•
fPFD = 40 MHz (assumed)
Divide ratio N = 50; therefore, INT = 50 decimal and
FRAC = 0
•
RFDIVIDER = divide-by-1. See Table 6.
section in the Program Modes
section.
Register CR28[2:0] = 000
Register CR27[4] = 1
19. Write 0x18 to Register CR12. Power up the PLL.
20. Write 0x00 to Register CR11. Reserved register.
21. Write to Register CR10. Refer to the Reference Input Path
section, in particular Equation 1.
The INT registers contain the following values:
Register CR7 = 0x00 and Register CR6 = 0x32
The FRAC registers contain the following values:
Register CR3 = 0x04, Register CR2 = 0x00,
Register CR1 = 0x00, and Register CR0 = 0x00
Rev. B | Page 35 of 48
ADRF6755
Data Sheet
To change the LO frequency to 925 MHz,
The FRAC registers contain the following values:
Register CR3 = 0x04, Register CR2 = 0x80,
Register CR1 = 0x00, and Register CR0 = 0x00
•
•
fPFD = 40 MHz (assumed)
Divide ratio N = 46.25; therefore, INT = 46 decimal and
FRAC = 8,388,608
Note that Register CR27 should be the last write in this
sequence, preceded by CR0. Writing to Register CR0 causes all
double-buffered registers to be updated, including the INT,
FRAC, and RFDIV registers, and starts a new PLL acquisition.
•
RFDIVIDER = divide-by-2. See Table 6.
Register CR28[2:0] = 001
Register CR27[4] = 0
The INT registers contain the following values:
Register CR7 = 0x00 and Register CR6 = 0x2E
Rev. B | Page 36 of 48
Data Sheet
ADRF6755
EVALUATION BOARD
SPI Interface
GENERAL DESCRIPTION
The SPI interface is provided by an additional SPD-S board. This
must be ordered with the ADRF6755 evaluation board. The system
demonstration platform (SDP) is a hardware and software platform
that provides a means to communicate from the PC to Analog
Devices products and systems that require digital control and/or
readback (see Figure 71).
The EVAL -ADRF6755SDZ evaluation board is designed to allow
the user to evaluate the performance of the ADRF6755. It contains
the following:
•
•
I/Q modulator with integrated fractional-N PLL and VCO
Connector to interface to a standard USB interface board
(SPD-S) that must be ordered with the EVAL -ADRF6755SDZ
board.
The SDP-S controller board connects to the PC via USB 2.0 and
to the ADRF6755 evaluation board via a small footprint, 120-pin
connector. The SDP-S (serial only interface) is a low cost, small
form factor, SDP controller board.
•
•
•
•
•
DC biasing and filter circuitry for the baseband inputs
Low-pass loop filter circuitry
An 80 MHz reference clock
Circuitry to monitor the LOMON outputs
SMA connectors for power supplies and the RF output
Baseband Inputs
The pair of I and Q baseband inputs are served by SMA inputs
(J2 to J5) so that they can be driven directly from an external
generator or a DAC board, both of which can also provide the
dc bias required. There is also an option to filter the baseband
inputs, although filtering may not be required, depending on
the quality of the baseband source.
The evaluation board is supplied with the associated driver
software to allow easy programming of the ADRF6755.
HARDWARE DESCRIPTION
For more information, refer to the circuit diagram in Figure 70.
Power Supplies
Loop Filter
A fourth-order loop filter is provided at the output of the charge
pump and is required to adequately filter noise from the Σ-Δ
modulator used in the N-divider. With the charge pump current
set to a value of 5 mA and using the on-chip VCO, the loop
bandwidth is approximately 100 kHz, and the phase margin is
55°. C0G capacitors are recommended for use in the loop filter
because they have low dielectric absorption, which is required
for fast and accurate settling time. The use of non-C0G capacitors
may result in a long tail being introduced into the settling time
transient.
An external 5 V supply, DUT +5 V (J14), drives both an on-chip
3.3 V regulator and the quadrature modulator.
The regulator feeds the VREG1 through VREG6 pins on the
chip with 3.3 V. These pins power the PLL circuitry.
The external reference clock generator should be driven by a
3.3 V supply. This supply should be connected via an SMA
connector, OSC +V (J15).
Recommended Decoupling for Supplies
The external DUT +5 V supply is decoupled initially by a 10 µF
capacitor and then further by a parallel combination of 100 nF
and 10 pF capacitors that are placed as close to the DUT as
possible for good local decoupling. The regulator output should
be decoupled by a parallel combination of 10 pF and 220 µF
capacitors. The 220 µF capacitor decouples broadband noise,
which leads to better phase noise and is recommended for best
performance. Case Size C 220 µF capacitors are used to minimize
area. Place a parallel combination of 100 nF and 10 pF capacitors
on each VREGx pin, as close to the pins as possible. The impedance
of these capacitors should be low and constant across a broad
frequency range. Surface-mount multilayered ceramic chip
(MLCC) Class II capacitors provide very low ESL and ESR, which
assist in decoupling supply noise effectively. They also provide
good temperature stability and good aging characteristics.
Reference Input
The reference input can be supplied by an 80 MHz Jauch clock
generator or by an external clock through the use of Connector
REFIN (J7). The frequency range of the PFD input is from 10 MHz
to 40 MHz; if the 80 MHz clock generator is used, the on-chip 5-bit
reference frequency divider or the divide-by-2 divider should be
used to set the PFD frequency to 40 MHz to optimize phase noise
performance.
LOMON Outputs
These pins are differential LO monitor outputs that provide a
replica of the internal LO frequency at 1× LO. The single-ended
power in a 50 Ω load can be programmed to −24 dBm, −18 dBm,
−12 dBm, or −6 dBm. These open-collector outputs must be
terminated to 3.3 V. B e caus e both outputs must be terminated
to 50 Ω, options are provided to terminate to 3.3 V using on-
board 50 Ω resistors or by series inductors (or a ferrite bead),
in which case the 50 Ω termination is provided by the measuring
instrument. If not used, these outputs should be tied to REGOUT.
Capacitance also changes vs. applied bias voltage. Larger case
sizes have less capacitance change vs. applied bias voltage and
have lower ESR but higher ESL. The 0603 size capacitors provide a
good compromise. X5R and X7R capacitors are examples of
these types of capacitors and are recommended for decoupling.
Rev. B | Page 37 of 48
ADRF6755
Data Sheet
CCOMPx Pins
Lock Detect (LDET)
The CCOMPx pins are internal compensation nodes that must
be decoupled to ground with a 100 nF capacitor.
Lock detect is a CMOS output that indicates the state of the
PLL. A high level indicates a locked condition, and a low level
indicates a loss of lock condition.
MUXOUT
TXDIS
MUXOUT is a test output that allows different internal nodes
to be monitored. It is a CMOS output stage that requires no
termination.
This input disables the RF output. It can be driven from an external
stimulus or simply connected high or low by Jumper J18.
RF Output (RFOUT)
RFOUT (J12) is the RF output of the ADRF6755.
Rev. B | Page 38 of 48
Data Sheet
ADRF6755
0 7 1
1
Figure 70. Applications Circuit Schematic
Rev. B | Page 39 of 48
ADRF6755
Data Sheet
Figure 71. Applications Circuit Schematic—SDP-S
Rev. B | Page 40 of 48
Data Sheet
ADRF6755
PCB ARTWORK
Component Placement
Figure 72. Evaluation Board, Top Side Component Placement
Figure 73. Evaluation Board, Bottom Side Component Placement
Rev. B | Page 41 of 48
ADRF6755
Data Sheet
PCB Layer Information
Figure 74. Evaluation Board, Top Side—Layer 1
Figure 75. Evaluation Board, Bottom Side—Layer 4
Rev. B | Page 42 of 48
Data Sheet
ADRF6755
Figure 76. Evaluation Board, Ground—Layer 2
Figure 77. Evaluation Board Power—Layer 3
Rev. B | Page 43 of 48
ADRF6755
Data Sheet
BILL OF MATERIALS
Table 29. Bill of Materials
Qty Reference Designator
Description
Manufacturer
Analog Devices
Jauch
Hirose
AVX
Part Number
1
DUT
ADRF6755, 56-lead 8 mm × 8 mm LFCSP
Crystal Oscillator, 80 MHz
Connector, FX8-120S-SV(21)
Capacitor, 10 µF, 25 V, tantalum, TAJ-C
Capacitor, 10 pF, 50 V, ceramic, C0G, 0402
ADRF6755ACPZ
O 80.0-JO75-B-3.3-2-T1
FEC 1324660
FEC 197518
FEC 8819564
1
Y2
1
2
CONN1
C1, C21
12
C4, C6, C8, C10, C12, C14, C16,
C18, C19, C48, C53, C55
Murata
14
C5, C7, C9, C11, C13, C15, C17,
C22, C47, C49 to C52, C54
C20
C30 to C33
C26
C24
C23, C25
C38, C39
C44, C46, C57
Capacitor, 100 nF, 25 V, X7R, ceramic, 0603
AVX
FEC 317287
FEC 197087
1
4
1
1
2
2
3
Capacitor, 220 µF, 6.3 V, tantalum, Case Size C AVX
Capacitor spacing, 0402 (do not install)
Capacitor, 1.2 nF, 50 V, C0G, ceramic, 0603
Capacitor, 47 nF, 50 V, C0G, ceramic, 1206
Capacitor, 560 pF, 50 V, NP0, ceramic, 0603
Capacitor, 1 nF, 50 V, C0G, ceramic, 0402
Capacitor, 100 pF, 50 V, C0G, ceramic, 0402
Kemet
FEC 1813421
FEC 8820201
FEC 1828912
FEC 8819556
FEC 8819572
Murata
Murata
Murata
Murata
11
2
J2 to J5, J7, J10 to J12, J14, J15, TXDIS SMA end launch connector
Johnson/Emerson 142-0701-851
J18, J21
Jumper, 3-pin + shunt
Harwin
FEC 148533 and
FEC 150411
2
2
5
2
1
2
1
2
3
4
3
2
1
1
L1, L2
L3, L4
Inductor, 20 nH, 0402, 5%
TE Connectivity
Vishay
Multicomp
FEC 1265424
FEC 1653752
FEC 1357983
Inductor, 10 µH, 0805, LQM series
Resistor, 0 Ω, 1/16 W, 1%, 0402
Resistor, 0402, spacing (do not install)
Resistor, 4.7 kΩ, 1/10 W, 1%, 0603
Resistor, 160 Ω, 1/16 W, 1%, 0603
Resistor, 150 Ω, 1/16 W, 1%, 0603
Resistor, 0603, spacing (do not install)
Resistor, 51 Ω, 1/16 W, 5%, 0402
Resistor, 330 Ω, 1/10 W, 5%, 0805
Resistor, 100 Ω, 1/10 W, 5%, 0805
Resistor, 100 kΩ, 1/16 W, 1%, 0603
LED, red, 0805, 1.8 V, low current
IC 24LC32A-I/MS EEPROM MSOP-8
R6 to R9, R36
R10, R11
R13
R12, R16
R15
Bourns
Multicomp
Multicomp
FEC 2008358
FEC 9330658
FEC 9330593
R62
R35, R44, R45
R48 to R51
R59 to R61
R63, R64
D1
Bourns
Vishay
Vishay
Multicomp
Rohm
FEC 2008358
FEC 1739223
FEC 1652907
FEC 9330402
FEC 1685056
FEC 133-4660
U1
Microchip
Rev. B | Page 44 of 48
Data Sheet
ADRF6755
OUTLINE DIMENSIONS
0.30
0.23
0.18
8.10
8.00 SQ
7.90
0.60 MAX
0.60
MAX
PIN 1
INDICATOR
43
42
56
1
0.50
BSC
PIN 1
INDICATOR
7.85
EXPOSED
PAD
6.65
6.50 SQ
6.35
7.75 SQ
7.65
29
28
14
15
0.50
0.40
0.30
0.20 MIN
BOTTOM VIEW
6.50 REF
TOP VIEW
0.80 MAX
0.65 TYP
1.00
0.85
0.80
12° MAX
FOR PROPER CONNECTION OF
THE EXPOSED PAD, REFER TO
THE PIN CONFIGURATION AND
FUNCTION DESCRIPTIONS
0.05 MAX
0.02 NOM
COPLANARITY
0.20 REF
0.08
SECTION OF THIS DATA SHEET.
SIDE VIEW
SEATING
PLANE
COMPLIANT TO JEDEC STANDARDS MO-220-VLLD-2
Figure 78. 56-Lead Lead Frame Chip Scale Package [LFCSP_VQ]
8 mm × 8 mm Body, Very Thin Quad
(CP-56-4)
Dimensions shown in millimeters
ORDERING GUIDE
Package
Option
Model1, 2
Temperature Range Package Description
ADRF6755ACPZ
ADRF6755ACPZ-R7
EVAL-ADRF6755SDZ
EVAL-SDP-CS1Z
EVAL-SDP-CB1Z
−40°C to +85°C
−40°C to +85°C
56-Lead Lead Frame Chip Scale Package [LFCSP_VQ], Tray
56-Lead Lead Frame Chip Scale Package [LFCSP_VQ], 7" Tape and Reel
Evaluation Board
SDP-S Controller Board; Interface to EVAL-ADRF6755SDZ (also required)
SDP-B Controller Board; Interface to EVAL-ADRF6755SDZ (alternative solution)
CP-56-4
CP-56-4
1 Z = RoHS Compliant Part.
2 Choose either EVAL-SDP-CS1Z or EVAL-SDP-CB1Z as EVAL-ADRF6755SDZ interface solution.
Rev. B | Page 45 of 48
ADRF6755
NOTES
Data Sheet
Rev. B | Page 46 of 48
Data Sheet
NOTES
ADRF6755
Rev. B | Page 47 of 48
ADRF6755
NOTES
Data Sheet
I2C refers to a communications protocol originally developed by Philips Semiconductors (now NXP Semiconductors).
©2012–2013 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D10465-0-4/13(B)
Rev. B | Page 48 of 48
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