AD9959/PCBZ1 [ADI]

4-Channel, 500 MSPS DDS with 10-Bit DACs; 4通道, 500 MSPS DDS ,10位DAC
AD9959/PCBZ1
型号: AD9959/PCBZ1
厂家: ADI    ADI
描述:

4-Channel, 500 MSPS DDS with 10-Bit DACs
4通道, 500 MSPS DDS ,10位DAC

数据分配系统
文件: 总44页 (文件大小:721K)
中文:  中文翻译
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4-Channel, 500 MSPS DDS  
with 10-Bit DACs  
AD9959  
Software-/hardware-controlled power-down  
Dual supply operation (1.8 V DDS core/3.3 V serial I/O)  
Multiple device synchronization  
Selectable 4× to 20× REFCLK multiplier (PLL)  
Selectable REFCLK crystal oscillator  
56-lead LFCSP package  
FEATURES  
4 synchronized DDS channels @ 500 MSPS  
Independent frequency/phase/amplitude control between  
channels  
Matched latencies for frequency/phase/amplitude changes  
Excellent channel-to-channel isolation (>65 dB)  
Linear frequency/phase/amplitude sweeping capability  
Up to 16 levels of frequency/phase/amplitude modulation  
(pin-selectable)  
4 integrated 10-bit digital-to-analog converters (DACs)  
Individually programmable DAC full-scale currents  
0.12 Hz or better frequency tuning resolution  
14-bit phase offset resolution  
APPLICATIONS  
Agile local oscillators  
Phased array radars/sonars  
Instrumentation  
Synchronized clocking  
RF source for AOTF  
10-bit output amplitude scaling resolution  
Serial I/O port interface (SPI) with enhanced data throughput  
FUNCTIONAL BLOCK DIAGRAM  
RECONSTRUCTED  
SINE WAVE  
10-BIT DAC  
(4)  
RECONSTRUCTED  
SINE WAVE  
500MSPS  
10-BIT DAC  
DDS CORES  
RECONSTRUCTED  
SINE WAVE  
10-BIT DAC  
10-BIT DAC  
MODULATION  
CONTROL  
RECONSTRUCTED  
SINE WAVE  
SYSTEM  
CLOCK  
SOURCE  
TIMING AND  
CONTROL  
REF CLOCK  
INPUT CIRCUITRY  
USER INTERFACE  
Figure 1.  
Rev. B  
Information furnished by Analog Devices is believed to be accurate and reliable. However, no  
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other  
rights of third parties that may result from its 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 and registeredtrademarks arethe property of their respective owners.  
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.  
Tel: 781.329.4700 www.analog.com  
Fax: 781.461.3113 ©2005–2008 Analog Devices, Inc. All rights reserved.  
 
AD9959  
TABLE OF CONTENTS  
Linear Sweep Mode.................................................................... 25  
Linear Sweep No-Dwell Mode ................................................. 26  
Sweep and Phase Accumulator Clearing Functions.............. 27  
Output Amplitude Control Mode............................................ 28  
Synchronizing Multiple AD9959 Devices................................... 29  
Automatic Mode Synchronization........................................... 29  
Manual Software Mode Synchronization................................ 29  
Manual Hardware Mode Synchronization.............................. 29  
Features .............................................................................................. 1  
Applications....................................................................................... 1  
Functional Block Diagram .............................................................. 1  
General Description......................................................................... 3  
Specifications..................................................................................... 4  
Absolute Maximum Ratings............................................................ 8  
ESD Caution.................................................................................. 8  
Pin Configuration and Function Descriptions............................. 9  
Typical Performance Characteristics ........................................... 11  
Application Circuits ....................................................................... 14  
Equivalent Input and Output Circuits......................................... 17  
Theory of Operation ...................................................................... 18  
DDS Core..................................................................................... 18  
Digital-to-Analog Converter .................................................... 18  
Modes of Operation ....................................................................... 19  
Channel Constraint Guidelines................................................ 19  
Power Supplies ............................................................................ 19  
Single-Tone Mode ...................................................................... 19  
Reference Clock Modes ............................................................. 20  
Scalable DAC Reference Current Control Mode ................... 21  
Power-Down Functions............................................................. 21  
Modulation Mode....................................................................... 21  
Modulation Using SDIO_x Pins for RU/RD........................... 24  
I/O_UPDATE, SYNC_CLK, and System Clock  
Relationships............................................................................... 30  
Serial I/O Port................................................................................. 31  
Overview ..................................................................................... 31  
Instruction Byte Description .................................................... 32  
Serial I/O Port Pin Description................................................ 32  
Serial I/O Port Function Description...................................... 32  
MSB/LSB Transfer Description ................................................ 32  
Serial I/O Modes of Operation................................................. 33  
Register Maps and Bit Descriptions............................................. 36  
Register Maps.............................................................................. 36  
Descriptions for Control Registers .......................................... 39  
Descriptions for Channel Registers ......................................... 41  
Outline Dimensions....................................................................... 44  
Ordering Guide .......................................................................... 44  
REVISION HISTORY  
7/08—Rev. A to Rev. B  
Added Equivalent Input and Output Circuits Section.............. 17  
Changes to Figure 35...................................................................... 21  
Changes to Setting the Slope of the Linear Sweep Section ....... 25  
Changes to Frequency Linear Sweep Example: AFP Bits = 10  
Section.............................................................................................. 26  
Changes to Figure 37...................................................................... 26  
Changes to Figure 38 and Figure 39............................................. 27  
Added Table 25 ............................................................................... 31  
Changes to Figure 41...................................................................... 31  
Changes to Figure 42...................................................................... 32  
Added Example Instruction Byte Section................................... 32  
Added Table 27 ............................................................................... 33  
Changes to Figure 46, Figure 47, Figure 48, and Figure 49....... 35  
Changes to Register Maps and Bit Descriptions Section .......... 36  
Added Endnote 1 to Table 30........................................................ 38  
Changes to Ordering Guide.......................................................... 44  
Added Pin Profile Toggle Rate Parameter in Table 1................... 6  
Changes to Figure 24...................................................................... 14  
Changes to Figure 31...................................................................... 17  
Changes to Reference Clock Input Circuitry Section................ 20  
Changes to Operation Section...................................................... 29  
Changes to Figure 40...................................................................... 30  
Changes to Serial Data I/O (SDIO_0, SDIO_1, SDIO_3)  
Section.............................................................................................. 32  
Changes to Table 38........................................................................ 43  
Added Exposed Pad Notation to Outline Dimensions ............. 44  
3/08—Rev. 0 to Rev. A  
Changes to Features.......................................................................... 1  
Inserted Figure 1............................................................................... 1  
Changes to Input Level Specification............................................. 4  
Changes to Layout ............................................................................ 8  
Changes to Table 3............................................................................ 9  
7/05—Revision 0: Initial Version  
Rev. B | Page 2 of 44  
AD9959  
GENERAL DESCRIPTION  
The AD9959 consists of four direct digital synthesizer (DDS)  
cores that provide independent frequency, phase, and amplitude  
control on each channel. This flexibility can be used to correct  
imbalances between signals due to analog processing, such as  
filtering, amplification, or PCB layout-related mismatches.  
Because all channels share a common system clock, they are  
inherently synchronized. Synchronization of multiple devices  
is supported.  
frequency tuning word, 14 bits of phase offset, and a 10-bit  
output scale multiplier.  
The DAC outputs are supply referenced and must be terminated  
into AVDD by a resistor or an AVDD center-tapped transformer.  
Each DAC has its own programmable reference to enable  
different full-scale currents for each channel.  
The DDS acts as a high resolution frequency divider with the  
REFCLK as the input and the DAC providing the output. The  
REFCLK input source is common to all channels and can be  
driven directly or used in combination with an integrated  
REFCLK multiplier (PLL) up to a maximum of 500 MSPS.  
The PLL multiplication factor is programmable from 4 to 20,  
in integer steps. The REFCLK input also features an oscillator  
circuit to support an external crystal as the REFCLK source.  
The crystal must be between 20 MHz and 30 MHz. The crystal  
can be used in combination with the REFCLK multiplier.  
The AD9959 can perform up to a 16-level modulation of fre-  
quency, phase, or amplitude (FSK, PSK, ASK). Modulation is  
performed by applying data to the profile pins. In addition, the  
AD9959 also supports linear sweep of frequency, phase, or  
amplitude for applications such as radar and instrumentation.  
The AD9959 serial I/O port offers multiple configurations to  
provide significant flexibility. The serial I/O port offers an SPI-  
compatible mode of operation that is virtually identical to the  
SPI operation found in earlier Analog Devices, Inc., DDS products.  
Flexibility is provided by four data pins (SDIO_0/SDIO_1/  
SDIO_2/SDIO_3) that allow four programmable modes of  
serial I/O operation.  
The AD9959 comes in a space-saving 56-lead LFCSP package.  
The DDS core (AVDD and DVDD pins) is powered by a 1.8 V  
supply. The digital I/O interface (SPI) operates at 3.3 V and  
requires DVDD_I/O (Pin 49) be connected to 3.3 V.  
The AD9959 uses advanced DDS technology that provides low  
power dissipation with high performance. The device incorporates  
four integrated, high speed 10-bit DACs with excellent wideband  
and narrow-band SFDR. Each channel has a dedicated 32-bit  
The AD9959 operates over the industrial temperature range of  
−40°C to +85°C.  
AD9959  
DDS CORE  
cos(x)  
CH0_IOUT  
CH0_IOUT  
Σ
Σ
Σ
Σ
Σ
Σ
Σ
Σ
Σ
Σ
Σ
DAC  
DAC  
DAC  
DAC  
32  
32  
32  
32  
32  
32  
32  
32  
15  
10  
10  
10  
10  
10  
10  
10  
10  
DDS CORE  
cos(x)  
CH1_IOUT  
CH1_IOUT  
15  
DDS CORE  
cos(x)  
CH2_IOUT  
CH2_IOUT  
15  
DDS CORE  
cos(x)  
CH3_IOUT  
CH3_IOUT  
Σ
15  
SCALABLE  
DAC REF  
CURRENT  
DAC_RSET  
32  
PHASE/  
ΔPHASE  
14  
AMP/  
ΔAMP  
10  
FTW  
DFTW  
SYNC_IN  
SYNC_OUT  
I/O_UPDATE  
TIMING AND CONTROL LOGIC  
PWR_DWN_CTL  
MASTER_RESET  
SYSTEM  
CLK  
CONTROL  
REGISTERS  
÷4  
SYNC_CLK  
SCLK  
CS  
SERIAL  
I/O  
PORT  
BUFFER  
REF CLOCK  
MULTIPLIER  
4× TO 20×  
REF_CLK  
REF_CLK  
CHANNE  
L
MUX  
SDIO_0  
SDIO_1  
SDIO_2  
SDIO_3  
REGISTE  
RS  
BUFFER/  
XTAL  
OSCILLATOR  
PROFILE  
REGISTERS  
1.8V  
1.8V  
AVDD  
DVDD  
P0 P1 P2 P3  
DVDD_I/O  
CLK_MODE_SEL  
Figure 2. Detailed Block Diagram  
Rev. B | Page 3 of 44  
 
AD9959  
SPECIFICATIONS  
AVDD and DVDD = 1.8 V 5ꢀ% DVDD_I/O = 3.3 V 5ꢀ% T = 25°C% RSET = 1.91 kΩ% external reference clock frequency = 500 MSPS  
(REFCLK multiplier bypassed), unless otherwise noted.  
Table 1.  
Parameter  
Min  
Typ  
Max  
Unit  
Test Conditions/Comments  
REFERENCE CLOCK INPUT CHARACTERISTICS  
Frequency Range  
See Figure 34 and Figure 35  
REFCLK Multiplier Bypassed  
REFCLK Multiplier Enabled  
Internal VCO Output Frequency Range  
VCO Gain Control Bit Set High1  
VCO Gain Control Bit Set Low1  
Crystal REFCLK Source Range  
Input Level  
Input Voltage Bias Level  
Input Capacitance  
Input Impedance  
1
10  
500  
125  
MHz  
MHz  
255  
100  
20  
500  
160  
30  
MHz  
MHz  
MHz  
mV  
V
200  
1000  
Measured at each pin (single-ended)  
1.15  
2
1500  
pF  
Ω
Duty Cycle with REFCLK Multiplier Bypassed  
Duty Cycle with REFCLK Multiplier Enabled  
CLK Mode Select (Pin 24) Logic 1 Voltage  
CLK Mode Select (Pin 24) Logic 0 Voltage  
DAC OUTPUT CHARACTERISTICS  
Resolution  
45  
35  
1.25  
55  
65  
1.8  
0.5  
%
%
V
V
1.8 V digital input logic  
1.8 V digital input logic  
Must be referenced to AVDD  
10  
10  
+10  
+2.5  
25  
Bits  
mA  
%FS  
%
μA  
LSB  
LSB  
pF  
Full-Scale Output Current  
Gain Error  
1.25  
10  
Channel-to-Channel Output Amplitude Matching Error −2.5  
Output Current Offset  
Differential Nonlinearity  
Integral Nonlinearity  
Output Capacitance  
1
0.5  
1.0  
3
Voltage Compliance Range  
Channel-to-Channel Isolation  
AVDD − 0.50  
65  
AVDD + 0.50  
V
dB  
DAC supplies tied together  
(see Figure 19)  
WIDEBAND SFDR  
The frequency range for wideband  
SFDR is defined as dc to Nyquist  
1 MHz to 20 MHz Analog Output  
20 MHz to 60 MHz Analog Output  
60 MHz to 100 MHz Analog Output  
100 MHz to 150 MHz Analog Output  
150 MHz to 200 MHz Analog Output  
NARROW-BAND SFDR  
dBc  
dBc  
dBc  
dBc  
dBc  
65  
62  
59  
56  
53  
1.1 MHz Analog Output ( 10 kHz)  
1.1 MHz Analog Output ( 50 kHz)  
1.1 MHz Analog Output ( 250 kHz)  
1.1 MHz Analog Output ( 1 MHz)  
15.1 MHz Analog Output ( 10 kHz)  
15.1 MHz Analog Output ( 50 kHz)  
15.1 MHz Analog Output ( 250 kHz)  
15.1 MHz Analog Output ( 1 MHz)  
40.1 MHz Analog Output ( 10 kHz)  
40.1 MHz Analog Output ( 50 kHz)  
40.1 MHz Analog Output ( 250 kHz)  
40.1 MHz Analog Output ( 1 MHz)  
75.1 MHz Analog Output ( 10 kHz)  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
90  
88  
86  
85  
90  
87  
85  
83  
90  
87  
84  
−82  
−87  
Rev. B | Page 4 of 44  
 
 
AD9959  
Parameter  
Min  
Typ  
−85  
−83  
−82  
−87  
−85  
−83  
−81  
−87  
−85  
−83  
−81  
Max  
Unit  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
dBc  
Test Conditions/Comments  
75.1 MHz Analog Output ( 50 kHz)  
75.1 MHz Analog Output ( 250 kHz)  
75.1 MHz Analog Output ( 1 MHz)  
100.3 MHz Analog Output ( 10 kHz)  
100.3 MHz Analog Output ( 50 kHz)  
100.3 MHz Analog Output ( 250 kHz)  
100.3 MHz Analog Output ( 1 MHz)  
200.3 MHz Analog Output ( 10 kHz)  
200.3 MHz Analog Output ( 50 kHz)  
200.3 MHz Analog Output ( 250 kHz)  
200.3 MHz Analog Output ( 1 MHz)  
PHASE NOISE CHARACTERISTICS  
Residual Phase Noise @ 15.1 MHz (fOUT  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
Residual Phase Noise @ 40.1 MHz (fOUT  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
Residual Phase Noise @ 75.1 MHz (fOUT  
@ 1 kHz Offset  
)
)
)
−150  
−159  
−165  
−165  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
−142  
−151  
−160  
−162  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
−135  
−146  
−154  
−157  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
Residual Phase Noise @ 100.3 MHz (fOUT  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
)
−134  
−144  
−152  
−154  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
Residual Phase Noise @ 15.1 MHz (fOUT  
with REFCLK Multiplier Enabled 5×  
)
)
)
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
Residual Phase Noise @ 40.1 MHz (fOUT  
with REFCLK Multiplier Enabled 5×  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
−139  
−149  
−153  
−148  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
−130  
−140  
−145  
−139  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
Residual Phase Noise @ 75.1 MHz (fOUT  
with REFCLK Multiplier Enabled 5×  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
−123  
−134  
−138  
−132  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
Rev. B | Page 5 of 44  
AD9959  
Parameter  
Min  
Typ  
Max  
Unit  
Test Conditions/Comments  
Residual Phase Noise @ 100.3 MHz (fOUT  
)
with REFCLK Multiplier Enabled 5×  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
−120  
−130  
−135  
−129  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
Residual Phase Noise @ 15.1 MHz (fOUT  
)
with REFCLK Multiplier Enabled 20×  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
−127  
−136  
−139  
−138  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
Residual Phase Noise @ 40.1 MHz (fOUT  
)
with REFCLK Multiplier Enabled 20×  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
−117  
−128  
−132  
−130  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
Residual Phase Noise @ 75.1 MHz (fOUT  
)
with REFCLK Multiplier Enabled 20×  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
@ 1 MHz Offset  
−110  
−121  
−125  
−123  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
Residual Phase Noise @ 100.3 MHz (fOUT  
)
with REFCLK Multiplier Enabled 20×  
@ 1 kHz Offset  
@ 10 kHz Offset  
@ 100 kHz Offset  
−107  
−119  
−121  
−119  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
@ 1 MHz Offset  
SERIAL PORT TIMING CHARACTERISTICS  
Maximum Frequency Serial Clock (SCLK)  
Minimum SCLK Pulse Width Low (tPWL  
Minimum SCLK Pulse Width High (tPWH  
200  
MHz  
ns  
ns  
ns  
ns  
)
1.6  
2.2  
2.2  
0
)
Minimum Data Setup Time (tDS  
Minimum Data Hold Time  
)
CS  
1.0  
12  
ns  
Minimum  
Setup Time (tPRE)  
Minimum Data Valid Time for Read Operation  
MISCELLANEOUS TIMING CHARACTERISTICS  
MASTER_RESET Minimum Pulse Width  
ns  
1
Min pulse width = 1 sync clock period  
Min pulse width = 1 sync clock period  
Rising edge to rising edge  
I/O_UPDATE Minimum Pulse Width  
1
4.8  
0
5.4  
0
2.5  
0
Minimum Setup Time (I/O_UPDATE to SYNC_CLK)  
Minimum Hold Time (I/O_UPDATE to SYNC_CLK)  
Minimum Setup Time (Profile Inputs to SYNC_CLK)  
Minimum Hold Time (Profile Inputs to SYNC_CLK)  
Minimum Setup Time (SDIO Inputs to SYNC_CLK)  
Minimum Hold Time (SDIO Inputs to SYNC_CLK)  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
Rising edge to rising edge  
Propagation Time Between REF_CLK and SYNC_CLK 2.25  
Profile Pin Toggle Rate  
3.5  
5.5  
2
Sync  
clocks  
CMOS LOGIC INPUTS  
VIH  
2.0  
V
VIL  
0.8  
12  
V
Logic 1 Current  
Logic 0 Current  
Input Capacitance  
3
−12  
2
μA  
μA  
pF  
Rev. B | Page 6 of 44  
AD9959  
Parameter  
Min  
Typ  
Max  
Unit  
Test Conditions/Comments  
CMOS LOGIC OUTPUTS  
1 mA load  
VOH  
VOL  
2.7  
V
V
0.4  
POWER SUPPLY  
Total Power Dissipation—All Channels On,  
Single-Tone Mode  
Total Power Dissipation—All Channels On,  
with Sweep Accumulator  
540  
580  
635  
680  
mW  
mW  
Dominated by supply variation  
Dominated by supply variation  
Total Power Dissipation—Full Power-Down  
IAVDD—All Channels On, Single-Tone Mode  
IAVDD—All Channels On, Sweep Accumulator, REFCLK  
Multiplier and 10-Bit Output Scalar Enabled  
13  
155  
160  
mW  
mA  
mA  
180  
185  
IDVDD—All Channels On, Single-Tone Mode  
IDVDD—All Channels On, Sweep Accumulator, REFCLK  
Multiplier and 10-Bit Output Scalar Enabled  
105  
125  
125  
145  
mA  
mA  
IDVDD_I/O  
40  
30  
mA  
mA  
mA  
mA  
IDVDD = read  
IDVDD = write  
IAVDD Power-Down Mode  
IDVDD Power-Down Mode  
0.7  
1.1  
DATA LATENCY (PIPELINE DELAY) SINGLE-TONE MODE2, 3  
Frequency, Phase, and Amplitude Words to DAC  
Output with Matched Latency Enabled  
Frequency Word to DAC Output with Matched  
Latency Disabled  
Phase Offset Word to DAC Output with Matched  
Latency Disabled  
Amplitude Word to DAC Output with Matched  
Latency Disabled  
29  
29  
25  
17  
SYSCLK  
s
SYSCLK  
s
SYSCLK  
s
SYSCLK  
s
DATA LATENCY (PIPELINE DELAY) MODULATION MODE3, 4  
Frequency Word to DAC Output  
34  
29  
21  
SYSCLK  
s
SYSCLK  
s
SYSCLK  
s
Phase Offset Word to DAC Output  
Amplitude Word to DAC Output  
DATA LATENCY (PIPELINE DELAY) LINEAR SWEEP MODE3, 4  
Frequency Rising/Falling Delta Tuning Word to DAC 41  
Output  
SYSCLK  
s
Phase Offset Rising/Falling Delta Tuning Word to  
DAC Output  
37  
SYSCLK  
s
Amplitude Rising/Falling Delta Tuning Word to DAC 29  
Output  
SYSCLK  
s
1 For the VCO frequency range of 160 MHz to 255 MHz, there is no guarantee of operation.  
2 Data latency is referenced to I/O_UPDATE.  
3 Data latency is fixed.  
4 Data latency is referenced to a profile change.  
Rev. B | Page 7 of 44  
 
AD9959  
ABSOLUTE MAXIMUM RATINGS  
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.  
Table 2.  
Parameter  
Maximum Junction Temperature  
DVDD_I/O (Pin 49)  
AVDD, DVDD  
Digital Input Voltage (DVDD_I/O = 3.3 V)  
Digital Output Current  
Storage Temperature Range  
Operating Temperature Range  
Lead Temperature (10 sec Soldering)  
θJA  
Rating  
150°C  
4 V  
2 V  
−0.7 V to +4 V  
5 mA  
–65°C to +150°C  
–40°C to +85°C  
300°C  
ESD CAUTION  
21°C/W  
2°C/W  
θJC  
Rev. B | Page 8 of 44  
 
AD9959  
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS  
SYNC_IN  
SYNC_OUT  
MASTER_RESET  
PWR_DWN_CTL  
AVDD  
1
2
3
4
5
6
7
8
9
PIN 1  
INDICATOR  
42 P2  
41 P1  
40 P0  
39 AVDD  
38 AGND  
37 AVDD  
36 CH1_IOUT  
35 CH1_IOUT  
34 AGND  
33 AVDD  
32 AGND  
31 AVDD  
30 CH0_IOUT  
29 CH0_IOUT  
AGND  
AD9959  
AVDD  
CH2_IOUT  
CH2_IOUT  
TOP VIEW  
(Not to Scale)  
AGND 10  
AVDD 11  
AGND 12  
CH3_IOUT 13  
14  
CH3_IOUT  
NC = NO CONNECT  
NOTES  
1. THE EXPOSED EPAD ON BOTTOM SIDE OF PACKAGE IS  
AN ELECTRICAL CONNECTION AND MUST BE  
SOLDERED TO GROUND.  
2. PIN 49 IS DVDD_I/O AND IS TIED TO 3.3V.  
Figure 3. Pin Configuration  
Table 3. Pin Function Descriptions  
Pin No.  
Mnemonic  
I/O1  
Description  
1
SYNC_IN  
I
Used to Synchronize Multiple AD9959 Devices. Connects to the SYNC_OUT pin of  
the master AD9959 device.  
2
3
SYNC_OUT  
O
I
Used to Synchronize Multiple AD9959 Devices. Connects to the SYNC_IN pin of the  
slave AD9959 devices.  
Active High Reset Pin. Asserting the MASTER_RESET pin forces the AD9959 internal  
registers to their default state, as described in the Register Maps and Bit Descriptions  
section.  
MASTER_RESET  
4
PWR_DWN_CTL  
AVDD  
I
I
External Power-Down Control.  
Analog Power Supply Pins (1.8 V).  
5, 7, 11, 15, 19, 21,  
26, 31, 33, 37, 39  
6, 10, 12, 16, 18, 20,  
25, 28, 32, 34, 38  
AGND  
I
Analog Ground Pins.  
45, 55  
44, 56  
8
DVDD  
DGND  
I
I
Digital Power Supply Pins (1.8 V).  
Digital Power Ground Pins.  
True DAC Output. Terminates into AVDD.  
Complementary DAC Output. Terminates into AVDD.  
True DAC Output. Terminates into AVDD.  
Complementary DAC Output. Terminates into AVDD.  
CH2_IOUT  
CH2_IOUT  
CH3_IOUT  
CH3_IOUT  
DAC_RSET  
O
O
O
O
I
9
13  
14  
17  
Establishes the Reference Current for All DACs. A 1.91 kΩ resistor (nominal) is  
connected from Pin 17 to AGND.  
22  
23  
REF_CLK  
REF_CLK  
I
I
Complementary Reference Clock/Oscillator Input. When the REF_CLK is operated  
in single-ended mode, this pin should be decoupled to AVDD or AGND with a  
0.1 μF capacitor.  
Reference Clock/Oscillator Input. When the REF_CLK is operated in single-ended  
mode, this is the input. See the Modes of Operation section for the reference clock  
configuration.  
Rev. B | Page 9 of 44  
 
AD9959  
Pin No.  
Mnemonic  
I/O1  
Description  
24  
CLK_MODE_SEL  
I
Control Pin for the Oscillator Section. Caution: Do not drive this pin beyond 1.8 V.  
When high (1.8 V), the oscillator section is enabled to accept a crystal as the  
REF_CLK source. When low, the oscillator section is bypassed.  
27  
LOOP_FILTER  
I
Connects to the external zero compensation network of the PLL loop filter.  
Typically, the network consists of a 0 Ω resistor in series with a 680 pF capacitor  
tied to AVDD.  
29  
CH0_IOUT  
CH0_IOUT  
CH1_IOUT  
CH1_IOUT  
P0 to P3  
O
O
O
O
I
Complementary DAC Output. Terminates into AVDD.  
True DAC Output. Terminates into AVDD.  
Complementary DAC Output. Terminates into AVDD.  
True DAC Output. Terminates into AVDD.  
Data pins used for modulation (FSK, PSK, ASK), to start/stop the sweep accumulators  
or used to ramp up/ramp down the output amplitude. The data is synchronous to  
the SYNC_CLK (Pin 54). The data inputs must meet the setup and hold time  
requirements of the SYNC_CLK. The functionality of these pins is controlled by the  
profile pin configuration (PPC) bits (FR1[14:12]).  
30  
35  
36  
40 to 43  
46  
I/O_UPDATE  
I
A rising edge transfers data from the serial I/O port buffer to active registers.  
I/O_UPDATE is synchronous to the SYNC_CLK (Pin 54). I/O_UPDATE must meet the  
setup and hold time requirements of the SYNC_CLK to guarantee a fixed pipeline  
delay of data to the DAC output; otherwise, a 1 SYNC_CLK period of pipeline  
uncertainty exists. The minimum pulse width is one SYNC_CLK period.  
47  
48  
CS  
I
I
Active Low Chip Select. Allows multiple devices to share a common I/O bus (SPI).  
SCLK  
Serial Data Clock for I/O Operations. Data bits are written on the rising edge of  
SCLK and read on the falling edge of SCLK.  
49  
50  
51, 52  
DVDD_I/O  
SDIO_0  
SDIO_1, SDIO_2  
I
3.3 V Digital Power Supply for SPI Port and Digital I/O.  
Data Pin SDIO_0 is dedicated to the serial port I/O only.  
Data Pin SDIO_1 and Data Pin SDIO_2 can be used for the serial I/O port or used to  
initiate a ramp-up/ramp-down (RU/RD) of the DAC output amplitude.  
I/O  
I/O  
53  
54  
SDIO_3  
I/O  
Data Pin SDIO_3 can be used for the serial I/O port or to initiate a ramp-up/ramp-down  
(RU/RD) of the DAC output amplitude. In single-bit or 2-bit modes, SDIO_3 is used  
for SYNC_I/O. If the SYNC_I/O function is not used, tie to ground or Logic 0. Do not  
let SDIO_3 float in single-bit or 2-bit modes.  
The SYNC_CLK runs at one-fourth the system clock rate; it can be disabled. I/O_UPDATE  
or data (Pin 40 to Pin 43) is synchronous to the SYNC_CLK. To guarantee a fixed pipeline  
delay of data to DAC output, I/O_UPDATE or data (Pin 40 to Pin 43) must meet the  
setup and hold time requirements to the rising edge of SYNC_CLK; otherwise, a 1  
SYNC_CLK period of uncertainty occurs.  
SYNC_CLK  
O
1 I = input, O = output.  
Rev. B | Page 10 of 44  
 
AD9959  
TYPICAL PERFORMANCE CHARACTERISTICS  
REF LVL  
0dBm  
DELTA 1 (T1)  
–69.47dB  
30.06012024MHz SWT  
RBW  
VBW  
20kHz  
20kHz  
1.6s  
RF ATT  
UNIT  
20dB  
DELTA 1 (T1)  
–71.73dB  
RBW  
VBW  
SWT  
20kHz  
20kHz  
1.6s  
RF ATT  
UNIT  
20dB  
dB  
REF LVL  
0dBm  
dB  
4.50901804MHz  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
A
A
1
1
1AP  
1AP  
1
1
START 0Hz  
25MHz/DIV  
STOP 250MHz  
START 0Hz  
25MHz/DIV  
STOP 250MHz  
Figure 7. Wideband SFDR, fOUT = 15.1 MHz, fCLK = 500 MSPS  
Figure 4. Wideband SFDR, fOUT = 1.1 MHz, fCLK = 500 MSPS  
DELTA 1 (T1)  
–62.84dB  
40.08016032MHz SWT  
RBW  
VBW  
20kHz  
20kHz  
1.6s  
RF ATT  
UNIT  
20dB  
dB  
REF Lv]  
0dBm  
DELTA 1 (T1)  
–60.13dB  
75.15030060MHz SWT  
RBW  
VBW  
20kHz  
20kHz  
1.6s  
RF ATT  
UNIT  
20dB  
dB  
REF LVL  
0dBm  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
1
A
A
1
1AP  
1AP  
1
1
START 0Hz  
25MHz/DIV  
STOP 250Hz  
START 0Hz  
25MHz/DIV  
STOP 250MHz  
Figure 5. Wideband SFDR, fOUT = 40.1 MHz, fCLK = 500 MSPS  
Figure 8. Wideband SFDR, fOUT = 75.1 MHz, fCLK = 500 MSPS  
DELTA 1 (T1)  
–59.04dB  
100.70140281MHz  
RBW  
VBW  
SWT  
20kHz  
20kHz  
1.6s  
RF ATT  
UNIT  
20dB  
dB  
REF LVL  
0dBm  
DELTA 1 (T1)  
–53.84dB  
–101.20240481MHz SWT  
RBW  
VBW  
20kHz  
20kHz  
1.6s  
RF ATT  
UNIT  
20dB  
dB  
REF LVL  
0dBm  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
A
A
1
1
1AP  
1AP  
1
1
START 0Hz  
25MHz/DIV  
STOP 250MHz  
START 0Hz  
25MHz/DIV  
STOP 250MHz  
Figure 6. Wideband SFDR, fOUT = 100.3 MHz, fCLK = 500 MSPS  
Figure 9. Wideband SFDR, fOUT = 200.3 MHz, fCLK = 500 MSPS  
Rev. B | Page 11 of 44  
 
AD9959  
REF LVL  
0dBm  
DELTA 1 (T1)  
–84.73dB  
254.50901604kHz  
RBW  
VBW  
SWT  
500Hz  
500Hz  
20s  
RF ATT  
UNIT  
20dB  
dB  
REF LVL  
0dBm  
DELTA 1 (T1)  
–84.86dB  
–200.40080160kHz  
RBW  
VBW  
SWT  
500Hz  
500Hz  
20s  
RF ATT  
UNIT  
20dB  
dB  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
1
A
A
1
1AP  
1AP  
1
1
CENTER 1.1MHz  
100kHz/DIV  
SPAN 1MHz  
CENTER 15.1MHz  
100kHz/DIV  
SPAN 1MHz  
Figure 10. NBSFDR, 1 MHz, fOUT = 1.1 MHz, fCLK = 500 MSPS  
Figure 13. NBSFDR, 1 MHz, fOUT = 15.1 MHz, fCLK = 500 MSPS  
REF LVL  
0dBm  
DELTA 1 (T1)  
–84.10dB  
120.24048096kHz SWT  
RBW  
VBW  
500Hz  
500Hz  
20s  
RF ATT  
UNIT  
20dB  
dB  
REF LVL  
0dBm  
DELTA 1 (T1)  
–86.03dB  
262.56513026kHz  
RBW  
VBW  
SWT  
500Hz  
500Hz  
20s  
RF ATT  
UNIT  
20dB  
dB  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
1
A
A
1
1AP  
1AP  
1
1
CENTER 40.1MHz  
100kHz/DIV  
SPAN 1MHz  
CENTER 75.1MHz  
100kHz/DIV  
SPAN 1MHz  
Figure 11. NBSFDR, 1 MHz, fOUT = 40.1 MHz, fCLK = 500 MSPS  
Figure 14. NBSFDR, 1 MHz, fOUT = 75.1 MHz, fCLK = 500 MSPS  
REF LVL  
0dBm  
DELTA 1 (T1)  
–82.63dB  
RBW  
VBW  
500Hz  
500Hz  
20s  
RF ATT  
UNIT  
20dB  
dB  
REF LVL  
0dBm  
DELTA 1 (T1)  
–83.72dB  
–400.80160321kHz  
RBW  
VBW  
SWT  
500Hz  
500Hz  
20s  
RF ATT  
UNIT  
20dB  
dB  
400.80160321kHz SWT  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
0
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
A
A
1
1
1AP  
1AP  
1
1
CENTER 100.3MHz  
100kHz/DIV  
SPAN 1MHz  
CENTER 200.3MHz  
100kHz/DIV  
SPAN 1MHz  
Figure 12. NBSFDR, 1 MHz, fOUT = 100.3 MHz, fCLK = 500 MSPS  
Figure 15. NBSFDR, 1 MHz, fOUT = 200. 3MHz, fCLK = 500 MSPS  
Rev. B | Page 12 of 44  
AD9959  
–100  
–110  
–120  
–130  
–140  
–150  
–160  
–170  
–60  
–65  
–70  
–75  
–80  
–85  
75.1MHz  
SINGLE DAC POWER PLANE  
100.3MHz  
40.1MHz  
SEPARATE DAC POWER PLANES  
75.3 100.3 125.3 150.3 175.3 200.3  
15.1MHz  
1k  
10  
100  
10k  
100k  
1M  
10M  
25.3  
50.3  
FREQUENCY OF COUPLING SPUR (MHz)  
FREQUENCY OFFSET (Hz)  
Figure 16. Residual Phase Noise (SSB) with fOUT = 15.1 MHz, 40.1 MHz,  
75.1 MHz, 100.3 MHz; fCLK = 500 MHz with REFCLK Multiplier Bypassed  
Figure 19. Channel Isolation at 500 MSPS Operation; Conditions are Channel  
of Interest Fixed at 110.3 MHz, the Other Channels Are Frequency Swept  
–70  
–80  
–90  
600  
4 CHANNELS ON  
500  
3 CHANNELS ON  
–100  
100.3MHz  
400  
–110  
2 CHANNELS ON  
300  
75.1MHz  
–120  
–130  
1 CHANNEL ON  
200  
–140  
40.1MHz  
–150  
15.1MHz  
100  
0
–160  
–170  
10  
100  
1k  
10k  
100k  
1M  
10M  
500  
450  
400  
350  
300  
250  
200  
150  
100  
50  
FREQUENCY OFFSET (Hz)  
REFERENCE CLOCK FREQUENCY (MHz)  
Figure 17. Residual Phase Noise (SSB) with fOUT = 15.1 MHz, 40.1 MHz,  
75.1 MHz, 100.3 MHz; fCLK = 500 MHz with REFCLK Multiplier = 5×  
Figure 20. Power Dissipation vs. Reference Clock Frequency vs. Channel(s)  
Power On/Off  
–70  
–80  
–90  
–45  
–50  
–100  
–110  
–120  
–130  
–140  
–150  
–160  
–170  
100.3MHz  
75.1MHz  
SFDR AVERAGED  
–55  
–60  
–65  
–70  
–75  
40.1MHz  
15.1MHz  
10  
100  
1k  
10k  
100k  
1M  
10M  
1.1  
15.1  
40.1  
75.1  
100.3  
200.3  
FREQUENCY OFFSET (Hz)  
fOUT (MHz)  
Figure 18. Residual Phase Noise (SSB) with fOUT = 15.1 MHz, 40.1 MHz,  
75.1 MHz,100.3 MHz; fCLK = 500 MHz with REFCLK Multiplier = 20×  
Figure 21. Averaged Channel SFDR vs. fOUT  
Rev. B | Page 13 of 44  
 
 
 
AD9959  
APPLICATION CIRCUITS  
PULSE  
ANTENNA  
RADIATING  
ELEMENTS  
AD9959  
FILTER  
FILTER  
FILTER  
FILTER  
FILTER  
FILTER  
FILTER  
FILTER  
CH0  
CH1  
CH2  
CH3  
LO  
REFCLK  
Figure 22. Phase Array Radar Using Precision Frequency/Phase Control from DDS in FMCW or Pulsed Radar Applications;  
DDS Provides Either Continuous Wave or Frequency Sweep  
AD8349  
I BASEBAND  
AD8348  
AD8347  
AD8346  
ADL5390  
CH2  
LO  
CH0  
IMAGE  
FREQUENCY  
RF OUTPUT  
AD9959  
CH1  
REFCLK  
CH3  
LO ±90  
DEGREES  
Q BASEBAND  
Figure 23. Single-Sideband-Suppressed Carrier Upconversion  
AD9510, AD9511, ADF4106  
÷
CHARGE  
PUMP  
LOOP  
FILTER  
PHASE  
VCO  
COMPARATOR  
REFERENCE  
÷
LPF  
REFCLK  
AD9959  
Figure 24. DDS in PLL Locking to Reference Offering Distribution with Fine Frequency and Delay Adjust Tuning  
Rev. B | Page 14 of 44  
 
 
AD9959  
AD9510  
CLOCK DISTRIBUTOR  
WITH  
CLOCK  
SOURCE  
DELAY EQUALIZATION  
REF_CLK  
AD9510  
SYNCHRONIZATION  
DELAY EQUALIZATION  
SYNC_OUT  
C1  
SYNC_IN  
S1AD9959  
DATA  
A1  
A2  
A3  
FPGA  
FPGA  
FPGA  
FPGA  
(MASTER)  
SYNC_CLK  
C2  
DATA  
S2AD9959  
(SLAVE 1)  
SYNC_CLK  
CENTRAL  
CONTROL  
C3  
S3AD9959  
DATA  
(SLAVE 2)  
SYNC_CLK  
C4  
DATA  
S4AD9959  
A4  
(SLAVE 3)  
SYNC_CLK  
A_END  
Figure 25. Synchronizing Multiple Devices to Increase Channel Capacity Using the AD9510 as a Clock Distributor for the Reference and SYNC_CLK  
OPTICAL FIBER CHANNEL  
WITH MULTIPLE DISCRETE  
WAVELENGTHS  
WDM  
SPLITTER  
SOURCE  
WDM SIGNAL  
INPUTS  
CH0  
CH0  
CH1  
CH2  
CH3  
AMP  
AMP  
AMP  
AMP  
CH1  
CH2  
ACOUSTIC OPTICAL  
TUNABLE FILTER  
AD9959  
REFCLK  
CH3  
OUTPUTS  
CH0 CH1 CH2 CH3  
SELECTABLE WAVELENGTH FROM EACH  
CHANNEL VIA DDS TUNING AOTF  
Figure 26. DDS Providing Stimulus for Acoustic Optical Tunable Filter  
CH0  
ADCMP563  
AD9959  
CH1  
REFCLK  
+
Figure 27. Agile Clock Source with Duty Cycle Control Using the Phase Offset Value in DDS to Change the DC Voltage to the Comparator  
Rev. B | Page 15 of 44  
AD9959  
PROGRAMMABLE 1 TO 32  
DIVIDER AND DELAY ADJUST  
CLOCK OUTPUT  
SELECTION(S)  
AD9515  
AD9514  
LVPECL  
LVDS  
CMOS  
AD9513  
AD9512  
n
n
CH0  
CH1  
AD9515  
AD9514  
AD9513  
AD9512  
LVPECL  
LVDS  
CMOS  
IMAGE  
IMAGE  
AD9959  
AD9515  
AD9514  
AD9513  
AD9512  
LVPECL  
LVDS  
CMOS  
REFCLK  
CH2  
CH3  
n
n
AD9515  
AD9514  
AD9513  
AD9512  
LVPECL  
LVDS  
CMOS  
n = DEPENDENT ON  
PRODUCT SELECTION  
Figure 28. Clock Generation Circuit Using the AD9512/AD9513/AD9514/AD9515 Series of Clock Distribution Chips  
Rev. B | Page 16 of 44  
AD9959  
EQUIVALENT INPUT AND OUTPUT CIRCUITS  
DVDD_I/O = 3.3V  
INPUT  
OUTPUT  
AVOID OVERDRIVING  
DIGITAL INPUTS.  
FORWARD BIASING  
DIODES MAY COUPLE  
DIGITAL NOISE ON  
POWER PINS.  
Figure 29. CMOS Digital Inputs  
CHx_IOUT  
CHx_IOUT  
TERMINATE OUTPUTS  
INTO AVDD. DO NOT  
EXCEED VOLTAGE  
COMPLIANCE OF  
OUTPUTS.  
Figure 30. DAC Outputs  
AVDD  
Z
Z
1.5k  
1.5kΩ  
REF_CLK  
AVDD  
REF_CLK  
AVDD  
AMP  
OSC  
OSC  
REF_CLK INPUTS ARE  
INTERNALLY BIASED AND  
NEED TO BE AC-COUPLED.  
OSC INPUTS ARE DC-COUPLED.  
REF_CLK  
Figure 31. REF_CLK/  
Inputs  
Rev. B | Page 17 of 44  
 
AD9959  
THEORY OF OPERATION  
DDS CORE  
DIGITAL-TO-ANALOG CONVERTER  
The AD9959 incorporates four 10-bit current output DACs.  
The DAC converts a digital code (amplitude) into a discrete  
analog quantity. The DAC current outputs can be modeled as a  
current source with high output impedance (typically 100 kΩ).  
Unlike many DACs, these current outputs require termination  
into AVDD via a resistor or a center-tapped transformer for  
expected current flow.  
The AD9959 has four DDS cores, each consisting of a 32-bit  
phase accumulator and phase-to-amplitude converter. Together,  
these digital blocks generate a digital sine wave when the phase  
accumulator is clocked and the phase increment value (frequency  
tuning word) is greater than 0. The phase-to-amplitude converter  
simultaneously translates phase information to amplitude  
information by a cos(θ) operation.  
Each DAC has complementary outputs that provide a combined  
full-scale output current (IOUT + IOUT). The outputs always sink  
The output frequency (fOUT) of each DDS channel is a function  
of the rollover rate of each phase accumulator. The exact  
relationship is given in the following equation:  
current, and their sum equals the full-scale current at any point  
in time. The full-scale current is controlled by means of an  
external resistor (RSET) and the scalable DAC current control  
bits discussed in the Modes of Operation section. The resistor,  
RSET, is connected between the DAC_RSET pin and analog  
ground (AGND). The full-scale current is inversely proportional  
to the resistor value as follows:  
(FTW)( fS )  
fOUT  
where:  
=
232  
fS is the system clock rate.  
FTW is the frequency tuning word and is 0 ≤ FTW ≤ 231.  
232 represents the phase accumulator capacity.  
18.91  
IOUT (max)  
RSET  
=
Because all four channels share a common system clock, they  
are inherently synchronized.  
The maximum full-scale output current of the combined DAC  
outputs is 15 mA, but limiting the output to 10 mA provides  
optimal spurious-free dynamic range (SFDR) performance.  
The DAC output voltage compliance range is AVDD + 0.5 V to  
AVDD − 0.5 V. Voltages developed beyond this range may cause  
excessive harmonic distortion. Proper attention should be paid  
to the load termination to keep the output voltage within its  
compliance range. Exceeding this range could potentially dam-  
age the DAC output circuitry.  
The DDS core architecture also supports the capability to phase  
offset the output signal, which is performed by the channel  
phase offset word (CPOW). The CPOW is a 14-bit register that  
stores a phase offset value. This value is added to the output of  
the phase accumulator to offset the current phase of the output  
signal. Each channel has its own phase offset word register. This  
feature can be used for placing all channels in a known phase  
relationship relative to one another. The exact value of phase  
offset is given by the following equation:  
LPF  
CHx_IOUT  
1:1  
POW  
Φ =  
× 360°  
214  
AVDD  
DAC  
50Ω  
CHx_IOUT  
Figure 32. Typical DAC Output Termination Configuration  
Rev. B | Page 18 of 44  
 
AD9959  
MODES OF OPERATION  
There are many combinations of modes (for example, single-  
tone, modulation, linear sweep) that the AD9959 can perform  
simultaneously. However, some modes require multiple data  
pins, which can impose limitations. The following guidelines  
can help determine if a specific combination of modes can be  
performed simultaneously by the AD9959.  
POWER SUPPLIES  
The AVDD and DVDD supply pins provide power to the DDS  
core and supporting analog circuitry. These pins connect to a  
1.8 V nominal power supply.  
The DVDD_I/O pin connects to a 3.3 V nominal power supply.  
All digital inputs are 3.3 V logic except for the CLK_MODE_SEL  
input. CLK_MODE_SEL (Pin 24) is an analog input and should  
be operated by 1.8 V logic.  
CHANNEL CONSTRAINT GUIDELINES  
Single-tone mode, two-level modulation mode, and linear  
sweep mode can be enabled on any channel and in any  
combination at the same time.  
SINGLE-TONE MODE  
Single-tone mode is the default mode of operation after a master  
reset signal. In this mode, all four DDS channels share a common  
address location for the frequency tuning word (Register 0x04)  
and phase offset word (Register 0x05). Channel enable bits are  
provided in combination with these shared addresses. As a  
result, the frequency tuning word and/or phase offset word can  
be independently programmed between channels (see the  
following Step 1 through Step 5). The channel enable bits do not  
require an I/O update to enable or disable a channel.  
Any one or two channels in any combination can perform  
four-level modulation. The remaining channels can be in  
single-tone mode.  
Any channel can perform eight-level modulation. The  
three remaining channels can be in single-tone mode.  
Any channel can perform 16-level direct modulation. The  
three remaining channels can be in single-tone mode.  
The RU/RD function can be used on all four channels in  
single-tone mode. See the Output Amplitude Control  
Mode section for the RU/RD function.  
When Profile Pin P2 and Profile Pin P3 are used for RU/RD,  
any two channels can perform two-level modulation with  
RU/RD or any two channels can perform linear frequency  
or phase sweep with RU/RD. The other two channels can  
be in single-tone mode.  
When Profile Pin P3 is used for RU/RD, any channel can  
be used in eight-level modulation with RU/RD. The other  
three channels can be in single-tone mode.  
When the SDIO_1, SDIO_2, and SDIO_3 pins are used for  
RU/RD, any one or two channels, any three channels, or  
all four channels can perform two-level modulation with  
RU/RD. Any channels not in the two-level modulation can  
be in single-tone mode.  
When the SDIO_1, SDIO_2, and SDIO_3 pins are used for  
RU/RD, any one or two channels can perform four-level  
modulation with RU/RD. Any channels not in four-level  
modulation can be in single-tone mode.  
When the SDIO_1, SDIO_2, and SDIO_3 pins are used for  
RU/RD, any channel can perform 16-level modulation with  
RU/RD. The other three channels can be in single-tone mode.  
Amplitude modulation, linear amplitude sweep modes,  
and the RU/RD function cannot operate simultaneously,  
but frequency and phase modulation can operate simulta-  
neously as the RU/RD function.  
See the Register Maps and Bit Descriptions section for a  
description of the channel enable bits in the channel select  
register (CSR, Register 0x00). The channel enable bits are  
enabled or disabled immediately after the CSR data byte is  
written.  
Address sharing enables channels to be written simultaneously,  
if desired. The default state enables all channel enable bits.  
Therefore, the frequency tuning word and/or phase offset word  
is common to all channels but written only once through the  
serial I/O port.  
The following steps present a basic protocol to program a  
different frequency tuning word and/or phase offset word for  
each channel using the channel enable bits.  
1. Power up the DUT and issue a master reset. A master reset  
places the part in single-tone mode and single-bit mode for  
serial programming operations (refer to the Serial I/O Modes  
of Operation section). Frequency tuning words and phase  
offset words default to 0 at this point.  
2. Enable only one channel enable bit (Register 0x00) and  
disable the other channel enable bits.  
3. Using the serial I/O port, program the desired frequency  
tuning word (Register 0x04) and/or the phase offset word  
(Register 0x05) for the enabled channel.  
4. Repeat Step 2 and Step 3 for each channel.  
5. Send an I/O update signal. After an I/O update, all  
channels should output their programmed frequency  
and/or phase offset value.  
Rev. B | Page 19 of 44  
 
 
AD9959  
The charge pump current in the PLL defaults to 75 μA. This  
setting typically produces the best phase noise characteristics.  
Increasing the charge pump current may degrade phase noise,  
but it decreases the lock time and changes the loop bandwidth.  
Single-Tone Mode—Matched Pipeline Delay  
In single-tone mode, the AD9959 offers matched pipeline delay  
to the DAC input for all frequency, phase, and amplitude changes.  
This avoids having to deal with different pipeline delays between  
the three input ports for such applications. The feature is enabled  
by asserting the matched pipe delays active bit found in the  
channel function register (CFR, Register 0x03). This feature  
is available in single-tone mode only.  
Enabling the on-chip oscillator for crystal operation is performed  
by driving CLK_MODE_SEL (Pin 24) to logic high (1.8 V  
logic). With the on-chip oscillator enabled, connection of an  
REF_CLK  
external crystal to the REF_CLK and  
inputs is made,  
producing a low frequency reference clock. The frequency of  
the crystal must be in the range of 20 MHz to 30 MHz.  
REFERENCE CLOCK MODES  
The AD9959 supports multiple reference clock configurations  
to generate the internal system clock. As an alternative to  
clocking the part directly with a high frequency clock source,  
the system clock can be generated using the internal, PLL-based  
reference clock multiplier. An on-chip oscillator circuit is also  
available for providing a low frequency reference signal by  
connecting a crystal to the clock input pins. Enabling these  
features allows the part to operate with a low frequency clock  
source and still provide a high update rate for the DDS and  
DAC. However, using the clock multiplier changes the output  
phase noise characteristics. For best phase noise performance,  
a clean, stable clock with a high slew is required (see Figure 17  
and Figure 18).  
Table 4 summarizes the clock modes of operation. See Table 1  
for more details.  
Reference Clock Input Circuitry  
The reference clock input circuitry has two modes of operation  
controlled by the logic state of Pin 24 (CLK_MODE_SEL). The  
first mode (logic low) configures as an input buffer. In this  
mode, the reference clock must be ac-coupled to the input due  
to internal dc biasing. This mode supports either differential  
or single-ended configurations. If single-ended mode is chosen,  
the complementary reference clock input (Pin 22) should be  
decoupled to AVDD or AGND via a 0.1 μF capacitor. Figure 33  
to Figure 35 exemplify typical reference clock configurations for  
the AD9959.  
Enabling the PLL allows multiplication of the reference clock  
frequency from 4× to 20×, in integer steps. The PLL multiplica-  
tion value is represented by a 5-bit multiplier value. These bits  
are located in Function Register 1 (FR1, Register 0x01), Bits[22:18]  
(see the Register Maps and Bit Descriptions section).  
1:1  
BALUN  
0.1µF  
50  
0.1µF  
REF_CLK  
PIN 23  
REFCLK  
SOURCE  
REF_CLK  
PIN 22  
When FR1[22:18] is programmed with values ranging from  
4 to 20 (decimal), the clock multiplier is enabled. The integer  
value in the register represents the multiplication factor. The  
system clock rate with the clock multiplier enabled is equal to  
the reference clock rate multiplied by the multiplication factor.  
If FR1[22:18] is programmed with a value less than 4 or greater  
than 20, the clock multiplier is disabled and the multiplication  
factor is effectively 1.  
Figure 33. Differential Coupling from Single-Ended Source  
The reference clock inputs can also support an LVPECL or  
PECL driver as the reference clock source.  
0.1µF  
REF_CLK  
PIN 23  
LVPECL/  
PECL  
TERMINATION  
DRIVER  
REF_CLK  
PIN 22  
0.1µF  
Figure 34. Differential Clock Source Hook-Up  
Whenever the PLL clock multiplier is enabled or the multiplica-  
tion value is changed, time should be allowed to lock the PLL  
(typically 1 ms).  
The second mode of operation (Pin 24 = logic high = 1.8 V)  
provides an internal oscillator for crystal operation. In this  
mode, both clock inputs are dc-coupled via the crystal leads  
and are bypassed. The range of crystal frequencies supported is  
from 20 MHz to 30 MHz. Figure 35 shows the configuration  
for using a crystal.  
Note that the output frequency of the PLL is restricted to a  
frequency range of 100 MHz to 500 MHz. However, there is a  
VCO gain control bit that must be used appropriately. The VCO  
gain control bit defines two ranges (low/high) of frequency  
output. The VCO gain control bit defaults to low (see Table 1  
for details).  
Table 4. Clock Configuration  
CLK_MODE_SEL, Pin 24 FR1[22:18] PLL Divider Ratio = M  
Crystal Oscillator Enabled  
System Clock (fSYSCLK  
)
Min/Max Freq. Range (MHz)  
100 < fSYSCLK < 500  
20 < fSYSCLK < 30  
100 < fSYSCLK < 500  
0 < fSYSCLK < 500  
High = 1.8 V Logic  
High = 1.8 V Logic  
Low  
4 ≤ M ≤ 20  
M < 4 or M > 20  
4 ≤ M ≤ 20  
Yes  
Yes  
No  
No  
fSYSCLK = fOSC × M  
fSYSCLK = fOSC  
fSYSCLK = fREFCLK × M  
fSYSCLK = fREFCLK  
Low  
M < 4 or M > 20  
Rev. B | Page 20 of 44  
 
 
 
 
 
AD9959  
When FR1[6] = 1 and the PWR_DWN_CTL input pin is high,  
the AD9959 is put into full power-down mode. In this mode, all  
functions are powered down. This includes the DAC and PLL,  
which take a significant amount of time to power up. When the  
PLL is bypassed, the PLL is shut down to conserve power.  
39pF  
39pF  
REF_CLK  
PIN 23  
25MHz  
XTAL  
REF_CLK  
PIN 22  
When the PWR_DWN_CTL input pin is high, the individual  
power-down bits (CFR[7:6] and FR1[7]) are invalid (don’t care)  
and unused. When the PWR_DWN_CTL input pin is low, the  
individual power-down bits control the power-down modes of  
operation.  
Figure 35.Crystal Input Configuration  
SCALABLE DAC REFERENCE CURRENT CONTROL  
MODE  
RSET is common to all four DACs. As a result, the full-scale  
currents are equal by default. The scalable DAC reference can  
be used to set the full-scale current of each DAC independent  
from one another. This is accomplished by using the register  
bits CFR[9:8]. Table 5 shows how each DAC can be individually  
scaled for independent channel control. This scaling provides  
for binary attenuation.  
Note that the power-down signals are all designed such that  
Logic 1 indicates the low power mode and Logic 0 indicates the  
powered-up mode.  
MODULATION MODE  
The AD9959 can perform 2-/4-/8-/16-level modulation of  
frequency, phase, or amplitude. Modulation is achieved by  
applying data to the profile pins. Each channel can be program-  
med separately, but the ability to modulate multiple channels  
simultaneously is constrained by the limited number of profile  
pins. For instance, 16-level modulation uses all four profile pins,  
which inhibits modulation for three channels.  
Table 5. DAC Full-Scale Current Control  
CFR[9:8]  
LSB Current State  
11  
01  
10  
00  
Full scale  
Half scale  
Quarter scale  
Eighth scale  
In addition, the AD9959 has the ability to ramp up or ramp  
down the output amplitude before, during, or after a modulation  
(FSK, PSK only) sequence. This is performed by using the 10-bit  
output scalar. If the RU/RD feature is desired, unused profile  
pins or unused SDIO_1/SDIO_2/SDIO_3 pins can be confi-  
gured to initiate the operation. See the Output Amplitude  
Control Mode section for more details of the RU/RD feature.  
POWER-DOWN FUNCTIONS  
The AD9959 supports an externally controlled power-down  
feature and the more common software programmable power-  
down bits found in previous Analog Devices DDS products.  
The software control power-down allows the input clock circui-  
try, the DAC, and the digital logic (for each separate channel) to  
be individually powered down via unique control bits (CFR[7:6]).  
These bits are not active when the externally controlled power-  
down pin (PWR_DWN_CTL) is high. When the input pin,  
PWR_DWN_CTL, is high, the AD9959 enters a power-down  
mode based on the FR1[6] bit. When the PWR_DWN_CTL  
input pin is low, the external power-down control is inactive.  
In modulation mode, each channel has its own set of control  
bits to determine the type (frequency, phase, or amplitude)  
of modulation. Each channel has 16 profile (channel word)  
registers for flexibility. Register 0x0A through Register 0x18  
are profile registers for modulation of frequency, phase, or  
amplitude. Register 0x04, Register 0x05, and Register 0x06  
are dedicated registers for frequency, phase, and amplitude,  
respectively. These registers contain the first frequency, phase  
offset, and amplitude word.  
When FR1[6] = 0 and the PWR_DWN_CTL input pin is high,  
the AD9959 is put into a fast recovery power-down mode. In  
this mode, the digital logic and the DAC digital logic are powered  
down. The DAC bias circuitry, PLL, oscillator, and clock input  
circuitry are not powered down.  
Frequency modulation has 32-bit resolution, phase modulation is  
14 bits, and amplitude is 10 bits. When modulating phase or  
amplitude, the word value must be MSB aligned in the profile  
(channel word) registers and the unused bits are don’t care bits.  
Rev. B | Page 21 of 44  
 
 
 
 
AD9959  
In modulation mode, the amplitude frequency phase (AFP)  
select bits (CFR[23:22]) and modulation level bits (FR1[9:8])  
are programmed to configure the modulation type and level  
(see Table 6 and Table 7). Note that the linear sweep enable bit  
must be set to Logic 0 in direct modulation mode.  
Because of the number of available channels and limited data  
pins, it is necessary to assign the profile pins and/or SDIO_1,  
SDIO_2, and SDIO_3 pins to a dedicated channel. This is con-  
trolled by the profile pin configuration (PPC) bits (FR1[14:12]).  
Each of the following modulation descriptions incorporates  
data pin assignments.  
Table 6. Modulation Type Configuration  
Two-Level Modulation—No RU/RD  
AFP Select  
(CFR[23:22])  
Linear Sweep Enable  
(CFR[14])  
Description  
The modulation level bits (FR1[9:8]) are set to 00 (two-level).  
The AFP select bits (CFR[23:22]) are set to the desired modulation  
type. The RU/RD bits (FR1[11:10]) and the linear sweep enable  
bit (CFR[14]) are disabled. Table 9 displays how the profile pins  
and channels are assigned.  
00  
01  
10  
11  
X
0
0
0
Modulation disabled  
Amplitude modulation  
Frequency modulation  
Phase modulation  
As shown in Table 9, only Profile Pin P0 can be used to modulate  
Channel 0. If frequency modulation is selected and Profile Pin  
P0 is Logic 0, Channel Frequency Tuning Word 0 (Register  
0x04) is chosen; if Profile Pin P0 is Logic 1, Channel Word 1  
(Register 0x0A) is chosen.  
Table 7. Modulation Level Selection  
Modulation Level (FR1[9:8])  
Description  
00  
01  
10  
11  
Two-level modulation  
Four-level modulation  
Eight-level modulation  
16-level modulation  
Four-Level Modulation—No RU/RD  
The modulation level bits are set to 01 (four-level). The AFP  
select bits (CFR[23:22]) are set to the desired modulation type.  
The RU/RD bits (FR1[11:10]) and the linear sweep enable bit  
(CFR[14]) are disabled. Note that the other two channels not  
being used should have their AFP select bits set to 00 due to the  
lack of profile pins. Table 10 displays how the profile pins and  
channels are assigned to each other.  
When modulating, the RU/RD function can be limited based  
on pins available for controlling the feature. The SDIO_x pins  
are for RU/RD only, not for modulation.  
Table 8. RU/RD Profile Pin Assignments  
Ramp-Up/Ramp-Down  
(RU/RD) (FR1[11:10])  
Description  
00  
01  
RU/RD disabled  
Only Profile Pin P2 and Profile Pin P3  
available for RU/RD operation  
For the conditions in Table 10, the profile (channel word)  
register chosen is based on the 2-bit value presented to Profile  
Pins [P0:P1] or Profile Pins [P2:P3].  
10  
11  
Only Profile Pin P3 available for RU/RD  
operation  
Only SDIO_1, SDIO_2, and SDIO_3  
pins available for RU/RD operation;  
this forces the serial I/O to be used  
only in 1-bit mode  
For example, if PPC = 010, [P0:P1] = 11, and [P2:P3] = 01, then  
the contents of the Channel Word 3 register of Channel 0 are  
presented to the output of Channel 0 and the contents of the  
Channel Word 1 register of Channel 3 are presented to the  
output of Channel 3.  
If the profile pins are used for RU/RD, Logic 0 is for ramp-up  
and Logic 1 is for ramp-down.  
Table 9. Profile Pin Channel Assignments  
Profile Pin Configuration (PPC) (FR1[14:12])  
P0  
P1  
P2  
P3  
Description  
XXX  
CH0  
CH1  
CH2  
CH3  
Two-level modulation, all channels, no RU/RD  
Table 10. Profile Pin and Channel Assignments  
Profile Pin Configuration (PPC) (FR1[14:12])  
P0  
P1  
P2  
P3  
Description  
000  
001  
010  
011  
100  
101  
CH0  
CH0  
CH0  
CH1  
CH1  
CH2  
CH0  
CH0  
CH0  
CH1  
CH1  
CH2  
CH1  
CH2  
CH3  
CH2  
CH3  
CH3  
CH1  
CH2  
CH3  
CH2  
CH3  
CH3  
Four-level modulation on CH0 and CH1, no RU/RD  
Four-level modulation on CH0 and CH2, no RU/RD  
Four-level modulation on CH0 and CH3, no RU/RD  
Four-level modulation on CH1 and CH2, no RU/RD  
Four-level modulation on CH1 and CH3, no RU/RD  
Four-level modulation on CH2 and CH3, no RU/RD  
Rev. B | Page 22 of 44  
 
 
 
 
AD9959  
Eight-Level Modulation—No RU/RD  
For the conditions in Table 12, the profile register chosen is  
based on the 4-bit value presented to Profile Pins [P0:P3].  
For example, if PPC = X11 and [P0:P3] = 1110, the contents of  
the Channel Word 14 register of Channel 3 is presented to the  
output of Channel 3.  
The modulation level bits (FR1[9:8]) are set to 10 (eight-level).  
The AFP select bits (CFR[23:22]) are set to a nonzero value.  
The RU/RD bits (FR1[11:10]) and the linear sweep enable bit  
(CFR[14]) are disabled. Note that the AFP select bits of the  
three channels not being used must be set to 00. Table 11 shows  
the assignment of profile pins and channels.  
Two-Level Modulation Using Profile Pins for RU/RD  
When the RU/RD bits = 01, Profile Pin P2 and Profile Pin P3  
are available for RU/RD. Note that only a modulation level of  
two is available in this mode. See Table 13 for available pin  
assignments.  
For the condition in Table 11, the choice of channel word registers  
is based on the 3-bit value presented to Profile Pins [P0:P2]. For  
example, if PPC = X10 and [P0:P2] = 111, the contents of the  
Channel Word 7 register of Channel 2 are presented to the output  
of Channel 2.  
Eight-Level Modulation Using a Profile Pin for RU/RD  
When the RU/RD bits = 10, Profile Pin P3 is available for RU/RD.  
Note that only a modulation level of eight is available in this  
mode. See Table 14 for available pin assignments.  
16-Level Modulation—No RU/RD  
The modulation level bits (FR1[9:8]) are set to 11 (16-level). The  
AFP select bits (CFR[23:22]) are set to the desired modulation  
type. The RU/RD bits (FR1[11:10]) and the linear sweep enable  
bit (CFR[14]) are disabled. The AFP select bits of the three  
channels not being used must be set to 00. Table 12 displays how  
the profile pins and channels are assigned.  
Table 11. Profile Pin and Channel Assignments for Eight-Level Modulation (No RU/RD)  
Profile Pin Config. (PPC)  
(FR1[14:12])  
P0  
P1  
P2  
P3  
X
X
X
X
Description  
X00  
X01  
X10  
X11  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
Eight-level modulation on CH0, no RU/RD  
Eight-level modulation on CH1, no RU/RD  
Eight-level modulation on CH2, no RU/RD  
Eight-level modulation on CH3, no RU/RD  
Table 12. Profile Pin and Channel Assignments for 16-Level Modulation (No RU/RD)  
Profile Pin Config. (PPC)  
(FR1[14:12])  
P0  
P1  
P2  
P3  
Description  
X00  
X01  
X10  
X11  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
16-level modulation on CH0, no RU/RD  
16-level modulation on CH1, no RU/RD  
16-level modulation on CH2, no RU/RD  
16-level modulation on CH3, no RU/RD  
Table 13. Profile Pin and Channel Assignments for Two-Level Modulation (RU/RD Enabled)  
Profile Pin Config. (PPC)  
(FR1[14:12])  
P0  
P1  
P2  
P3  
Description  
000  
001  
010  
011  
100  
101  
CH0  
CH0  
CH0  
CH1  
CH1  
CH2  
CH1  
CH2  
CH3  
CH2  
CH3  
CH3  
CH0 RU/RD  
CH0 RU/RD  
CH0 RU/RD  
CH1 RU/RD  
CH1 RU/RD  
CH2 RU/RD  
CH1 RU/RD  
CH2 RU/RD  
CH3 RU/RD  
CH2 RU/RD  
CH3 RU/RD  
CH3 RU/RD  
Two-level modulation on CH0 and CH1 with RU/RD  
Two-level modulation on CH0 and CH2 with RU/RD  
Two-level modulation on CH0 and CH3 with RU/RD  
Two-level modulation on CH1 and CH2 with RU/RD  
Two-level modulation on CH1 and CH3 with RU/RD  
Two-level modulation on CH2 and CH3 with RU/RD  
Table 14. Profile Pin and Channel Assignments for Eight-Level Modulation (RU/RD Enabled)  
Profile Pin Config. (PPC)  
(FR1[14:12])  
P0  
P1  
P2  
P3  
Description  
X00  
X01  
X10  
X11  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
CH0 RU/RD  
CH1 RU/RD  
CH2 RU/RD  
CH3 RU/RD  
Eight-level modulation on CH0 with RU/RD  
Eight-level modulation on CH1 with RU/RD  
Eight-level modulation on CH2 with RU/RD  
Eight-level modulation on CH3 with RU/RD  
Rev. B | Page 23 of 44  
 
 
 
 
AD9959  
For the configuration shown in Table 17, the profile (channel  
word) register is chosen based on the 2-bit value presented to  
Profile Pins [P1:P2] or [P3:P4].  
MODULATION USING SDIO_x PINS FOR RU/RD  
For RU/RD bits = 11, the SDIO_1, SDIO_2, and SDIO_3 pins  
are available for RU/RD. In this mode, modulation levels of 2, 4,  
and 16 are available. Note that the serial I/O port can be used only  
in 1-bit serial mode.  
For example, if PPC = 011, [P0:P1] = 11, and [P2:P3] = 01,  
the contents of the Channel Word 3 register of Channel 1 are  
presented to the output of Channel 1, and the contents of the  
Channel Word 1 register of Channel 2 are presented to the  
output of Channel 2. SDIO_1 and SDIO_2 provide the RU/RD  
function.  
Two-Level Modulation Using SDIO Pins for RU/RD  
Table 15. Profile Pin and Channel Assignments in Two-Level  
Modulation (RU/RD Enabled)  
Profile Pin Config. (PPC)  
(FR1[14:12])  
16-Level Modulation Using SDIO Pins for RU/RD  
P0  
P1  
P2  
P3  
The RU/RD bits = 11 (the SDIO_1 pin is available for RU/RD),  
and the level is set to 16. See the pin assignments shown in  
Table 18.  
XXX  
CH0  
CH1  
CH2  
CH3  
For the configuration in Table 15, each profile pin is dedicated  
to a specific channel. In this case, the SDIO_x pins can be used  
for the RU/RD function, as described in Table 16.  
For the configuration shown in Table 18, the profile (channel  
word) register is chosen based on the 4-bit value presented to  
Profile Pins [P0:P3]. For example, if PPC = X10 and [P0:P3] =  
1101, then the contents of the Channel Word 13 register of  
Channel 2 is presented to the output of Channel 2. The SDIO_1  
pin provides the RU/RD function.  
Four-Level Modulation Using SDIO Pins for RU/RD  
For RU/RD bits = 11 (the SDIO_1 and SDIO_2 pins are avail-  
able for RU/RD), the modulation level is set to 4. See Table 17  
for pin assignments, including SDIO_x pin assignments.  
Table 16. Channel and SDIO_1/SDIO_2/SDIO_3 Pin Assignments for RU/RD Operation  
SDIO_1  
SDIO_2  
SDIO_3  
Description  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Triggers the ramp-up function for CH0  
Triggers the ramp-down function for CH0  
Triggers the ramp-up function for CH1  
Triggers the ramp-down function for CH1  
Triggers the ramp-up function for CH2  
Triggers the ramp-down function for CH2  
Triggers the ramp-up function for CH3  
Triggers the ramp-down function for CH3  
Table 17. Channel and Profile Pin Assignments, Including SDIO_1/SDIO_2/SDIO_3 Pin Assignments for RU/RD Operation  
Profile Pin Configuration (PPC) (FR1[14:12])  
P0  
P1  
P2  
P3  
SDIO_1  
SDIO_2  
SDIO_3  
000  
001  
010  
011  
100  
101  
CH0  
CH0  
CH0  
CH1  
CH1  
CH2  
CH0  
CH0  
CH0  
CH1  
CH1  
CH2  
CH1  
CH2  
CH3  
CH2  
CH3  
CH3  
CH1  
CH2  
CH3  
CH2  
CH3  
CH3  
CH0 RU/RD  
CH0 RU/RD  
CH0 RU/RD  
CH1 RU/RD  
CH1 RU/RD  
CH2 RU/RD  
CH1 RU/RD  
CH2 RU/RD  
CH3 RU/RD  
CH2 RU/RD  
CH3 RU/RD  
CH3 RU/RD  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
Table 18. Channel and Profile Pin Assignments, Including SDIO_1 Pin Assignments for RU/RD Operation  
Profile Pin Configuration (PPC) (FR1[14:12])  
P0  
P1  
P2  
P3  
SDIO_1  
SDIO_2  
SDIO_3  
N/A  
N/A  
N/A  
N/A  
X00  
X01  
X10  
X11  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
CH0  
CH1  
CH2  
CH3  
CH0 RU/RD  
CH1 RU/RD  
CH2 RU/RD  
CH3 RU/RD  
N/A  
N/A  
N/A  
N/A  
Rev. B | Page 24 of 44  
 
 
 
 
 
AD9959  
LINEAR SWEEP MODE  
Setting the Slope of the Linear Sweep  
Linear sweep mode enables the user to sweep frequency, phase,  
or amplitude from a starting point (S0) to an endpoint (E0).  
The purpose of linear sweep mode is to provide better band-  
width containment compared to direct modulation by replacing  
greater instantaneous changes with more gradual, user-defined  
changes between S0 and E0.  
The slope of the linear sweep is set by the intermediate step size  
(delta-tuning word) between S0 and E0 and the time spent  
(sweep ramp rate word) at each step. The resolution of the  
delta-tuning word is 32 bits for frequency, 14 bits for phase, and  
10 bits for amplitude. The resolution for the delta ramp rate  
word is eight bits.  
In linear sweep mode, S0 is loaded into the Channel Word 0  
register (S0 is represented by one of three registers: Register 0x04,  
Register 0x05, or Register 0x06, depending on the type of sweep)  
and E0 is always loaded into Channel Word 1 (Register 0x0A).  
If E0 is configured for frequency sweep, the resolution is 32 bits,  
phase sweep is 14 bits, and amplitude sweep is 10 bits. When  
sweeping phase or amplitude, the word value must be MSB aligned  
in the Channel Word 1 register. The unused bits are don’t care  
bits. The profile pins are used to trigger and control the direction  
of the linear sweep for frequency, phase, and amplitude. All  
channels can be programmed separately for a linear sweep. In  
linear sweep mode, Profile Pin P0 is dedicated to Channel 0.  
Profile Pin P1 is dedicated to Channel 1, and so on.  
In linear sweep, each channel is assigned a rising delta word  
(RDW, Register 0x08) and a rising sweep ramp rate word  
(RSRR, Register 0x07). These settings apply when sweeping up  
toward E0. The falling delta word (FDW, Register 0x09) and  
falling sweep ramp rate (FSRR, Register 0x07) apply when  
sweeping down toward S0. Figure 36 displays a linear sweep up  
and then down using a profile pin. Note that the linear sweep  
no-dwell bit is disabled% otherwise, the sweep accumulator  
returns to 0 upon reaching E0.  
E0  
RDW  
Δf,p,a  
FDW  
Δf,p,a  
The AD9959 has the ability to ramp up or ramp down (RU/RD)  
the output amplitude (using the 10-bit output scalar) before and  
after a linear sweep. If the RU/RD feature is desired, unused  
profile pins or unused SDIO_1/SDIO_2/SDIO_3 pins can be  
configured for the RU/RD operation.  
RSRR  
FSRR  
Δt  
Δt  
S0  
PROFILE PIN  
To enable linear sweep mode for a particular channel, the AFP  
select bits (CFR[23:22]), the modulation level bits (FR1[9:8]),  
and the linear sweep enable bit (CFR[14]) are programmed.  
TIME  
Figure 36. Linear Sweep Parameters  
The AFP select bits determine the type of linear sweep to be  
performed. The modulation level bits must be set to 00 (two-  
level) for that specific channel (see Table 19 and Table 20)  
For a piecemeal or a nonlinear transition between S0 and E0,  
the delta-tuning words and ramp rate words can be repro-  
grammed during the transition to produce the desired response.  
Table 19. Linear Sweep Parameter to Sweep  
The formulas for calculating the step size of RDW or FDW for  
delta frequency, delta phase, or delta amplitude are as follows:  
AFP Select  
(CFR[23:22])  
Linear Sweep Enable  
(CFR[14])  
Description  
N/A  
Amplitude sweep  
Frequency sweep  
Phase sweep  
RDW  
00  
01  
10  
11  
1
1
1
1
Δf =  
× SYSCLK (Hz)  
232  
RDW  
ΔΦ =  
Δa =  
×360°  
214  
RDW  
Table 20. Modulation Level Assignments  
×1024 (DAC full-scale current)  
210  
Modulation Level (FR1[9:8])  
Description  
00 (Required in Linear Sweep)  
Two-level modulation  
Four-level modulation  
Eight-level modulation  
16-level modulation  
The formula for calculating delta time from RSRR or FSRR is  
t = RSRR ×1/SYNC _CLK  
01  
10  
11  
(
)
At 500 MSPS operation (SYNC_CLK = 125 MHz), the maxi-  
mum time interval between steps is 1/125 MHz × 256 = 2.048 μs.  
The minimum time interval is (1/125 MHz) × 1 = 8.0 ns.  
The sweep ramp rate block (timer) consists of a loadable 8-bit  
down counter that continuously counts down from the loaded  
value to 1. When the ramp rate timer equals 1, the proper ramp rate  
value is loaded and the counter begins counting down to 1 again.  
Rev. B | Page 25 of 44  
 
 
 
 
 
AD9959  
This load and countdown operation continues for as long as the  
timer is enabled. However, the count can be reloaded before  
reaching 1 by either of the following two methods:  
When the profile pin transitions from high to low, the FDW is  
applied to the input of the sweep accumulator and the FSRR bits  
are loaded into the sweep rate timer.  
The FDW accumulates at the rate given by the falling sweep ramp  
rate (FSRR) until the output is equal to the CFTW0 register  
(Register 0x04) value. The sweep is then complete, and the output  
is held constant in frequency.  
Method 1 is to change the profile pin. When the profile pin  
changes from Logic 0 to Logic 1, the rising sweep ramp rate  
(RSRR) register value is loaded into the ramp rate timer,  
which then proceeds to count down as normal. When the  
profile pin changes from Logic 1 to Logic 0, the falling sweep  
ramp rate (FSRR) register value is loaded into the ramp  
rate timer, which then proceeds to count down as normal.  
Method 2 is to set the CFR[14] bit and issue an I/O update.  
If sweep is enabled and CFR[14] is set, the ramp rate timer  
loads the value determined by the profile pin. If the profile  
pin is high, the ramp rate timer loads the RSRR% if the profile  
pin is low, the ramp rate timer loads FSRR.  
See Figure 37 for the linear sweep block diagram. Figure 39  
depicts a frequency sweep with no-dwell mode disabled. In this  
mode, the output follows the state of the profile pin. A phase or  
amplitude sweep works in the same manner.  
LINEAR SWEEP NO-DWELL MODE  
If the linear sweep no-dwell bit is set (CFR[15]), the rising sweep is  
started in an identical manner to the dwell linear sweep mode%  
that is, upon detecting Logic 1 on the profile input pin, the rising  
sweep action is initiated. The word continues to sweep up at the  
rate set by the rising sweep ramp rate at the resolution set by the  
rising delta word until it reaches the terminal value. Upon reaching  
the terminal value, the output immediately reverts to the starting  
point and remains until Logic 1 is detected on the profile pin.  
Frequency Linear Sweep Example: AFP Bits = 10  
In the following example, the modulation level bits (FR1[9:8]) = 00,  
the linear sweep enable bit (CFR[14]) = 1, and the linear sweep  
no-dwell bit (CFR[15]) = 0.  
In linear sweep mode, when the profile pin transitions from low  
to high, the RDW is applied to the input of the sweep accumulator  
and the RSRR register is loaded into the sweep rate timer.  
Figure 38 shows an example of the no-dwell mode. The points  
labeled A indicate where a rising edge is detected on the profile  
pin, and the points labeled B indicate where the AD9959 has  
determined that the output has reached E0 and reverts to S0.  
The falling sweep ramp rate bits (LSRR[15:8]) and the falling  
delta word bits (FDW[31:0]) are unused in this mode.  
The RDW accumulates at the rate given by the rising sweep  
ramp rate (RSRR) bits until the output is equal to the CW1  
register value. The sweep is then complete, and the output is  
held constant in frequency.  
SWEEP ACCUMULATOR  
SWEEP ADDER  
0
0
32  
32  
32  
32  
–1  
0
Z
MUX  
1
FDW  
RDW  
0
32  
0
MUX  
1
MUX  
1
MUX  
1
0
32  
PROFILE PIN  
CFTW0  
RAMP RATE TIMER:  
8-BIT LOADABLE DOWN COUNTER  
ACCUMULATOR RESET  
LOGIC  
LIMIT LOGICTO  
KEEP SWEEP BETWEEN  
S0 AND E0  
8
32  
PROFILE PIN  
CW1  
MUX  
1
0
RATE TIME  
LOAD CONTROL  
LOGIC  
FSRR RSRR  
Figure 37. Linear Sweep Block Diagram  
Rev. B | Page 26 of 44  
 
 
AD9959  
fOUT  
B
B
B
FTW1  
A
A
A
FTW0  
TIME  
SINGLE-TONE  
MODE  
P0 = 0  
P0 = 1  
P0 = 0  
P0 = 1  
P0 = 0  
P0 = 1  
LINEAR SWEEP MODE ENABLE—NO-DWELL BIT SET  
Figure 38. Linear Sweep Mode (No-Dwell Enabled)  
fOUT  
B
FTW1  
A
FTW0  
TIME  
SINGLE-TONE  
MODE  
LINEAR SWEEP MODE  
P0 = 1  
P0 = 0  
P0 = 0  
AT POINT A: LOAD RISING RAMP RATE REGISTER, APPLY RDW<31:0>  
AT POINT B: LOAD FALLING RAMP RATE REGISTER, APPLY FDW<31:0>  
Figure 39. Linear Sweep Mode (No-Dwell Disabled)  
Continuous Clear Bits  
SWEEP AND PHASE ACCUMULATOR CLEARING  
FUNCTIONS  
The continuous clear bits are static control signals that, when  
active high, hold the respective accumulator at 0 while the bit is  
active. When the bit goes low, the respective accumulator is  
allowed to operate.  
The AD9959 allows two different clearing functions. The first  
is a continuous zeroing of the sweep logic and phase accumula-  
tor (clear and hold). The second is a clear and release or automatic  
zeroing function. CFR[4] is the autoclear sweep accumulator bit  
and CFR[2] is the autoclear phase accumulator bit. The continuous  
clear bits are located in CFR, where CFR[3] clears the sweep  
accumulator and CFR[1] clears the phase accumulator.  
Clear and Release Bits  
The autoclear sweep accumulator bit, when set, clears and  
releases the sweep accumulator upon an I/O update or a change  
in the profile input pins. The autoclear phase accumulator bit,  
when set, clears and releases the phase accumulator upon an  
I/O update or a change in the profile pins. The automatic  
clearing function is repeated for every subsequent I/O update or  
change in profile pins until the clear and release bits are reset  
via the serial port.  
Rev. B | Page 27 of 44  
 
 
AD9959  
OUTPUT AMPLITUDE CONTROL MODE  
A special feature of this mode is that the maximum output  
amplitude allowed is limited by the contents of the amplitude  
scale factor (ACR[9:0]). This allows the user to ramp to a value  
less than full scale.  
The 10-bit scale factor (multiplier) controls the ramp-up and  
ramp-down (RU/RD) time of an on/off emission from the DAC.  
In burst transmissions of digital data, it reduces the adverse  
spectral impact of abrupt bursts of data. The multiplier can  
be bypassed by clearing the amplitude multiplier enable bit  
(ACR[12] = 0).  
Ramp Rate Timer  
The ramp rate timer is a loadable down counter that generates  
the clock signal to the 10-bit counter that generates the internal  
scale factor. The ramp rate timer is loaded with the value of the  
LSRR (Register 0x07) each time the counter reaches 1 (decimal).  
This load and countdown operation continues for as long as the  
timer is enabled unless the timer is forced to load before  
reaching a count of 1.  
Automatic and manual RU/RD modes are supported. The auto-  
matic mode generates a zero-scale up to a full-scale (10 bits)  
linear ramp at a rate determined by ACR (Register 0x06). The  
start and direction of the ramp can be controlled by either the  
profile pins or the SDIO_1/SDIO_2/SDIO_3 pins.  
Manual mode allows the user to directly control the output  
amplitude by manually writing to the amplitude scale factor  
value in the ACR (Register 0x06). Manual mode is enabled by  
setting ACR[12] = 1 and ACR[11] = 0.  
If the load ARR at I/O_UPDATE bit (ACR[10]) is set, the ramp  
rate timer is loaded at an I/O update, a change in profile input,  
or upon reaching a value of 1. The ramp timer can be loaded  
before reaching a count of 1 by three methods.  
Automatic RU/RD Mode Operation  
In the first method, the profile pins or the SDIO_1/  
SDIO_2/SDIO_3 pins are changed. When the control  
signal changes state, the ACR value is loaded into the ramp  
rate timer, which then proceeds to count down as normal.  
In the second method, the load ARR at I/O_UPDATE bit  
(ACR[10]) is set, and an I/O update is issued.  
Automatic RU/RD mode is active when both ACR[12] and  
ACR[11] are set. When automatic RU/RD is enabled, the scale  
factor is internally generated and applied to the multiplier input  
port for scaling the output. The scale factor is the output of a 10-bit  
counter that increments/decrements at a rate set by the 8-bit  
output ramp rate register. The scale factor increments if the  
external pin is high and decrements if the pin is low. The inter-  
nally generated scale factor step size is controlled by ACR[15:14].  
Table 21 describes the increment/decrement step size of the  
internally generated scale factor per ACR[15:14].  
The third method is to change from inactive automatic  
RU/RD mode to active automatic RU/RD mode.  
RU/RD Pin-to-Channel Assignment  
When all four channels are in single-tone mode, the profile pins  
are used for RU/RD operation.  
Table 21. Increment/Decrement Step Size Assignments  
When linear sweep and RU/RD are activated, the SDIO_1/  
SDIO_2/SDIO_3 pins are used for RU/RD operation.  
Increment/Decrement Step Size  
(ACR [15:14])  
Size  
In modulation mode, refer to the Modulation Mode section for  
pin assignments.  
00  
01  
10  
11  
1
2
4
8
Table 22. Profile Pin Assignments for RU/RD Operation  
Profile Pin  
RU/RD Operation  
P0  
P1  
P2  
P3  
CH0  
CH1  
CH2  
CH3  
Table 23. Channel Assignments of SDIO_1/SDIO_2/SDIO_3 Pins for RU/RD Operation  
Linear Sweep and RU/RD Modes Enabled  
Simultaneously  
Enable for CH0  
Enable for CH0  
Enable for CH1  
Enable for CH1  
Enable for CH2  
Enable for CH2  
Enable for CH3  
Enable for CH3  
SDIO_1 SDIO_2 SDIO_3 Ramp-Up/Ramp-Down Control Signal Assignment  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Ramp-up function for CH0  
Ramp-down function for CH0  
Ramp-up function for CH1  
Ramp-down function for CH1  
Ramp-up function for CH2  
Ramp-down function for CH2  
Ramp-up function for CH3  
Ramp-down function for CH3  
Rev. B | Page 28 of 44  
 
 
 
AD9959  
SYNCHRONIZING MULTIPLE AD9959 DEVICES  
The AD9959 allows easy synchronization of multiple AD9959  
devices. At power-up, the phase of SYNC_CLK can be offset  
between multiple devices. To correct for the offset and align the  
SYNC_CLK edges, there are three methods (one automatic mode  
and two manual modes) of synchronizing the SYNC_CLK edges.  
These modes force the internal state machines of multiple  
devices to a known state, which aligns the SYNC_CLK edges.  
Table 24. System Clock Offset (Delay) Assignments  
System Clock  
Offset (FR2[1:0])  
SYNC_OUT/SYNC_IN  
Propagation Delay  
00  
01  
10  
11  
0 ≤ delay ≤ 1  
1 ≤ delay ≤ 2  
2 ≤ delay ≤ 3  
3 ≤ delay ≤ 4  
In addition, the user must send a coincident I/O_UPDATE to  
multiple devices to maintain synchronization. Any mismatch in  
REF_CLK phase between devices results in a corresponding  
phase mismatch on the SYNC_CLK edges.  
Automatic Synchronization Status Bits  
If a slave device falls out of sync, the sync status bit is set high.  
The multidevice sync status bit (FR2[5]) can be read through  
the serial port. It is automatically cleared when read.  
AUTOMATIC MODE SYNCHRONIZATION  
The synchronization routine continues to operate regardless of  
the state of FR2[5]. FR2[5] can be masked by writing Logic 1 to  
the multidevice sync mask bit (FR2[4]). If FR2[5] is masked, it is  
held low.  
In automatic mode, multiple part synchronization is achieved  
by connecting the SYNC_OUT pin on the master device to the  
SYNC_IN pins of the slave devices. Devices are configured as  
master or slave through programming bits, accessible via the  
serial port.  
MANUAL SOFTWARE MODE SYNCHRONIZATION  
Manual software mode is enabled by setting the manual software  
sync bit (FR1[0]) to Logic 1 in a device. In this mode, the I/O  
update that writes the manual software sync bit to Logic 0 stalls  
the state machine of the clock generator for one system clock  
cycle. Stalling the clock generation state machine by one cycle  
changes the phase relationship of SYNC_CLK between devices  
by one system clock period (90°).  
A configuration for synchronizing multiple AD9959 devices in  
automatic mode is shown in the Application Circuits section. In  
this configuration, the AD9510 provides coincident REF_CLK  
and SYNC_OUT signals to all devices.  
Operation  
The first steps are to program the master and slave devices for  
their respective roles and then write the auto sync enable bit  
(FR2[7]) = 1. Enabling the master device is performed by writing  
its multidevice sync master enable bit in Function Register 2  
(FR2[6]) = 1. This causes the SYNC_OUT of the master device  
to output a pulse that has a pulse width equal to one system  
clock period and a frequency equal to one-fourth of the system  
clock frequency. Enabling devices as slaves is performed by  
writing FR2[6] = 0.  
Note that the user may have to repeat this process until the  
devices have their SYNC_CLK signals in phase. The SYNC_IN  
input can be left floating because it has an internal pull-up. The  
SYNC_OUT pin is not used.  
The synchronization is complete when the master and slave  
devices have their SYNC_CLK signals in phase.  
MANUAL HARDWARE MODE SYNCHRONIZATION  
Manual hardware mode is enabled by setting the manual hardware  
sync bit (FR1[1]) to Logic 1 in a device. In manual hardware  
synchronization mode, the SYNC_CLK stalls by one system  
clock cycle each time a rising edge is detected on the SYNC_IN  
input. Stalling the SYNC_CLK state machine by one cycle changes  
the phase relationship of SYNC_CLK between devices by one  
system clock period (90°).  
In automatic synchronizing mode, the slave devices sample  
SYNC_OUT pulses from the master device on the SYNC_IN  
of the slave devices, and a comparison of all state machines is  
made by the autosynchronization circuitry. If the slave devices  
state machines are not identical to the master, the slave devices  
state machines are stalled for one system clock cycle. This proce-  
dure synchronizes the slave devices within three SYNC_CLK  
periods.  
Note that the user may have to repeat the process until the  
devices have their SYNC_CLK signals in phase. The SYNC_IN  
input can be left floating because it has an internal pull-up. The  
SYNC_OUT is not used.  
Delay Time Between SYNC_OUT and SYNC_IN  
When the delay between SYNC_OUT and SYNC_IN exceeds  
one system clock period, the system clock offset bits (FR2[1:0]) are  
used to compensate. The default state of these bits is 00, which  
implies that the SYNC_OUT of the master and the SYNC_IN of  
the slave have a propagation delay of less than one system clock  
period. If the propagation time is greater than one system clock  
period, the time should be measured and the appropriate offset  
programmed. Table 24 describes the delays required per system  
clock offset value.  
The synchronization is complete when the master and slave  
devices have their SYNC_CLK signals in phase.  
Rev. B | Page 29 of 44  
 
 
 
 
AD9959  
If the setup time between these signals is met, then constant  
latency (pipeline) to the DAC output exists. For example, if  
repetitive changes to phase offset via the SPI port is desired, the  
latency of those changes to the DAC output is constant% otherwise,  
a time uncertainty of one SYNC_CLK period is present.  
I/O_UPDATE, SYNC_CLK, AND SYSTEM CLOCK  
RELATIONSHIPS  
I/O_UPDATE and SYNC_CLK are used together to transfer  
data from the serial I/O buffer to the active registers in the  
device. Data in the buffer is inactive.  
The I/O_UPDATE is essentially oversampled by the SYNC_CLK.  
Therefore, I/O_UPDATE must have a minimum pulse width  
greater than one SYNC_CLK period.  
SYNC_CLK is a rising edge active signal. It is derived from  
the system clock and a divide-by-4 frequency divider. The  
SYNC_CLK, which is externally provided, can be used to  
synchronize external hardware to the AD9959 internal clocks.  
The timing diagram shown in Figure 40 depicts when data in  
the buffer is transferred to the active registers.  
I/O_UPDATE initiates the start of a buffer transfer. It can be  
sent synchronously or asynchronously relative to the SYNC_CLK.  
SYSCLK  
A
B
SYNC_CLK  
I/O_UPDATE  
DATA IN  
REGISTERS  
N
N + 1  
N – 1  
DATA IN  
I/O BUFFERS  
N
N + 1  
N + 2  
THE DEVICE REGISTERS AN I/O UPDATE AT POINT A. THE DATA IS TRANSFERRED FROM THE ASYNCHRONOUSLY LOADED I/O BUFFERS AT POINT B.  
Figure 40. I/O_UPDATE Transferring Data from I/O Buffer to Active Registers  
Rev. B | Page 30 of 44  
 
 
AD9959  
SERIAL I/O PORT  
Phase 2 of the I/O cycle consists of the actual data transfer  
OVERVIEW  
(write/read) between the serial port controller and the serial  
port buffer. The number of bytes transferred during this phase  
of the communication cycle is a function of the register being  
accessed. The actual number of additional SCLK rising edges  
required for the data transfer and instruction byte depends on  
the number of bytes in the register and the serial I/O mode of  
operation.  
The AD9959 serial I/O port offers multiple configurations to  
provide significant flexibility. The serial I/O port offers an SPI-  
compatible mode of operation that is virtually identical to the  
SPI operation found in earlier Analog Devices DDS products.  
The flexibility is provided by four data pins (SDIO_0, SDIO_1,  
SDIO_2, SDIO_3) that allow four programmable modes of  
serial I/O operation.  
For example, when accessing Function Register 1 (FR1), which  
is three bytes wide, Phase 2 of the I/O cycle requires that three  
bytes be transferred. After transferring all data bytes per the  
instruction byte, the communication cycle is completed for that  
register.  
Three of the four data pins (SDIO_1, SDIO_2, SDIO_3) can be  
used for functions other than serial I/O port operation. These pins  
can also be used to initiate a ramp-up or ramp-down (RU/RD)  
of the 10-bit amplitude output scalar. In addition, SDIO_3 can  
be used to provide the SYNC_I/O function that resynchronizes  
the serial I/O port controller if it is out of proper sequence.  
At the completion of a communication cycle, the AD9959 serial  
port controller expects the next set of rising SCLK edges to be  
the instruction byte for the next communication cycle. All data  
written to the AD9959 is registered on the rising edge of SCLK.  
Data is read on the falling edge of SCLK (see Figure 43 through  
Figure 49). The timing specifications for Figure 41 and Figure 42  
are described in Table 25.  
The maximum speed of the serial I/O port SCLK is 200 MHz,  
but the four data pins (SDIO_0, SDIO_1, SDIO_2, SDIO_3)  
can be used to further increase data throughput. The maximum  
data throughput using all the SDIO pins (SDIO_0, SDIO_1,  
SDIO_2, SDIO_3) is 800 Mbps.  
Note that all channels share Register 0x03 to Register 0x18, which  
are shown in the Register Maps and Bit Descriptions section.  
This address sharing enables all four DDS channels to be written  
to simultaneously. For example, if a common frequency tuning  
word is desired for all four channels, it can be written once  
through the serial I/O port to all four channels. This is the  
default mode of operation (all channels enabled). To enable  
each channel to be independent, the four channel enable bits  
found in the channel select register (CSR, Register 0x00) must  
be used.  
tPRE  
tSCLK  
CS  
tDSU  
tSCLKPWL  
SCLK  
tSCLKPWH  
tDHLD  
SDIO_x  
Figure 41. Setup and Hold Timing for the Serial I/O Port  
CS  
There are effectively four sets or copies of addresses (Register 0x03  
to Register 0x18) that the channel enable bits can access to provide  
channel independence. See the Descriptions for Control Registers  
section for further details of programming channels that are  
common to or independent from each other. To properly read  
back Register 0x03 to Register 0x18, the user must enable only  
one channel enable bit at a time.  
SCLK  
SDIO_x  
SDO (SDIO_2)  
tDV  
Figure 42. Timing Diagram for Data Read for Serial I/O Port  
Table 25. Timing Specifications  
Serial operation of the AD9959 occurs at the register level,  
not the byte level% that is, the controller expects that all bytes  
contained in the register address are accessed. The SYNC_I/O  
function can be used to abort an I/O operation, thereby allowing  
fewer than all bytes to be accessed. This feature can be used to  
program only a part of the addressed register. Note that only  
completed bytes are affected.  
Parameter Min Unit  
Description  
tPRE  
1.0  
5.0  
2.2  
2.2  
1.6  
0
ns min CS setup time  
tSCLK  
tDSU  
tSCLKPWH  
tSCLKPWL  
tDHLD  
tDV  
ns min Period of serial data clock  
ns min Serial data setup time  
ns min Serial data clock pulse width high  
ns min Serial data clock pulse width low  
ns min Serial data hold time  
ns min Data valid time  
There are two phases to a serial communications cycle. Phase 1  
is the instruction cycle, which writes the instruction byte into  
the AD9959. Each bit of the instruction byte is registered on  
each corresponding rising edge of SCLK. The instruction byte  
defines whether the upcoming data transfer is a write or read  
operation. The instruction byte contains the serial address of  
the address register.  
12  
Rev. B | Page 31 of 44  
 
 
 
 
AD9959  
Each set of communication cycles does not require an I/O update  
to be issued. The I/O update transfers data from the I/O port  
buffer to active registers. The I/O update can be sent for each  
communication cycle or can be sent when all serial operations  
are complete. However, data is not active until an I/O update is  
sent, with the exception of the channel enable bits in the channel  
select register (CSR). These bits do not require an I/O update to  
be enabled.  
this pin. The SDO function is not available in 2-bit or 4-bit serial  
I/O modes.  
SYNC_I/O  
The SYNC_I/O function is available in 1-bit and 2-bit modes.  
SDIO_3 serves as the SYNC_I/O pin when this function is  
active. Bits CSR[2:1] control the configuration of this pin.  
Otherwise, the SYNC_I/O function is used to synchronize the  
I/O port state machines without affecting the addressable register  
contents. An active high input on the SYNC_I/O (SDIO_3) pin  
causes the current communication cycle to abort. After SDIO_3  
returns low (Logic 0), another communication cycle can begin,  
starting with the instruction byte write. The SYNC_I/O function is  
not available in 4-bit serial I/O mode.  
INSTRUCTION BYTE DESCRIPTION  
The instruction byte contains the following information:  
MSB  
D7  
LSB  
D0  
A0  
D6  
x1  
D5  
x1  
D4  
D3  
D2  
D1  
R/W  
A4  
A3  
A2  
A1  
MSB/LSB TRANSFER DESCRIPTION  
1 x = don’t care bit.  
The AD9959 serial port can support both most significant bit  
(MSB) first or least significant bit (LSB) first data formats. This  
functionality is controlled by CSR[0]. MSB first is the default  
mode. When CSR[0] is set high, the AD9959 serial port is in  
LSB first format. The instruction byte must be written in the  
format indicated by CSR[0], that is, if the AD9959 is in LSB first  
mode, the instruction byte must be written from LSB to MSB. If  
the AD9959 is in MSB first mode (default), the instruction byte  
must be written from MSB to LSB.  
W
Bit D7 of the instruction byte (R/ ) determines whether a read  
or write data transfer occurs after the instruction byte write. A  
logic high indicates a read operation. A logic low indicates a  
write operation.  
Bit D4 to Bit D0 of the instruction byte determine which register is  
accessed during the data transfer portion of the communication  
cycle. The internal byte addresses are generated by the AD9959.  
SERIAL I/O PORT PIN DESCRIPTION  
Example Operation  
Serial Data Clock (SCLK)  
To write Function Register 1 (FR1, Register 0x01) in MSB first  
format, apply an instruction byte of 00000001 starting with the  
MSB (in the following example instruction byte, the MSB is  
D7). From this instruction, the internal controller recognizes a  
write transfer of three bytes starting with the MSB, FR1[23].  
Bytes are written on each consecutive rising SCLK edge until  
Bit 0 is transferred. When the last data bit is written, the I/O  
communication cycle is complete and the next byte is considered  
an instruction byte.  
The serial data clock pin is used to synchronize data to and from  
the internal state machines of the AD9959. The maximum  
SCLK toggle frequency is 200 MHz.  
CS  
Chip Select (  
)
The chip select pin allows more than one AD9959 device to be  
on the same set of serial communications lines. The chip select  
is an active low enable pin. SDIO_x inputs go to a high imped-  
CS  
CS  
ance state when  
communication cycle, that cycle is suspended until  
CS  
is high. If  
is driven high during any  
Example Instruction Byte1  
CS  
is  
MSB  
D7  
0
LSB  
D0  
1
reactivated low. The  
pin can be tied low in systems that  
maintain control of SCLK.  
D5  
D6  
D4  
D3  
D2  
D1  
0
0
0
0
0
0
Serial Data I/O (SDIO_0, SDIO_1, SDIO_3)  
1 Note that the bit values are for example purposes only.  
Of the four SDIO pins, only the SDIO_0 pin is a dedicated SDIO  
pin. SDIO_1, SDIO_2, and SDIO_3 can also be used to ramp  
up/ramp down the output amplitude. Bits[2:1] in the channel  
select register (CSR, Register 0x00) control the configuration  
of these pins. See the Serial I/O Modes of Operation for more  
information.  
To write Function Register 1 (FR1) in LSB first format, apply an  
instruction byte of 00000001, starting with the LSB bit (in the  
preceding example instruction byte, the LSB is D0). From this  
instruction, the internal controller recognizes a write transfer of  
three bytes, starting with the LSB, FR1[0]. Bytes are written on  
each consecutive rising SCLK edge until Bit 23 is transferred.  
When the last data bit is written, the I/O communication cycle is  
complete and the next byte is considered an instruction byte.  
SERIAL I/O PORT FUNCTION DESCRIPTION  
Serial Data Out (SDO)  
The SDO function is available in single-bit (3-wire) mode only.  
In SDO mode, data is read from the SDIO_2 pin for protocols  
that use separate lines for transmitting and receiving data (see  
Table 26 for pin configuration options). Bits[2:1] in the channel  
select register (CSR, Register 0x00) control the configuration of  
Rev. B | Page 32 of 44  
 
 
 
AD9959  
In single-bit serial mode, 2-wire interface operation, the  
SERIAL I/O MODES OF OPERATION  
SDIO_0 pin is the single serial data I/O pin. In single-bit serial  
mode 3-wire interface operation, the SDIO_0 pin is the serial  
data input pin and the SDIO_2 pin is the output data pin.  
Regardless of the number of wires used in the interface, the  
SDIO_3 pin is configured as an input and operates as the  
SYNC_I/O pin in the single-bit serial mode and 2-bit serial  
mode. The SDIO_1 pin is unused in this mode (see Table 26).  
The following are the four programmable modes of serial I/O  
port operation:  
Single-bit serial 2-wire mode (default mode)  
Single-bit serial 3-wire mode  
2-bit serial mode  
4-bit serial mode (SYNC_I/O not available)  
2-Bit Serial Mode  
Table 26 displays the function of all six serial I/O interface pins,  
depending on the mode of serial I/O operation programmed.  
The SPI port operation in 2-bit serial mode is identical to the  
SPI port operation in single-bit serial mode, except that two bits  
of data are registered on each rising edge of SCLK. Therefore, it  
only takes four clock cycles to transfer eight bits of information.  
The SDIO_0 pin contains the even numbered data bits using  
the notation D[7:0], and the SDIO_1 pin contains the odd  
numbered data bits. This even and odd numbered pin/data  
alignment is valid in both MSB and LSB first formats (see  
Figure 44).  
Table 26. Serial I/O Port Pin Function vs. Serial I/O Mode  
Single-Bit  
Serial 2-Wire  
Mode  
Single-Bit  
Serial 3-Wire  
Mode  
2-Bit  
Serial  
Mode  
4-Bit  
Serial  
Mode  
Pin  
SCLK  
Serial clock  
Serial clock  
Serial clock Serial  
clock  
CS  
Chip select  
Chip select  
Chip select  
Chip  
select  
SDIO_0 Serial data I/O Serial data in  
Serial data  
I/O  
Serial  
data I/O  
4-Bit Serial Mode  
SDIO_1 Not used for  
SDIO1  
SDIO_2 Not used for  
SDIO1  
Not used for  
SDIO1  
Serial data  
out (SDO)  
Serial data  
I/O  
Not used  
for SDIO1  
Serial  
data I/O  
Serial  
data I/O  
Serial  
data I/O  
The SPI port in 4-bit serial mode is identical to the SPI port in  
single-bit serial mode, except that four bits of data are registered  
on each rising edge of SCLK. Therefore, it takes only two clock  
cycles to transfer eight bits of information. The SDIO_0 and  
SDIO_2 pins contain even numbered data bits using the notation  
D[7:0], and the SDIO_0 pin contains the LSB of the nibble. The  
SDIO_1 and SDIO_3 pins contain the odd numbered data bits,  
and the SDIO_1 pin contains the LSB of the nibble to be accessed.  
SDIO_3 SYNC_I/O  
SYNC_I/O  
SYNC_I/O  
1 In serial mode, these pins (SDIO_0/SDIO_1/SDIO_2/SDIO_3) can be used for  
RU/RD operation.  
The two bits in the channel select register, CSR[2:1], set the  
serial I/O mode of operation and are defined in Table 27.  
Note that when programming the device for 4-bit serial mode,  
it is important to keep the SDIO_3 pin at Logic 0 until the device is  
programmed out of the single-bit serial mode. Failure to do so  
can result in the serial I/O port controller being out of sequence.  
Table 27. Serial I/O Mode of Operation  
Serial I/O Mode Select  
(CSR[2:1])  
Mode of Operation  
Figure 43 through Figure 45 represent write timing diagrams  
for each of the serial I/O modes available. Both MSB and LSB  
first modes are shown. LSB first bits are shown in parentheses.  
The clock stall low/high feature shown is not required. It is used  
to show that data (SDIO) must have the proper setup time  
relative to the rising edge of SCLK.  
00  
01  
10  
11  
Single-bit serial mode (2-wire mode)  
Single-bit serial mode (3-wire mode)  
2-bit serial mode  
4-bit serial mode  
Single-Bit Serial (2-Wire and 3-Wire) Modes  
The single-bit serial mode interface allows read/write access to  
all registers that configure the AD9959. MSB first or LSB first  
transfer formats are supported. In addition, the single-bit serial  
mode interface port can be configured either as a single pin I/O,  
which allows a 2-wire interface, or as two unidirectional pins  
for input/output, which enable a 3-wire interface. Single-bit  
mode allows the use of the SYNC_I/O function.  
Figure 46 through Figure 49 represent read timing diagrams for  
each of the serial I/O modes available. Both MSB and LSB first  
modes are shown. LSB first bits are shown in parentheses. The  
clock stall low/high feature shown is not required. It is used to  
show that data (SDIO) must have the proper setup time relative  
to the rising edge of SCLK for the instruction byte and the read  
data that follows the falling edge of SCLK.  
Rev. B | Page 33 of 44  
 
 
 
 
 
AD9959  
INSTRUCTION CYCLE  
DATA TRANSFER CYCLE  
CS  
SCLK  
I7  
(I0)  
I6  
(I1)  
I5  
(I2)  
I4  
(I3)  
I3  
(I4)  
I2  
(I5)  
I1  
(I6)  
I0  
(I7)  
D7  
(D0)  
D6  
(D1)  
D5  
(D2)  
D4  
(D3)  
D3  
(D4)  
D2  
(D5)  
D1  
(D6)  
D0  
(D7)  
SDIO_0  
Figure 43. Single-Bit Serial Mode Write Timing—Clock Stall Low  
INSTRUCTION CYCLE  
DATA TRANSFER CYCLE  
CS  
SCLK  
I7  
I5  
I3  
I1  
D7  
D5  
D3  
D1  
SDIO_1  
SDIO_0  
(I1)  
(I3)  
(I5)  
(I7)  
(D1)  
(D3)  
(D5)  
(D7)  
I6  
(I0)  
I4  
(I2)  
I2  
(I4)  
I0  
(I6)  
D6  
(D0)  
D4  
(D2)  
D2  
(D4)  
D0  
(D6)  
Figure 44. 2-Bit Serial Mode Write Timing—Clock Stall Low  
INSTRUCTION CYCLE  
DATA TRANSFER CYCLE  
CS  
SCLK  
I7  
(I3)  
I3  
(I7)  
D7  
(D3)  
D3  
(D7)  
SDIO_3  
I6  
I2  
D6  
D2  
SDIO_2  
SDIO_1  
(I2)  
(I6)  
(D2)  
(D6)  
I5  
(I1)  
I1  
(I5)  
D5  
(D1)  
D1  
(D5)  
I4  
(I0)  
I0  
(I4)  
D4  
(D0)  
D0  
(D4)  
SDIO_0  
Figure 45. 4-Bit Serial Mode Write Timing—Clock Stall Low  
Rev. B | Page 34 of 44  
 
 
 
AD9959  
DATA TRANSFER CYCLE  
INSTRUCTION CYCLE  
CS  
SCLK  
I7  
(I0)  
I6  
(I1)  
I5  
(I2)  
I4  
(I3)  
I3  
(I4)  
I2  
(I5)  
I1  
(I6)  
I0  
(I7)  
D7  
(D0)  
D6  
(D1)  
D5  
(D2)  
D4  
(D3)  
D3  
(D4)  
D2  
(D5)  
D1  
(D6)  
D0  
(D7)  
SDIO_0  
Figure 46. Single-Bit Serial Mode (2-Wire) Read Timing—Clock Stall High  
DATA TRANSFER CYCLE  
INSTRUCTION CYCLE  
CS  
SCLK  
I7  
(I0)  
I6  
(I1)  
I5  
(I2)  
I4  
(I3)  
I3  
(I4)  
I2  
(I5)  
I1  
(I6)  
I0  
(I7)  
DON'T CARE  
SDIO_0  
SDO  
D7  
(D0)  
D6  
(D1)  
D5  
(D2)  
D4  
(D3)  
D3  
(D4)  
D2  
(D5)  
D1  
(D6)  
D0  
(D7)  
(SDIO_2 PIN)  
Figure 47. Single-Bit Serial Mode (3-Wire) Read Timing—Clock Stall Low  
INSTRUCTION CYCLE  
DATA TRANSFER CYCLE  
CS  
SCLK  
D7  
D5  
D3  
D1  
I7  
I5  
I3  
I1  
SDIO_1  
SDIO_0  
(D1)  
(D3)  
(D5)  
(D7)  
(I1)  
(I3)  
(I5)  
(I7)  
I6  
(I0)  
I4  
(I2)  
I2  
(I4)  
I0  
(I6)  
D6  
(D0)  
D4  
(D2)  
D2  
(D4)  
D0  
(D6)  
Figure 48. 2-Bit Serial Mode Read Timing—Clock Stall High  
INSTRUCTION CYCLE  
DATA TRANSFER CYCLE  
CS  
SCLK  
I7  
I3  
D7  
D3  
(I3)  
(I7)  
SDIO_3  
SDIO_2  
SDIO_1  
SDIO_0  
(D7)  
(D3)  
I6  
(I2)  
I2  
(I6)  
D6  
(D2)  
D2  
(I6)  
I5  
(I1)  
I1  
(I5)  
D5  
D1  
(D1) (D5)  
I4  
(I0)  
I0  
(I4)  
D4  
D0  
(D0) (D4)  
Figure 49. 4-Bit Serial Mode Read Timing—Clock Stall High  
Rev. B | Page 35 of 44  
 
 
AD9959  
REGISTER MAPS AND BIT DESCRIPTIONS  
REGISTER MAPS  
Table 28. Control Register Map  
Register  
Name  
(Serial  
Address)  
Bit  
Range  
Bit 7  
(MSB)  
Bit 0  
(LSB)  
Default  
Value  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Channel  
Select  
[7:0]  
Channel 3  
enable1  
Channel 2  
enable1  
Channel 1  
enable1  
Channel 0  
enable1  
Must  
be 0  
Serial I/O mode  
select[2:1]  
LSB first  
0xF0  
Register  
(CSR)  
(0x00)  
Function  
Register 1  
(FR1)  
[23:16]  
VCO gain  
control  
PLL divider ratio[22:18]  
Charge pump  
control[17:16]  
0x00  
(0x01)  
[15:8]  
[7:0]  
Open  
Profile pin configuration (PPC)[14:12]  
Ramp-up/  
ramp-down  
(RU/RD)[11:10]  
Modulation level[9:8]  
0x00  
0x00  
0x00  
Reference  
clock input  
power-down  
External power-  
down mode  
SYNC_CLK  
disable  
DAC reference  
power-down  
Open[3:2]  
Manual  
hardware  
sync  
Manual  
software  
sync  
Function  
Register 2  
(FR2)  
[15:8]  
All channels  
autoclear  
sweep  
All channels  
clear sweep  
accumulator  
All channels  
autoclear phase  
accumulator  
All channels  
clear phase  
accumulator  
Open[11:10]  
Open[9:8]  
(0x02)  
accumulator  
[7:0]  
Auto sync  
enable  
Multidevice sync Multidevice sync Multidevice sync  
master enable status mask  
Open[3:2]  
System clock  
offset[1:0]  
0x00  
1 Channel enable bits do not require an I/O update to be activated. These bits are active immediately after the byte containing the bits is written. All other bits need an  
I/O update to become active. The four channel enable bits shown in Table 28 are used to enable/disable any combination of the four channels. The default for all four  
channels is enabled.  
In the channel select register, if the user wants four different  
frequencies for all four DDS channels, use the following  
protocol:  
3. Enable the Channel 1 enable bit only, located in the  
channel select register, and disable the other three  
channels.  
1. Enable (Logic 1) the Channel 0 enable bit, which is located  
in the channel select register, and disable the other three  
channels (Logic 0).  
4. Write the desired frequency tuning word for Channel 1 in  
Step 3, then disable the Channel 1 enable bit.  
2. Write the desired frequency tuning word for Channel 0, as  
described in Step 1, and then disable the Channel 0 enable  
bit (Logic 0).  
Rev. B | Page 36 of 44  
 
 
 
 
AD9959  
Table 29. Channel Register Map  
Register  
Name  
(Serial  
Address)  
Bit  
Range  
Bit 7  
(MSB)  
Bit 0  
(LSB)  
Default  
Value  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Open[21:16]  
Bit 1  
Channel  
Function  
Register1  
(CFR)  
[23:16]  
[15:8]  
Amplitude freq. phase  
(AFP) select[23:22]  
0x00  
Linear  
sweep  
no-dwell  
Linear  
sweep  
enable  
Load SRR at  
I/O_UPDATE  
Open[12:11]  
Must be 0  
DAC full-scale current  
control[9:8]  
0x03  
0x02  
(0x03)  
[7:0]  
Digital  
power-  
down  
DAC  
power-  
down  
Matched  
pipe delays  
active  
Autoclear  
sweep  
accumulator  
Clear sweep  
accumulator  
Autoclear  
phase  
accumulator  
Clear phase  
Sine  
accumulator2 wave  
output  
enable  
Channel  
Frequency  
Tuning  
[31:24]  
[23:16]  
[15:8]  
[7:0]  
Frequency Tuning Word 0[31:24]  
Frequency Tuning Word 0[23:16]  
Frequency Tuning Word 0[15:8]  
Frequency Tuning Word 0[7:0]  
0x00  
N/A  
N/A  
N/A  
Word 01  
(CFTW0)  
(0x04)  
Channel  
Phase  
[15:8]  
[7:0]  
Open[15:14]  
Phase Offset Word 0[13:8]  
Phase Offset Word 0[7:0]  
0x00  
0x00  
Offset  
Word 01  
(CPOW0)  
(0x05)  
Amplitude  
Control  
Register  
(ACR)  
[23:16]  
[15:8]  
Amplitude ramp rate[23:16]  
N/A  
Increment/decrement  
step size[15:14]  
Open  
Amplitude  
multiplier  
enable  
Ramp-up/  
ramp-down  
enable  
Load ARR at  
I/O_UPDATE  
Amplitude scale  
factor[9:8]  
0x00  
(0x06)  
[7:0]  
[15:8]  
[7:0]  
Amplitude scale factor[7:0]  
0x00  
N/A  
N/A  
Linear  
Sweep  
Ramp  
Rate1  
Falling sweep ramp rate (FSRR)[15:8]  
Rising sweep ramp rate (RSRR)[7:0]  
(LSRR)  
(0x07)  
LSR Rising  
Delta  
[31:24]  
[23:16]  
[15:8]  
[7:0]  
Rising delta word[31:24]  
Rising delta word[23:16]  
Rising delta word[15:8]  
Rising delta word[7:0]  
N/A  
N/A  
N/A  
N/A  
Word1  
(RDW)  
(0x08)  
LSR Falling  
Delta  
[31:24]  
[23:16]  
[15:8]  
[7:0]  
Falling delta word[31:24]  
Falling delta word[23:16]  
Falling delta word[15:8]  
Falling delta word[7:0]  
N/A  
N/A  
N/A  
N/A  
Word1  
(FDW)  
(0x09)  
1 There are four sets of channel registers and profile registers, one per channel. This is not shown in the Table 29 or Table 30 because the addresses of all channel  
registers and profile registers are the same for each channel. Therefore, the channel enable bits (CSR[7:4]) determine if the channel registers and/or profile registers of  
each channel are written to or not.  
2 The clear phase accumulator bit is set to Logic 1 after a master reset. It self-clears or is set to Logic 0 when an I/O update is asserted.  
Rev. B | Page 37 of 44  
 
 
AD9959  
Table 30. Profile Register Map1  
Bit  
Range  
Bit 7  
(MSB)  
Bit 0  
(LSB)  
Default  
Value  
Register Name (Address)  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Channel Word 1 (CW1) (0x0A)  
Channel Word 2 (CW2) (0x0B)  
Channel Word 3 (CW3) (0x0C)  
Channel Word 3 (CW4) (0x0D)  
Channel Word 5 (CW5) (0x0E)  
Channel Word 6 (CW6) (0x0F)  
Channel Word 7 (CW7) (0x10)  
Channel Word 8 (CW8) (0x11)  
Channel Word 9 (CW9) (0x12)  
Channel Word 10 (CW10) (0x13)  
Channel Word 11 (CW11) (0x14)  
Channel Word 12 (CW12) (0x15)  
Channel Word 13 (CW13) (0x16)  
Channel Word 14 (CW14) (0x17)  
Channel Word 15 (CW15) (0x18)  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
[31:0]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
Frequency tuning word[31:0] or phase word[31:18] or amplitude word[31:22]  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
1 Each channel word register has a capacity of 32 bits. If phase or amplitude is stored in the channel word registers, it must be first MSB aligned per the bit range.  
Only the MSB byte is shown for each channel word register.  
Rev. B | Page 38 of 44  
 
 
AD9959  
DESCRIPTIONS FOR CONTROL REGISTERS  
Channel Select Register (CSR)—Address 0x00  
One byte is assigned to this register.  
The CSR determines if channels are enabled or disabled by the status of the four channel enable bits. All four channels are enabled by  
their default state. The CSR also determines which serial mode of operation is selected. In addition, the CSR offers a choice of MSB first  
or LSB first format.  
Table 31. Bit Descriptions for CSR  
Bit  
Mnemonic  
Description  
7:4  
Channel [3:0] enable  
Bits are active immediately after being written. They do not require an I/O update to take effect.  
There are four sets of channel registers and profile (channel word) registers, one per channel. This  
is not shown in the channel register map or the profile register map. The addresses of all channel  
registers and profile registers are the same for each channel. Therefore, the channel enable bits  
distinguish the channel registers and profile registers values of each channel. For example,  
1001 = only Channel 3 and Channel 0 receive commands from the channel registers and profile  
registers.  
0010 = only Channel 1 receives commands from the channel registers and profile registers.  
Must be set to 0.  
3
Must be 0  
2:1  
Serial I/O mode select  
00 = single-bit serial (2-wire mode).  
01 = single-bit serial (3-wire mode).  
10 = 2-bit serial mode.  
11 = 4-bit serial mode.  
See the Serial I/O Modes of Operation section for more details.  
0 = the serial interface accepts serial data in MSB first format (default).  
1 = the serial interface accepts serial data in LSB first format.  
0
LSB first  
Function Register 1 (FR1)—Address 0x01  
Three bytes are assigned to this register. FR1 is used to control the mode of operation of the chip.  
Table 32. Bit Descriptions for FR1  
Bit  
Mnemonic  
Description  
23  
VCO gain control  
0 = the low range (system clock below 160 MHz) (default).  
1 = the high range (system clock above 255 MHz).  
22:18 PLL divider ratio  
If the value is 4 or 20 (decimal) or between 4 and 20, the PLL is enabled and the value sets the  
multiplication factor. If the value is outside of 4 and 20 (decimal), the PLL is disabled.  
17:16 Charge pump control  
00 (default) = the charge pump current is 75 μA.  
01 = charge pump current is 100 μA.  
10 = charge pump current is 125 μA.  
11 = charge pump current is 150 μA.  
15  
Open  
14:12 Profile pin configuration (PPC)  
The profile pin configuration bits control the configuration of the data and SDIO_x pins for the  
different modulation modes. See the Modulation Mode section in this document for details.  
11:10 Ramp-up/ramp-down (RU/RD) The RU/RD bits control the amplitude ramp-up/ramp-down time of a channel. See the Output  
Amplitude Control Mode section for more details.  
9:8  
Modulation level  
The modulation (FSK, PSK, and ASK) level bits control the level (2/4/8/16) of modulation to be  
performed for a channel. See the Modulation Mode section for more details.  
7
Reference clock input  
power-down  
0 = the clock input circuitry is enabled for operation (default).  
1 = the clock input circuitry is disabled and is in a low power dissipation state.  
6
External power-down mode  
0 = the external power-down mode is in fast recovery power-down mode (default). In this mode,  
when the PWR_DWN_CTL input pin is high, the digital logic and the DAC digital logic are  
powered down. The DAC bias circuitry, PLL, oscillator, and clock input circuitry are not powered  
down.  
1 = the external power-down mode is in full power-down mode. In this mode, when the  
PWR_DWN_CTL input pin is high, all functions are powered down. This includes the DAC and PLL,  
which take a significant amount of time to power up.  
Rev. B | Page 39 of 44  
 
 
AD9959  
Bit  
Mnemonic  
Description  
5
SYNC_CLK disable  
0 = the SYNC_CLK pin is active (default).  
1 = the SYNC_CLK pin assumes a static Logic 0 state (disabled). In this state, the pin drive logic is  
shut down. However, the synchronization circuitry remains active internally to maintain normal  
device operation.  
4
DAC reference power-down  
0 = DAC reference is enabled (default).  
1 = DAC reference is powered down.  
3:2  
1
Open  
See the Synchronizing Multiple AD9959 Devices section for details.  
0 = the manual hardware synchronization feature of multiple devices is inactive (default).  
1 = the manual hardware synchronization feature of multiple devices is active.  
0 = the manual software synchronization feature of multiple devices is inactive (default).  
Manual hardware sync  
0
Manual software sync  
1 = the manual software synchronization feature of multiple devices is active. See the  
Synchronizing Multiple AD9959 Devices section for details.  
Function Register 2 (FR2)—Address 0x02  
Two bytes are assigned to this register. The FR2 is used to control the various functions, features, and modes of the AD9959.  
Table 33. Bit Descriptions for FR2  
Bit  
Mnemonic  
Description  
15  
All channels autoclear sweep  
accumulator  
0 = a new delta word is applied to the input, as in normal operation, but not loaded into the  
accumulator (default).  
1 = this bit automatically and synchronously clears (loads 0s into) the sweep accumulator for one  
cycle upon reception of the I/O_UPDATE sequence indicator on all four channels.  
14  
13  
All channels clear  
sweep accumulator  
All channels autoclear phase  
accumulator  
0 = the sweep accumulator functions as normal (default).  
1 = the sweep accumulator memory elements for all four channels are asynchronously cleared.  
0 = a new frequency tuning word is applied to the inputs of the phase accumulator, but not  
loaded into the accumulator (default).  
1 = this bit automatically and synchronously clears (loads 0s into) the phase accumulator for one  
cycle upon receipt of the I/O update sequence indicator on all four channels.  
12  
All channels clear phase  
accumulator  
0 = the phase accumulator functions as normal (default).  
1 = the phase accumulator memory elements for all four channels are asynchronously cleared.  
11:8  
7
6
5
4
Open  
Auto sync enable  
Multidevice sync master enable  
Multidevice sync status  
Multidevice sync mask  
Open  
See the Synchronizing Multiple AD9959 Devices section for more details.  
See the Synchronizing Multiple AD9959 Devices section for more details.  
See the Synchronizing Multiple AD9959 Devices section for more details.  
See the Synchronizing Multiple AD9959 Devices section for more details.  
3: 2  
1:0  
System clock offset  
See the Synchronizing Multiple AD9959 Devices section for more details.  
Rev. B | Page 40 of 44  
AD9959  
DESCRIPTIONS FOR CHANNEL REGISTERS  
Channel Function Register (CFR)—Address 0x03  
Three bytes are assigned to this register.  
Table 34. Bit Descriptions for CFR  
Bit  
Mnemonic  
Description  
23:22 Amplitude frequency  
phase (AFP) select  
Controls what type of modulation is to be performed for that channel. See the Modulation Mode section  
for details.  
21:16 Open  
15  
14  
13  
Linear sweep no-dwell  
0 = the linear sweep no-dwell function is inactive (default).  
1 = the linear sweep no-dwell function is active. If CFR[15] is active, the linear sweep no-dwell function is  
activated. See the Linear Sweep Mode section for details. If CFR[14] is clear, this bit is don’t care.  
0 = the linear sweep capability is inactive (default).  
1 = the linear sweep capability is enabled. When enabled, the delta frequency tuning word is applied to  
the frequency accumulator at the programmed ramp rate.  
Linear sweep enable  
Load SRR at  
I/O_UPDATE  
0 = the linear sweep ramp rate timer is loaded only upon timeout (timer = 1) and is not loaded because  
of an I/O_UPDATE input signal (default).  
1 = the linear sweep ramp rate timer is loaded upon timeout (timer = 1) or at the time of an I/O_UPDATE  
input signal.  
12:11 Open  
10  
Must be 0  
Must be set to 0.  
9:8  
DAC full-scale current  
control  
11 = the DAC is at the largest LSB value (default).  
See Table 5 for other settings.  
7
6
5
Digital power-down  
0 = the digital core is enabled for operation (default).  
1 = the digital core is disabled and is in its lowest power dissipation state.  
0 = the DAC is enabled for operation (default).  
1 = the DAC is disabled and is in its lowest power dissipation state.  
0 = matched pipe delay mode is inactive (default).  
DAC power-down  
Matched pipe delays  
active  
1 = matched pipe delay mode is active. See the Single-Tone Mode—Matched Pipeline Delay section for  
details.  
4
Autoclear sweep  
accumulator  
0 = the current state of the sweep accumulator is not impacted by receipt of an I/O_UPDATE signal  
(default).  
1 = the sweep accumulator is automatically and synchronously cleared for one cycle upon receipt  
of an I/O_UPDATE signal.  
3
2
Clear sweep  
accumulator  
Autoclear phase  
accumulator  
0 = the sweep accumulator functions as normal (default).  
1 = the sweep accumulator memory elements are asynchronously cleared.  
0 = the current state of the phase accumulator is not impacted by receipt of an I/O_UPDATE signal  
(default).  
1 = the phase accumulator is automatically and synchronously cleared for one cycle upon receipt  
of an I/O_UPDATE signal.  
1
0
Clear phase  
accumulator  
Sine wave output  
enable  
0 = the phase accumulator functions as normal (default).  
1 = the phase accumulator memory elements are asynchronously cleared.  
0 = the angle-to-amplitude conversion logic employs a cosine function (default).  
1 = the angle-to-amplitude conversion logic employs a sine function.  
Rev. B | Page 41 of 44  
 
AD9959  
Channel Frequency Tuning Word 0 (CFTW0)—Address 0x04  
Four bytes are assigned to this register.  
Table 35. Description for CFTW0  
Bit  
Mnemonic  
Description  
31:0  
Frequency Tuning Word 0 Frequency Tuning Word 0 for each channel.  
Channel Phase Offset Word 0 (CPOW0)—Address 0x05  
Two bytes are assigned to this register.  
Table 36. Description for CPOW0  
Bit  
Mnemonic  
Description  
15:14  
13:0  
Open  
Phase Offset Word 0  
Phase Offset Word 0 for each channel  
Amplitude Control Register (ACR)—Address0x06  
Three bytes are assigned to this register.  
Table 37. Description for ACR  
Bit  
Mnemonic  
Description  
23:16  
15:14  
Amplitude ramp rate  
Increment/decrement  
step size  
Amplitude ramp rate value.  
Amplitude increment/decrement step size.  
13  
12  
Open  
Amplitude multiplier  
enable  
0 = amplitude multiplier is disabled. The clocks to this scaling function (auto RU/RD) are stopped  
for power saving, and the data from the DDS core is routed around the multipliers (default).  
1 = amplitude multiplier is enabled.  
11  
Ramp-up/ramp-down  
enable  
This bit is valid only when ACR[12] is active high.  
0 = when ACR[12] is active, Logic 0 on ACR[11] enables the manual RU/RD operation. See the  
Output Amplitude Control Mode section for details (default).  
1 = if ACR[12] is active, a Logic 1 on ACR[11] enables the auto RU/RD operation. See the Output  
Amplitude Control Mode section for details.  
10  
Load ARR at  
I/O_UPDATE  
0 = the amplitude ramp rate timer is loaded only upon timeout (timer = 1) and is not loaded due  
to an I/O_UPDATE input signal (default).  
1 = the amplitude ramp rate timer is loaded upon timeout (timer = 1) or at the time of an  
I/O_UPDATE input signal.  
9:0  
Amplitude scale factor  
Amplitude scale factor for each channel.  
Rev. B | Page 42 of 44  
AD9959  
Linear Sweep Ramp Rate (LSRR)—Address 0x07  
Two bytes are assigned to this register.  
Table 38. Description for LSRR  
Bit  
Mnemonic  
Description  
15:8  
7:0  
Falling sweep ramp rate (FSRR)  
Rising sweep ramp rate (RSRR)  
Linear falling sweep ramp rate.  
Linear rising sweep ramp rate.  
LSR Rising Delta Word (RDW)—Address 0x08  
Four bytes are assigned to this register.  
Table 39. Description for RDW  
Bit  
Mnemonic  
Description  
31:0  
Rising delta word  
32-bit rising delta-tuning word.  
LSR Falling Delta Word (FDW)—Address 0x09  
Four bytes are assigned to this register.  
Table 40. Description for FDW  
Bit  
Mnemonic  
Description  
31:0  
Falling delta word  
32-bit falling delta-tuning word.  
Rev. B | Page 43 of 44  
AD9959  
OUTLINE DIMENSIONS  
0.30  
0.23  
0.18  
8.00  
BSC SQ  
0.60 MAX  
0.60 MAX  
PIN 1  
INDICATOR  
43  
42  
56  
1
PIN 1  
INDICATOR  
6.25  
6.10 SQ  
5.95  
TOP  
VIEW  
EXPOSED  
7.75  
BSC SQ  
PAD  
(BOTTOM VIEW)  
0.50  
0.40  
0.30  
29  
28  
14  
15  
0.25 MIN  
6.50  
REF  
0.80 MAX  
0.65 TYP  
1.00  
0.85  
0.80  
12° MAX  
0.05 MAX  
0.02 NOM  
THE EXPOSED EPAD ON BOTTOM SIDE  
OF PACKAGE IS AN ELECTRICAL  
CONNECTION AND MUST BE  
COPLANARITY  
0.08  
SEATING  
PLANE  
0.50 BSC  
SOLDERED TO GROUND.  
0.20 REF  
COMPLIANT TO JEDEC STANDARDS MO-220-VLLD-2  
Figure 50. 56-Lead Lead Frame Chip Scale Package [LFCSP_VQ]  
8 mm × 8 mm Body, Very Thin Quad  
(CP-56-1)  
Dimensions shown in millimeters  
ORDERING GUIDE  
Model  
AD9959BCPZ1  
AD9959BCPZ-REEL71  
AD9959/PCBZ1  
Temperature Range  
Package Description  
Package Option  
CP-56-1  
CP-56-1  
–40°C to +85°C  
–40°C to +85°C  
56-Lead Lead Frame Chip Scale Package [LFCSP_VQ]  
56-Lead Lead Frame Chip Scale Package [LFCSP_VQ]  
Evaluation Board  
1 Z = RoHS Compliant Part.  
©2005–2008 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D05246-0-7/08(B)  
Rev. B | Page 44 of 44  
 
 

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