AD9739BBCZRL [ADI]

14-Bit, 2.5 GSPS, RF Digital-to-Analog Converter; 14位, 2.5 GSPS , RF数位类比转换器
AD9739BBCZRL
型号: AD9739BBCZRL
厂家: ADI    ADI
描述:

14-Bit, 2.5 GSPS, RF Digital-to-Analog Converter
14位, 2.5 GSPS , RF数位类比转换器

转换器
文件: 总48页 (文件大小:856K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
14-Bit, 2.5 GSPS,  
RF Digital-to-Analog Converter  
AD9739  
Data Sheet  
FEATURES  
FUNCTIONAL BLOCK DIAGRAM  
Direct RF synthesis at 2.5 GSPS update rate  
DC to 1.25 GHz in baseband mode  
RESET  
IRQ  
1.25 GHz to 3.0 GHz in mix mode  
Industry leading single/multicarrier IF or RF synthesis  
AD9739  
1.2V  
SDIO  
SDO  
CS  
SPI  
DAC BIAS  
fOUT = 350 MHz, ACLR =80 dBc  
fOUT = 950 MHz, ACLR = 78 dBc  
fOUT = 2100 MHz, ACLR = 69 dBc  
VREF  
I120  
SCLK  
Dual-port LVDS data interface  
Up to 1.25 GSPS operation  
Source synchronous DDR clocking  
Pin-compatible with the AD9739A  
Multichip synchronization capability  
Programmable output current: 8.7 mA to 31.7 mA  
Low power: 1.16 W at 2.5 GSPS  
IOUTP  
IOUTN  
TxDAC  
CORE  
DCI  
APPLICATIONS  
CLK DISTRIBUTION  
(DIV-BY-4)  
Broadband communications systems  
Military jammers  
Instrumentation, automatic test equipment  
Radar, avionics  
DCO  
SYNC_OUT  
SYNC_IN  
SYNC-  
CONTROLLER  
DACCLK  
Figure 1.  
GENERAL DESCRIPTION  
The AD9739 is a 14-bit, 2.5 GSPS high performance RF digital-  
to-analog converter (DAC) capable of synthesizing wideband  
signals from dc up to 3.0 GHz. Its DAC core features a quad-  
switch architecture that provides exceptionally low distortion  
performance with an industry-leading direct RF synthesis  
capability. This feature enables multicarrier generation up to  
the Nyquist frequency in baseband mode as well as second and  
third Nyquist zones in mix mode. The output current can be  
programmed over the 8.66 mA to 31.66 mA range.  
PRODUCT HIGHLIGHTS  
1. Ability to synthesize high quality wideband signals with  
bandwidths of up to 1.25 GHz in the first or second  
Nyquist zone.  
2. A proprietary quad-switch DAC architecture provides  
exceptional ac linearity performance while enabling mix  
mode operation.  
3. A dual-port, double data rate, LVDS interface supports the  
maximum conversion rate of 2500 MSPS.  
4. On-chip controllers manage external and internal clock  
domain skews.  
5. A multichip synchronization capability.  
6. Programmable differential current output with a 8.66 mA  
to 31.66 mA range.  
The inclusion of on-chip controllers simplifies system integration.  
A dual-port, source synchronous, LVDS interface simplifies the  
digital interface with existing FGPA/ASIC technology. On-chip  
controllers are used to manage external and internal clock domain  
variations over temperature to ensure reliable data transfer from  
the host to the DAC core. Multichip synchronization is possible  
with an on-chip synchronization controller. A serial peripheral  
interface (SPI) is used for device configuration as well as readback  
of status registers.  
The AD9739 is manufactured on a 0.18 μm CMOS process and  
operates from 1.8 V and 3.3 V supplies. It is supplied in a 160-ball  
chip scale ball grid array for reduced package parasitics.  
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 ©2009–2012 Analog Devices, Inc. All rights reserved.  
 
AD9739  
Data Sheet  
TABLE OF CONTENTS  
Features .............................................................................................. 1  
DCI Phase Alignment Status .................................................... 23  
SYNC_IN Phase Alignment Status.......................................... 23  
Data Receiver Controller Configuration................................. 23  
Data Receiver Controller_Data Sample Delay Value ............ 24  
Applications....................................................................................... 1  
General Description......................................................................... 1  
Functional Block Diagram .............................................................. 1  
Product Highlights ........................................................................... 1  
Revision History ............................................................................... 2  
Specifications..................................................................................... 4  
DC Specifications ......................................................................... 4  
LVDS Digital Specifications........................................................ 5  
Serial Port Specifications............................................................. 6  
AC Specifications.......................................................................... 7  
Absolute Maximum Ratings............................................................ 8  
Thermal Resistance ...................................................................... 8  
ESD Caution.................................................................................. 8  
Pin Configurations and Function Descriptions ........................... 9  
Typical Performance Characteristics ........................................... 12  
AC (Normal Mode).................................................................... 12  
AC (Mix Mode) .......................................................................... 15  
Terminology .................................................................................... 17  
Serial Port Interface (SPI) Register............................................... 18  
SPI Register Map Description................................................... 18  
SPI Operation.............................................................................. 18  
SPI Register Map............................................................................. 20  
SPI Port Configuration and Software Reset............................ 22  
Power-Down LVDS Interface and TxDAC®............................ 22  
Controller Clock Disable........................................................... 22  
Interrupt Request (IRQ) Enable/Status ................................... 22  
TxDAC Full-Scale Current Setting (IOUTFS) and Sleep ........... 23  
TxDAC Quad-Switch Mode of Operation.............................. 23  
Data and Sync Receiver Controller_DCI Delay  
Value/Window and Phase Rotation......................................... 24  
Data Receiver Controller_Delay Line Status and Sync  
Controller SYNC_OUT Status ................................................. 24  
Sync and Data Receiver Controller Lock/Tracking Status.... 25  
CLK Input Common Mode ...................................................... 25  
Mu Controller Configuration and Status................................ 25  
Part ID ......................................................................................... 26  
Theory of Operation ...................................................................... 27  
LVDS Data Port Interface.......................................................... 28  
Mu Controller............................................................................. 32  
Interrupt Requests...................................................................... 34  
Multiple Device Synchronization............................................. 35  
Analog Interface Considerations.................................................. 38  
Analog Modes of Operation ..................................................... 38  
Clock Input Considerations...................................................... 39  
Voltage Reference ....................................................................... 40  
Analog Outputs .......................................................................... 40  
Nonideal Spectral Artifacts....................................................... 43  
Lab Evaluation of the AD9739 ................................................. 44  
Power Dissipation and Supply Domains................................. 44  
Recommended Start-Up Sequence .......................................... 45  
Outline Dimensions....................................................................... 48  
Ordering Guide .......................................................................... 48  
REVISION HISTORY  
1/12—Rev. A to Rev. B  
Deleted Static Linearity Section and Figure 7 to Figure 17;  
Renumbered Sequentially ............................................................. 11  
Changed Dynamic Performance Normal Mode, 20 mA Full  
Scale (Unless Otherwise Noted) Section to AC (Normal Mode)  
Section.............................................................................................. 12  
Changes to AC (Normal Mode) Section ..................................... 12  
Changed Dynamic Performance Mix Mode, 20 mA Full Scale  
Section to AC (Mix Mode) Section.............................................. 15  
Changes to AC (Mix Mode) Section............................................ 15  
Added Serial Port Interface (SPI) Register Section, SPI Register  
Map Description Section, Reset Section, Table 8, and SPI  
Operation Section and Figure 34 ................................................. 18  
Changes to Features Section, Applications Section, General  
Description Section, Figure 1, Product Highlights Section........ 1  
Changes to DC Specifications Section........................................... 4  
Changed Digital Specifications Section to LVDS Digital  
Specifications Section....................................................................... 5  
Changes to LVDS Digital Specifications Section ......................... 5  
Added Serial Port Specifications Section and Table 3;  
Renumbered Sequentially................................................................ 6  
Changes to AC Specifications Section ........................................... 7  
Changes to Table 5............................................................................ 8  
Changes to Table 7.......................................................................... 10  
Rev. B | Page 2 of 48  
 
Data Sheet  
AD9739  
Deleted DOCSIS Performance Section and  
Changes to Analog Modes of Operation Section .......................38  
Deleted Clocking the AD9739 Section, Figure 85, and Figure 86..39  
Added Clock Input Considerations Section, Figure 58 to  
Figure 46 to Figure 72.....................................................................19  
Added Figure 35 through Figure 38; Renumbered Sequentially....19  
Changes to SPI Register Map Section and Table 9......................20  
Added SPI Port Configuration and Software Reset Section,  
Power-Down LVDS Interface and TxDAC® Section, Controller  
Clock Disable Section, Interrupt Request (IRQ) Enable/Status  
Section, and Table 10 to Table 13..................................................22  
Added TxDAC Full-Scale Current Setting (IOUTFS) and Sleep  
Section, TxDAC Quad-Switch Mode of Operation Section, DCI  
Phase Alignment Status Section, SYNC_IN Phase Alignment  
Status Section, Data Receiver Controller Configuration Section,  
and Table 14 to Table 18 .................................................................23  
Added Data Receiver Controller_Data Sample Delay Value  
Section, Data and Sync Receiver Controller_DCI Delay  
Figure 60...........................................................................................39  
Deleted Clock Phase Noise Affects on AC Performance Section,  
Table 32 to Table 34, Applying Data to the AD9739 Section, and  
Figure 87...........................................................................................40  
Moved Figure 61..............................................................................40  
Changes to Voltage References Section and Analog Outputs  
Section ..............................................................................................40  
Added Equivalent DAC Output and Transfer Function and  
Figure 63...........................................................................................40  
Deleted Mu Control Operation Section, Search Mode Section,  
and Figure 89 ...................................................................................41  
Moved Figure 64..............................................................................41  
Added Peak DAC Output Power Capability Section and Figure 65. 41  
Deleted Figure 90, Figure 91, Track Mode Section, Mu Delay  
and Phase Readback Section, Operating the Mu Controller  
Manually Section, and Calculating Mu Delay Line Step Size  
Section ..............................................................................................42  
Added Output Stage Configuration Section and Figure 66 to  
Figure 70...........................................................................................42  
Added Nonideal Spectral Artifacts Section, Figure 71, and  
Table 30.............................................................................................43  
Deleted Operation in Master Mode, Figure 93, and  
Figure 94...........................................................................................44  
Added Lab Evaluation of the AD9739 Section, Power Dissipation  
and Supply Domains Section, and Figure 72 to Figure 74.........44  
Deleted Figure 95, Operation in Slave Mode Section, and Data  
Receiver Operation in Auto Mode Section..................................45  
Changes to Recommended Start-Up Sequence Section ............45  
Added Figure 75..............................................................................45  
Deleted Figure 97, Data Receiver Operation in Manual Mode  
Section, Calculating the DCI Delay Line Step Size Section, and  
Maximum Allowable Data Timing Skew/Jitter Section.............46  
Added Table 31................................................................................46  
Deleted Optimizing the Clock Common-Mode Voltage Section,  
Figure 99, Analog Control Registers Section, Mirror Roll-Off  
Frequency Control Section, and Figure 101................................47  
Added Table 32................................................................................47  
Deleted Figure 103, Figure 104, and Figure 106 .........................48  
Updated Outline Dimensions........................................................48  
Deleted Figure 107 to Figure 109..................................................49  
Deleted Table 35 to Table 44..........................................................50  
Value/Window and Phase Rotation Section, Data Receiver  
Controller_Delay Line Status and Sync Controller SYNC_OUT  
Status Section, and Table 19 to Table 21.......................................24  
Deleted Serial Peripheral Interface Section, General Operation  
of the Serial Interface Section, Instruction Mode (8-Bit Instruction)  
Section, and Serial Interface Port Pin Description Section.......25  
Added Sync and Data Receiver Controller Lock/Tracking Status  
Section, CLK Input Common Mode Section, Mu Controller  
Configuration and Status Section, and Table 22 to Table 24.....25  
Deleted MSB/LSB Transfers Section, Serial Port Configuration  
Section, and Figure 74 to Figure 79 ..............................................26  
Added Part ID Section and Table 25 ............................................26  
Changes to Theory of Operation Section ....................................27  
Added Figure 39 ..............................................................................27  
Deleted SPI Registers Section and Table 8 to Table 31...............28  
Moved and Changes to LVDS Data Port Interface Section .......28  
Added Figure 40 and Figure 41 .....................................................28  
Changes to Figure 42 ......................................................................29  
Moved and Changes to Figure 43..................................................29  
Added Data Receiver Controller Initialization Description  
Section, Table 26, and Data Receiver Operation at Lower Clock  
Rates Section....................................................................................30  
Added LVDS Driver and Receiver Input Section, Figure 44 to  
Figure 47, and Table 27...................................................................31  
Changed and Moved Mu Delay Controller Section to Mu  
Controller Section...........................................................................32  
Changes to Mu Controller Section, Figure 48, and Figure 49...32  
Added Figure 50 and Table 28.......................................................32  
Added Mu Controller Initialization Description Section..........33  
Changes to Interrupt Requests Section ........................................34  
Added Table 29 ................................................................................34  
Changed Synchronization Controller Section to Multiple  
Device Synchronization Section....................................................35  
Added Figure 52 ..............................................................................35  
Changes to Figure 53 ......................................................................36  
Added Sync Controller Initialization Description Section........36  
Added Synchronization Limitations Section...............................37  
Changed Applications Information to Analog Interface  
7/11—Rev 0 to Rev A  
Changes to Table 2, DAC CLOCK INPUT (DACCLK_P,  
DACCLK_N), Added DAC Clock Rate .........................................4  
Changes to Table 3, Added Dynamic Performance Parameters.......5  
Change to Ordering Guide ............................................................53  
2/09—Revision 0: Initial Release  
Considerations Section...................................................................38  
Rev. B | Page 3 of 48  
AD9739  
Data Sheet  
SPECIFICATIONS  
DC SPECIFICATIONS  
VDDA = VDD33 = 3.3 V, VDDC = VDD = 1.8 V, IOUTFS = 20 mA.  
Table 1.  
Parameter  
Min  
Typ  
Max  
Unit  
RESOLUTION  
14  
Bits  
ACCURACY  
Integral Nonlinearity (INL)  
Differential Nonlinearity (DNL)  
±1.3  
±±.8  
LSB  
LSB  
ANALOG OUTPUTS  
Gain Error (with Internal Reference)  
5.5  
%
Full-Scale Output Current  
Output Compliance Range  
8.66  
−1.±  
2±.2  
31.66  
+1.±  
mA  
V
Common-Mode Output Resistance  
Differential Output Resistance  
Output Capacitance  
1±  
7±  
1
MΩ  
Ω
pF  
DAC CLOCK INPUT (DACCLK_P, DACCLK_N)  
Differential Peak-to-Peak Voltage  
Common-Mode Voltage  
DAC Clock Rate  
1.2  
±.8  
1.6  
9±±  
2.±  
2.5  
V
mV  
GHz  
TEMPERATURE DRIFT  
Gain  
Reference Voltage  
6±  
2±  
ppm/°C  
ppm/°C  
REFERENCE  
Internal Reference Voltage  
Output Resistance  
1.15  
1.2  
5
1.25  
V
kΩ  
ANALOG SUPPLY VOLTAGES  
VDDA  
VDDC  
3.1  
1.7±  
3.3  
1.8  
3.5  
1.9±  
V
V
DIGITAL SUPPLY VOLTAGES  
VDD33  
VDD  
3.1±  
1.7±  
3.3  
1.8  
3.5  
1.9±  
V
V
SUPPLY CURRENTS AND POWER DISSIPATION, 2.± GSPS  
IVDDA  
IVDDC  
IVDD33  
IVDD  
Power Dissipation  
Sleep Mode, IVDDA  
37  
159  
34  
233  
±.94±  
2.5  
38  
166  
37  
238  
±.975  
2.75  
mA  
mA  
mA  
mA  
W
mA  
Power-Down Mode (Register ±x±1 = ±x33 and Register ±x±2 = ±x8±)  
IVDDA  
IVDDC  
IVDD33  
IVDD  
±.±2  
3.8  
±.5  
mA  
mA  
mA  
mA  
±.1  
SUPPLY CURRENTS AND POWER DISSIPATION, 2.5 GSPS  
IVDDA  
IVDDC  
IVDD33  
IVDD  
37  
223  
34  
29±  
1.16  
mA  
mA  
mA  
mA  
W
Power Dissipation  
Rev. B | Page 4 of 48  
 
Data Sheet  
AD9739  
LVDS DIGITAL SPECIFICATIONS  
VDDA = VDD33 = 3.3 V, VDDC = VDD = 1.8 V, IOUTFS = 20 mA. LVDS drivers and receivers are compliant to the IEEE Standard 1596.3-  
1996 reduced range link, unless otherwise noted.  
Table 2.  
Parameter  
Min  
Typ  
Max  
Unit  
LVDS DATA INPUTS (DB±[13:±], DB1[13:±])1  
Input Common-Mode Voltage Range, VCOM  
Logic High Differential Input Threshold, VIH_DTH  
Logic Low Differential Input Threshold, VIL_DTH  
Receiver Differential Input Impedance, RIN  
Input Capacitance  
825  
175  
−175  
8±  
1575  
mV  
mV  
mV  
Ω
4±±  
−4±±  
12±  
1.2  
pF  
LVDS Input Rate  
125±  
MSPS  
ps  
LVDS Minimum Data Valid Period, tVALID (See Figure 41)  
LVDS CLOCK INPUT (DCI and SYNC_IN)2  
Input Common-Mode Voltage Range, VCOM  
Logic High Differential Input Threshold, VIH_DTH  
Logic Low Differential Input Threshold, VIL_DTH  
Receiver Differential Input Impedance, RIN  
Input Capacitance  
344  
825  
175  
−175  
8±  
1575  
mV  
mV  
mV  
Ω
4±±  
−4±±  
12±  
1.2  
pF  
Maximum Clock Rate  
625  
MHz  
LVDS CLOCK OUTPUT (DCO and SYNC_OUT)3  
Output Voltage High (x_P or x_N)  
Output Voltage Low (x_P or x_N)  
Output Differential Voltage, |VOD|  
Output Offset Voltage, VOS  
1375  
mV  
mV  
mV  
mV  
Ω
1±25  
15±  
115±  
8±  
2±±  
1±±  
25±  
125±  
12±  
1±  
Output Impedance, Single-Ended, RO  
RO Single-Ended Mismatch  
%
Maximum Clock Rate  
625  
MHz  
1 DB±[x]P, DB±[x]N, DB1[x]P, and DB1[x]N pins.  
2 DCI_P and DCI_N pins, as well as SYNC_IN_P and SYNC_IN_N pins.  
3 DCO_P and DCO_N pins, as well as SYNC_OUT_P/SYNC_OUT_N pins with 1±± Ω differential termination.  
Rev. B | Page 5 of 48  
 
AD9739  
Data Sheet  
SERIAL PORT SPECIFICATIONS  
VDDA = VDD33 = 3.3 V, VDDC = VDD = 1.8 V.  
Table 3.  
Parameter  
Min  
Typ  
Max  
Unit  
WRITE OPERATION (See Figure 36)  
SCLK Clock Rate, fSCLK (or /tSCLK  
SCLK Clock High, tHI  
SCLK Clock Low, tLOW  
SDIO to SCLK Setup Time, tDS  
SCLK to SDIO Hold Time, tDH  
CS to SCLK Setup Time, tS  
SCLK to CS Hold Time, tH  
)
2±  
MHz  
ns  
ns  
ns  
ns  
18  
18  
2
1
3
ns  
2
ns  
READ OPERATION (See Figure 37 and Figure 38)  
SCLK Clock Rate, fSCLK (or /tSCLK  
SCLK Clock High, tHI  
SCLK Clock Low, tLOW  
SDIO to SCLK Setup Time, tDS  
SCLK to SDIO Hold Time, tDH  
CS to SCLK Setup Time, tS  
)
2±  
15  
MHz  
ns  
ns  
ns  
ns  
18  
18  
2
1
3
ns  
SCLK to SDIO (or SDO) Data Valid Time, tDV  
ns  
CS to SDIO (or SDO) Output Valid to High-Z, tEZ  
2
ns  
INPUTS (SDIO, SCLK, CS)  
Voltage in High, VIH  
Voltage in Low, VIL  
Current in High, IIH  
Current in Low, IIL  
2.±  
3.3  
±
V
V
μA  
μA  
±.8  
+1±  
+1±  
−1±  
−1±  
OUTPUT (SDIO)  
Voltage Out High, VOH  
Voltage Out Low, VOL  
Current Out High, IOH  
Current Out Low, IOL  
2.4  
±
3.5  
±.4  
V
V
mA  
mA  
4
4
Rev. B | Page 6 of 48  
 
Data Sheet  
AD9739  
AC SPECIFICATIONS  
VDDA = VDD33 = 3.3 V, VDDC = VDD = 1.8 V, IOUTFS = 20 mA, fDAC = 2400 MSPS.  
Table 4.  
Parameter  
Min  
Typ  
Max  
Unit  
DYNAMIC PERFORMANCE  
DAC Clock Rate  
8±±  
8±±  
25±±  
25±±  
MSPS  
MSPS  
ns  
Adjusted DAC Update Rate1  
Output Settling Time (tst) to ±.1%  
13  
SPURIOUS-FREE DYNAMIC RANGE (SFDR)  
fOUT = 1±± MHz  
fOUT = 35± MHz  
fOUT = 55± MHz  
fOUT = 95± MHz  
69.5  
58.5  
54  
dBc  
dBc  
dBc  
dBc  
6±  
TWO-TONE INTERMODULATION DISTORTION (IMD), fOUT2 = fOUT1 + 1.25 MHz  
fOUT = 1±± MHz  
fOUT = 35± MHz  
fOUT = 55± MHz  
fOUT = 95± MHz  
94  
78  
72  
68  
dBc  
dBc  
dBc  
dBc  
NOISE SPECTRAL DENSITY (NSD), ± dBFS SINGLE TONE  
fOUT = 1±± MHz  
fOUT = 35± MHz  
fOUT = 55± MHz  
fOUT = 85± MHz  
−166  
−161  
−16±  
−16±  
dBm/Hz  
dBm/Hz  
dBm/Hz  
dBm/Hz  
WCDMA ACLR (SINGLE CARRIER), ADJACENT/ALTERNATE ADJACENT CHANNEL  
fDAC = 2457.6 MSPS fOUT = 35± MHz  
fDAC = 2457.6 MSPS, fOUT = 95± MHz  
fDAC = 2457.6 MSPS, fOUT = 17±± MHz (Mix Mode)  
fDAC = 2457.6 MSPS, fOUT = 21±± MHz (Mix Mode)  
8±/8±  
78/79  
74/74  
69/72  
dBc  
dBc  
dBc  
dBc  
1 Adjusted DAC updated rate is calculated as fDAC divided by the minimum required interpolation factor. For the AD9739, the minimum interpolation factor is 1. Thus,  
with fDAC = 25±± MSPS, fDAC adjusted = 25±± MSPS.  
Rev. B | Page 7 of 48  
 
AD9739  
Data Sheet  
ABSOLUTE MAXIMUM RATINGS  
THERMAL RESISTANCE  
Table 5.  
θJA is specified for the worst-case conditions, that is, a device  
soldered in a circuit board for surface-mount packages.  
With  
Parameter  
Respect To Rating  
VDDA  
VDD33  
VSSA  
VSS  
−±.3 V to +3.6 V  
−±.3 V to +3.6 V  
Table 6. Thermal Resistance  
Package Type  
θJA  
θJC  
Unit  
°C/W1  
VDD  
VDDC  
VSSA  
VSS  
VSSC  
VSS  
−±.3 V to +1.98 V  
−±.3 V to +1.98 V  
−±.3 V to +±.3 V  
16±-Ball CSP_BGA  
1 With no airflow movement.  
31.2  
7.±  
VSSA  
VSS  
VSSC  
VSSC  
VSSC  
VSS  
−±.3 V to +±.3 V  
−±.3 V to +±.3 V  
−±.3 V to VDDC + ±.18 V  
−±.3 V to VDD33 + ±.3 V  
ESD CAUTION  
DACCLK_P, DACCLK_N  
DCI, DCO, SYNC_IN,  
SYNC_OUT  
LVDS Data Inputs  
IOUTP, IOUTN  
I12±, VREF  
IRQ, CS, SCLK, SDO,  
SDIO, RESET  
VSS  
−±.3 V to VDD33 + ±.3 V  
−1.± V to VDDA + ±.3 V  
−±.3 V to VDDA + ±.3 V  
−±.3 V to VDD33 + ±.3 V  
VSSA  
VSSA  
VSS  
Junction Temperature  
Storage Temperature  
15±°C  
−65°C to +15±°C  
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.  
Rev. B | Page 8 of 48  
 
Data Sheet  
AD9739  
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS  
1
2
3
4
5
6
7
8
9
10 11 12 13 14  
1
2
3
4
5
6
7
8
9 10 11 12 13 14  
A
B
C
D
E
F
A
B
C
D
E
F
G
H
J
G
H
J
K
L
K
L
M
N
P
M
N
P
VDDA, 3.3V, ANALOG SUPPLY  
VSSA, ANALOG SUPPLY GROUND  
VDDC, 1.8V, CLOCK SUPPLY  
VSSC, CLOCK SUPPLY GROUND  
VSSA SHIELD, ANALOG SUPPLY GROUND SHIELD  
Figure 4. Digital LVDS Clock Supply Pins (Top View)  
Figure 2. Analog Supply Pins (Top View)  
1
2
3
4
5
6
7
8
9 10 11 12 13 14  
1
2
3
4
5
6
7
8
9 10 11 12 13 14  
A
B
C
D
E
F
A
B
C
D
E
F
DACCLK_N  
DACCLK_P  
G
H
J
G
H
J
SYNC_OUT_P/_N  
SYNC_IN_P/_N  
DCO_P/_N  
DCI_P/_N  
K
L
K
L
DB1[0:13]P  
DB1[0:13]N  
DB0[0:13]P  
DB0[0:13]N  
M
N
P
M
N
P
DIFFERENTIAL INPUT SIGNAL (CLOCK OR DATA)  
VDD, 1.8V, DIGITAL SUPPLY  
VSS DIGITAL SUPPLY GROUND  
VDD33, 3.3V DIGITAL SUPPLY  
Figure 5. Digital LVDS Input, Clock I/O (Top View)  
Figure 3. Digital Supply Pins (Top View)  
Rev. B | Page 9 of 48  
 
AD9739  
Data Sheet  
1
2
3
4
5
6
7
8
9 10 11 12 13 14  
A
B
C
D
E
F
I120  
VREF  
IPTAT  
IRQ  
CS  
RESET  
SDIO  
SDO  
G
H
J
SCLK  
K
L
M
N
P
Figure 6. Analog I/O and SPI Control Pins (Top View)  
Table 7. AD9739 Pin Function Descriptions  
Pin No.  
Mnemonic  
Description  
C1, C2, D1, D2, E1, E2, E3, E4  
A1, A2, A3, A4, A5, B1, B2, B3, B4, B5, C4,  
C5, D4, D5  
VDDC  
VSSC  
1.8 V Clock Supply Input.  
Clock Supply Return.  
A1±, A11, B1±, B11, C1±, C11, D1±, D11  
A12, A13, B12, B13, C12, C13, D12, D13,  
VDDA  
VSSA  
3.3 V Analog Supply Input.  
Analog Supply Return.  
A6, A9, B6, B9, C6, C9, D6, D9, F1, F2, F3,  
F4, E11, E12, E13, E14, F11, F12  
VSSA Shield  
Analog Supply Return Shield. Tie to VSSA at the DAC.  
A14  
NC  
No Connect. Do not connect to this pin.  
DAC Negative Current Output Source.  
DAC Positive Current Output Source.  
Nominal 1.2 V Reference. Tie to analog ground via a 1± kΩ  
resistor to generate a 12± μA reference current.  
A7, B7, C7, D7  
A8, B8, C8, D8  
B14  
IOUTN  
IOUTP  
I12±  
C14  
VREF  
Voltage Reference Input/Output. Decouple to VSSA with a  
1 nF capacitor.  
D14  
C3, D3  
F13  
NC  
Factory Test Pin. Do not connect to this pin.  
Negative/Positive DAC Clock Input (DACCLK).  
Interrupt Request Open Drain Output. Active high. Pull up to  
VDD33 with a 1± kΩ resistor.  
DACCLK_N/DACCLK_P  
IRQ  
F14  
G13  
RESET  
CS  
Reset Input. Active high. Tie to VSS if unused.  
Serial Port Enable Input.  
G14  
H13  
H14  
SDIO  
SCLK  
SDO  
Serial Port Data Input/Output.  
Serial Port Clock Input.  
Serial Port Data Output.  
J3, J4, J11, J12  
G1, G2, G3, G4, G11, G12  
VDD33  
VDD  
3.3 V Digital Supply Input.  
1.8 V Digital Supply. Input.  
H1, H2, H3, H4, H11, H12, K3, K4, K11, K12 VSS  
Digital Supply Return.  
J1, J2  
SYNC_OUT_P/SYNC_OUT_N  
SYNC_IN_P/SYNC_IN_N  
DCO_P/DCO_N  
Positive/Negative SYNC Output (SYNC_OUT)  
Positive/Negative SYNC Input (SYNC_IN)  
Positive/Negative Data Clock Output (DCO).  
Positive/Negative Data Clock Input (DCI).  
Port 1 Positive/Negative Data Input Bit ±.  
Port 1 Positive/Negative Data Input Bit 1.  
Port 1 Positive/Negative Data Input Bit 2.  
Port 1 Positive/Negative Data Input Bit 3.  
Port 1 Positive/Negative Data Input Bit 4.  
Port 1 Positive/Negative Data Input Bit 5.  
K1, K2  
J13, J14  
K13, K14  
L1, M1  
L2, M2  
L3, M3  
L4, M4  
L5, M5  
L6, M6  
DCI_P/DCI_N  
DB1[±]P/DB1[±]N  
DB1[1]P/DB1[1]N  
DB1[2]P/DB1[2]N  
DB1[3]P/DB1[3]N  
DB1[4]P/DB1[4]N  
DB1[5]P/DB1[5]N  
Rev. B | Page 1± of 48  
Data Sheet  
AD9739  
Pin No.  
L7, M7  
L8, M8  
Mnemonic  
Description  
DB1[6]P/DB1[6]N  
DB1[7]P/DB1[7]N  
DB1[8]P/DB1[8]N  
DB1[9]P/DB1[9]N  
DB1[1±]P/DB1[1±]N  
DB1[11]P/DB1[11]N  
DB1[12]P/DB1[12]N  
DB1[13]P/DB1[13]N  
DB±[±]P/DB±[±]N  
DB±[1]P/DB±[1]N  
DB±[2]P/DB±[2]N  
DB±[3]P/DB±[3]N  
DB±[4]P/DB±[4]N  
DB±[5]P/DB±[5]N  
DB±[6]P/DB±[6]N  
DB±[7]P/DB±[7]N  
DB±[8]P/DB±[8]N  
DB±[9]P/DB±[9]N  
DB±[1±]P/DB±[1±]N  
DB±[11]P/DB±[11]N  
DB±[12]P/DB±[12]N  
DB±[13]P/DB±[13]N  
Port 1 Positive/Negative Data Input Bit 6.  
Port 1 Positive/Negative Data Input Bit 7.  
Port 1 Positive/Negative Data Input Bit 8.  
Port 1 Positive/Negative Data Input Bit 9.  
Port 1 Positive/Negative Data Input Bit 1±.  
Port 1 Positive/Negative Data Input Bit 11.  
Port 1 Positive/Negative Data Input Bit 12.  
Port 1 Positive/Negative Data Input Bit 13.  
Port ± Positive/Negative Data Input Bit ±.  
Port ± Positive/Negative Data Input Bit 1.  
Port ± Positive/Negative Data Input Bit 2.  
Port ± Positive/Negative Data Input Bit 3.  
Port ± Positive/Negative Data Input Bit 4.  
Port ± Positive/Negative Data Input Bit 5.  
Port ± Positive/Negative Data Input Bit 6.  
Port ± Positive/Negative Data Input Bit 7.  
Port ± Positive/Negative Data Input Bit 8.  
Port ± Positive/Negative Data Input Bit 9.  
Port ± Positive/Negative Data Input Bit 1±.  
Port ± Positive/Negative Data Input Bit 11.  
Port ± Positive/Negative Data Input Bit 12.  
Port ± Positive/Negative Data Input Bit 13.  
L9, M9  
L1±, M1±  
L11, M11  
L12, M12  
L13, M13  
L14, M14  
N1, P1  
N2, P2  
N3, P3  
N4, P4  
N5, P5  
N6, P6  
N7, P7  
N8, P8  
N9, P9  
N1±, P1±  
N11, P11  
N12, P12  
N13, P13  
N14, P14  
Rev. B | Page 11 of 48  
AD9739  
Data Sheet  
TYPICAL PERFORMANCE CHARACTERISTICS  
AC (NORMAL MODE)  
IOUTFS = 20 mA, nominal supplies, 25°C, unless otherwise noted.  
START 20MHz  
STOP 2.4GHz  
START 20MHz  
STOP 2.4GHz  
VBW 10kHz  
VBW 10kHz  
Figure 7. Single-Tone Spectrum at fOUT = 91 MHz, fDAC = 2.4 GSPS  
Figure 10. Single-Tone Spectrum at fOUT = 1091 MHz, fDAC = 2.4 GSPS  
80  
100  
1.2GSPS  
1.6GSPS  
75  
95  
1.2GSPS  
90  
70  
65  
2.0GSPS  
85  
80  
75  
60  
1.6GSPS  
70  
2.4GSPS  
55  
65  
2.0GSPS  
2.4GSPS  
60  
50  
45  
40  
35  
30  
55  
50  
45  
40  
35  
30  
0
100 200 300 400 500 600 700 800 900 1000 1100 1200  
fOUT (MHz)  
0
100 200 300 400 500 600 700 800 900 1000 1100 1200  
fOUT (MHz)  
Figure 8. SFDR vs. fOUT over fDAC  
Figure 11. IMD vs. fOUT over fDAC  
–160  
–161  
–162  
–163  
–164  
–165  
–166  
–167  
–168  
–169  
–170  
–150  
–152  
–154  
–156  
–158  
–160  
–162  
–164  
–166  
–168  
–170  
2.4GSPS  
2.4GSPS  
1.2GSPS  
1.2GSPS  
0
100 200 300 400 500 600 700 800 900 1000 1100 1200  
fOUT (MHz)  
0
100 200 300 400 500 600 700 800 900 1000 1100 1200  
fOUT (MHz)  
Figure 9. Single-Tone NSD over fOUT  
Figure 12. Eight-Tone NSD over fOUT  
Rev. B | Page 12 of 48  
 
Data Sheet  
AD9739  
fDAC = 2 GSPS, IOUTFS = 20 mA, nominal supplies, 25°C, unless otherwise noted.  
90  
110  
100  
90  
80  
–6dBFS  
–6dBFS  
–3dBFS  
70  
80  
70  
60  
0dBFS  
–3dBFS  
60  
0dBFS  
50  
50  
40  
30  
40  
30  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
Figure 16. IMD vs. fOUT over Digital Full Scale  
Figure 13. SFDR vs. fOUT over Digital Full Scale  
90  
80  
70  
60  
50  
40  
30  
90  
80  
70  
60  
50  
40  
30  
–6dBFS  
–6dBFS  
–3dBFS  
0dBFS  
–3dBFS  
0dBFS  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
Figure 17. SFDR for Third Harmonic over fOUT vs. Digital Full Scale  
Figure 14. SFDR for Second Harmonic over fOUT vs. Digital Full Scale  
110  
90  
100  
80  
20mA FS  
90  
80  
70  
60  
50  
40  
30  
30mA FS  
10mA FS  
70  
60  
50  
40  
30  
10mA FS  
20mA FS  
30mA FS  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
Figure 18. IMD vs. fOUT over DAC IOUTFS  
Figure 15. SFDR vs. fOUT over DAC IOUTFS  
Rev. B | Page 13 of 48  
AD9739  
Data Sheet  
90  
80  
70  
60  
50  
40  
110  
100  
90  
+85°C  
+85°C  
–40°C  
80  
70  
+25°C  
60  
–40°C  
+25°C  
50  
40  
30  
0
30  
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
Figure 19. SFDR vs. fOUT over Temperature  
Figure 22. IMD vs. fOUT over Temperature  
–150  
–152  
–154  
–156  
–158  
–160  
–162  
–164  
–166  
–168  
–150  
–152  
–154  
–156  
–158  
–160  
–162  
–164  
–166  
–168  
–170  
–40°C  
–40°C  
+85°C  
+25°C  
+85°C  
+25°C  
–170  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
0
100 200 300 400 500 600 700 800 900 1000  
fOUT (MHz)  
Figure 20. Single-Tone NSD vs. fOUT over Temperature  
Figure 23. Eight-Tone NSD vs. fOUT over Temperature  
–50  
–55  
–60  
–65  
–70  
–75  
–80  
–85  
–90  
FIRST ADJ CH  
SECOND ADJ CH  
FIFTH ADJ CH  
0
245.76 491.52  
122.88 368.64  
737.28  
983.04  
1228.80  
CENTER 350.27MHz  
#RES BW 30kHz  
SPAN 53.84MHz  
SWEEP 174.6ms (601pts)  
614.40  
860.16  
1105.90  
VBW 300kHz  
fOUT (MHz)  
FREQ  
REF  
RMS RESULTS  
CARRIER POWER  
–14.54dBm/  
OFFSET BW  
LOWER  
UPPER  
(MHz)  
5
(MHz) (dBc) (dBm) (dBc) (dBm)  
3.84 –79.90 –94.44 –79.03 –93.57  
3.84 –80.60 –95.14 –79.36 –94.40  
3.84 –80.90 –95.45 –80.73 –95.27  
3.84 –80.62 –95.16 –80.97 –95.51  
3.84 –80.76 –95.30 –80.95 –95.49  
10  
3.84MHz  
15  
20  
25  
Figure 24. Four-Carrier WCDMA at 350 MHz, fDAC = 2457.6 MSPS  
Figure 21. Single-Carrier WCDMA at 350 MHz, fDAC = 2457.6 MSPS  
Rev. B | Page 14 of 48  
Data Sheet  
AD9739  
AC (MIX MODE)  
fDAC = 2.4 GSPS, IOUTFS = 20 mA, nominal supplies, 25°C, unless otherwise noted.  
START 20MHz  
#RES BW 10kHz  
STOP 2.4GHz  
SWEEP 28.7s (601pts)  
START 20MHz  
#RES BW 10kHz  
STOP 2.4GHz  
SWEEP 28.7s (601pts)  
VBW 10kHz  
VBW 10kHz  
Figure 28. Single-Tone Spectrum in Mix Mode at fOUT = 1.31 GHz,  
fDAC = 2.4 GSPS  
Figure 25. Single-Tone Spectrum at fOUT = 2.31 GHz, fDAC = 2.4 GSPS  
80  
75  
70  
65  
60  
55  
50  
45  
40  
35  
30  
25  
20  
15  
90  
85  
80  
75  
70  
65  
60  
55  
50  
45  
40  
35  
10  
30  
1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400  
1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400  
fOUT (MHz)  
fOUT (MHz)  
Figure 26. SFDR in Mix Mode vs. fOUT at 2.4 GSPS  
Figure 29. IMD in Mix Mode vs. fOUT at 2.4 GSPS  
–40  
SECOND NYQUIST ZONE  
THIRD NYQUIST ZONE  
–45  
–50  
–55  
–60  
–65  
–70  
–75  
–80  
–85  
–90  
FIRST ADJ CH  
FIFTH ADJ CH  
SECOND ADJ CH  
CENTER 2.10706MHz  
#RES VW 30kHz  
SPAN 53.84MHz  
1229 1475 1720 1966 2212 2458 2703 2949 3195 3441 3686  
SWEEP 174.6ms (601pts)  
VBW 300kHz  
REF  
fOUT (MHz)  
FREQ  
RMS RESULTS  
CARRIER POWER  
–21.43dBm/  
OFFSET BW  
LOWER  
UPPER  
(MHz) (MHz) (dBc) (dBm) (dBc) (dBm)  
5
10  
15  
20  
25  
3.84 –68.99 –90.43 –63.94 –90.37  
3.84 –72.09 –93.52 –71.07 –92.50  
3.84 –72.86 –94.30 –71.34 –92.77  
3.84 –74.34 –95.77 –72.60 –94.03  
3.84 –74.77 –96.20 –73.26 –94.70  
3.84MHz  
Figure 27. Typical Single-Carrier WCDMA ACLR Performance at 2.1 GHz,  
fDAC = 2457.6 MSPS (Second Nyquist Zone)  
Figure 30. Single-Carrier WCDMA ACLR vs. fOUT at 2457.6 MSPS  
Rev. B | Page 15 of 48  
 
AD9739  
Data Sheet  
CENTER 2.81271GHz  
#RES BW 30kHz  
SPAN 63.84MHz  
CENTER 2.807GHz  
SPAN 53.84MHz  
SWEEP 207ms (601pts)  
#RES BW 30kHz  
SWEEP 174.6ms (601pts)  
VBW 300kHz  
REF  
VBW 300kHz  
FREQ  
OFFSET BW  
FREQ  
REF  
RMS RESULTS  
RMS RESULTS  
CARRIER POWER  
–24.4dBm/  
LOWER  
UPPER  
OFFSET BW  
LOWER  
UPPER  
(MHz) (MHz) (dBc) (dBm) (dBc) (dBm)  
CARRIER POWER  
–27.98dBm/  
3.84MHz  
(MHz)  
5
(MHz) (dBc) (dBm) (dBc) (dBm)  
3.84 –64.90 –89.30 –63.82 –88.22  
3.84 –66.27 –90.67 –65.70 –90.10  
3.84 –68.44 –92.84 –66.55 –90.95  
3.84 –70.20 –94.60 –68.95 –93.35  
3.84 –70.85 –95.25 –70.45 –94.85  
5
3.84 –0.42 –28.40 –0.10 –28.07  
3.84 –64.32 –92.30 –0.08 –28.06  
3.84 –66.03 –94.01 –65.37 –93.34  
3.84 –66.27 –94.24 –66.06 –94.03  
3.84 –66.82 –94.79 –63.36 –93.34  
3.84 –67.16 –95.13 –66.54 –94.51  
10  
15  
20  
25  
30  
10  
3.84MHz  
15  
20  
25  
Figure 33. Typical Four-Carrier WCDMA ACLR Performance at 2.8 GHz,  
fDAC = 2457.6 MSPS (Third Nyquist Zone)  
Figure 31. Typical Single-Carrier WCDMA ACLR Performance at 2.8 GHz,  
DAC = 2457.6 MSPS (Third Nyquist Zone)  
f
CENTER 2.09758GHz  
#RES BW 30kHz  
SPAN 63.84MHz  
SWEEP 207ms (601pts)  
VBW 300kHz  
REF  
FREQ  
RMS RESULTS  
CARRIER POWER  
–25.53dBm/  
OFFSET BW  
LOWER  
UPPER  
(MHz)  
5
(MHz) (dBc) (dBm) (dBc) (dBm)  
3.84  
0.22 –25.31  
3.84 –66.68 –92.21  
0.24 –25.29  
0.14 –25.38  
10  
3.84MHz  
15  
3.84 –68.01 –93.53 –66.82 –92.35  
3.84 –68.61 –94.14 –67.83 –93.36  
3.84 –68.87 –94.40 –67.64 –93.17  
3.84 –69.21 –94.74 –68.50 –94.03  
20  
25  
30  
Figure 32. Typical Four-Carrier WCDMA ACLR Performance at 2.1 GHz,  
fDAC = 2457.6 MSPS (Second Nyquist Zone)  
Rev. B | Page 16 of 48  
Data Sheet  
AD9739  
TERMINOLOGY  
Linearity Error (Integral Nonlinearity or INL)  
The maximum deviation of the actual analog output from the  
ideal output, determined by a straight line drawn from 0 to  
full scale.  
Power Supply Rejection (PSR)  
The maximum change in the full-scale output as the supplies  
are varied from nominal to minimum and maximum specified  
voltages.  
Differential Nonlinearity (DNL)  
The measure of the variation in analog value, normalized to full  
scale, associated with a 1 LSB change in digital input code.  
Spurious-Free Dynamic Range (SFDR)  
The difference, in decibels (dB), between the rms amplitude of  
the output signal and the peak spurious signal over the specified  
bandwidth.  
Monotonicity  
A DAC is monotonic if the output either increases or remains  
constant as the digital input increases.  
Total Harmonic Distortion (THD)  
The ratio of the rms sum of the first six harmonic components  
to the rms value of the measured input signal. It is expressed as  
a percentage or in decibels (dB).  
Offset Error  
The deviation of the output current from the ideal of 0 is called  
the offset error. For IOUTP, 0 mA output is expected when the  
inputs are all 0s. For IOUTN, 0 mA output is expected when all  
inputs are set to 1.  
Noise Spectral Density (NSD)  
NSD is the converter noise power per unit of bandwidth. This  
is usually specified in dBm/Hz in the presence of a 0 dBm  
full-scale signal.  
Gain Error  
The difference between the actual and ideal output span. The  
actual span is determined by the output when all inputs are set  
to 1 minus the output when all inputs are set to 0.  
Adjacent Channel Leakage Ratio (ACLR)  
The adjacent channel leakage (power) ratio is a ratio, in dBc, of the  
measured power within a channel relative to its adjacent channels.  
Output Compliance Range  
Modulation Error Ratio (MER)  
The range of allowable voltage at the output of a current output  
DAC. Operation beyond the maximum compliance limits may  
cause either output stage saturation or breakdown, resulting in  
nonlinear performance.  
Modulated signals create a discrete set of output values referred  
to as a constellation. Each symbol creates an output signal  
corresponding to one point on the constellation. MER is a  
measure of the discrepancy between the average output symbol  
magnitude and the rms error magnitude of the individual symbol.  
Temperature Drift  
Specified as the maximum change from the ambient (25°C)  
value to the value at either TMIN or TMAX. For offset and gain  
drift, the drift is reported in ppm of full-scale range (FSR)  
per °C. For reference drift, the drift is reported in ppm per °C.  
Intermodulation Distortion (IMD)  
IMD is the result of two or more signals at different frequencies  
mixing together. Many products are created according to the  
formula, aF1 bF2, where a and b are integer values.  
Rev. B | Page 17 of 48  
 
AD9739  
Data Sheet  
SERIAL PORT INTERFACE (SPI) REGISTER  
SPI REGISTER MAP DESCRIPTION  
SPI OPERATION  
The serial port of the AD9739 shown in Figure 34 has a 3- or  
4-wire SPI capability, allowing read/write access to all registers  
that configure the devices internal parameters. It provides a  
flexible, synchronous serial communications port, allowing easy  
interface to many industry-standard microcontrollers and  
microprocessors. The 3.3 V serial I/O is compatible with most  
synchronous transfer formats, including the Motorola® SPI and  
the Intel® SSR protocols.  
The AD9739 contains a set of programmable registers described  
in Table 10 that are used to configure and monitor various internal  
parameters. Note the following points when programming the  
AD9739 SPI registers:  
Registers pertaining to similar functions are grouped  
together and assigned adjacent addresses.  
Bits that are undefined within a register should be assigned  
a 0 when writing to that register.  
Registers that are undefined should not be written to.  
A hardware or software reset is recommended upon  
power-up to place SPI registers in a known state.  
A SPI initialization routine is required as part of the boot  
process. See Table 31 and Table 32 for example procedures.  
SDO (PIN H14)  
SDIO (PIN G14)  
AD9739  
SPI PORT  
SCLK (PIN H13)  
CS (PIN G13)  
Figure 34. AD9739 SPI Port  
Reset  
The default 4-wire SPI interface consists of a clock (SCLK), serial  
Issuing a hardware or software reset places the AD9739 SPI  
registers in a known state. All SPI registers (excluding 0x00) are  
set to their default states as described in Table 10 upon issuing a  
reset. After issuing a reset, the SPI initialization process need only  
write to registers that are required for the boot process as well as  
any other register settings that must be modified, depending on  
the target application.  
CS  
port enable ( ), serial data input (SDIO), and serial data output  
CS  
(SDO). The inputs to SCLK, , and SDIO contain a Schmitt  
trigger with a nominal hysteresis of 0.4 V centered about VDD33/2.  
The maximum frequency for SCLK is 20 MHz. The SDO pin is  
active only during the transmission of data and remains three-  
stated at any other time.  
A 3-wire SPI interface can be enabled by setting the SDIO_DIR  
bit (Register 0x00, Bit 7). This causes the SDIO pin to become  
bidirectional such that output data only appears on the SDIO  
pin during a read operation. The SDO pin remains three-stated  
in a 3-wire SPI interface.  
Although the AD9739 does feature an internal power-on-reset  
(POR), it is still recommended that a software or hardware reset  
be implemented shortly after power-up. The internal reset signal is  
derived from a logical OR operation from the internal POR  
signal, the RESET pin, and the software reset state. A software  
reset can be issued via the reset bit (Register 0x00, Bit 5) by  
toggling the bit high then low. Note that, because the MSB/LSB  
format may still be unknown upon initial power-up (that is,  
internal POR is unsuccessful), it is also recommended that the  
bit settings for Bits[7:5] be mirrored onto Bits[2:0] for the  
instruction cycle that issues a software reset. A hardware reset  
can be issued from a host or external supervisory IC by applying a  
high pulse with a minimum width of 40 ns to the RESET pin  
(that is, Pin F14). RESET should be tied to VSS if unused.  
Instruction Header Information  
MSB  
LSB  
1±  
A±  
17  
16  
A6  
15  
A5  
14  
A4  
13  
A3  
12  
A2  
11  
A1  
R/W  
An 8-bit instruction header must accompany each read and write  
operation. The MSB is a R/ indicator bit with logic high  
W
indicating a read operation. The remaining seven bits specify  
the address bits to be accessed during the data transfer portion.  
The eight data bits immediately follow the instruction header  
for both read and write operations. For write operations, registers  
change immediately upon writing to the last bit of each transfer  
Table 8. SPI Registers Pertaining to SPI Options  
Address (Hex)  
Bit  
Description  
CS  
byte.  
can be raised after each sequence of eight bits (except  
±x±±  
7
Enable 3-wire SPI  
Enable SPI LSB first  
Software reset  
the last byte) to stall the bus. The serial transfer resumes when  
6
CS  
is lowered. Stalling on nonbyte boundaries resets the SPI.  
5
Rev. B | Page 18 of 48  
 
 
Data Sheet  
AD9739  
The AD9739 serial port can support both most significant bit  
(MSB) first and least significant bit (LSB) first data formats.  
Figure 35 illustrates how the serial port words are formed for  
the MSB first and LSB first modes. The bit order is controlled  
by the SDIO_DIR bit (Register 0x00, Bit 7). The default value is 0,  
MSB first. When the LSB first bit is set high, the serial port  
interprets both instruction and data bytes LSB first.  
Figure 36 illustrates the timing requirements for a write operation  
CS  
to the SPI port. After the serial port enable ( ) signal goes low,  
data (SDIO) pertaining to the instruction header is read on the  
rising edges of the clock (SCLK). To initiate a write operation,  
the read/not-write bit is set low. After the instruction header is  
read, the eight data bits pertaining to the specified register are  
shifted into the SDIO pin on the rising edge of the next eight  
clock cycles.  
INSTRUCTION CYCLE  
DATA TRANSFER CYCLE  
CS  
Figure 37 illustrates the timing for a 3-wire read operation to  
SCLK  
CS  
the SPI port. After  
goes low, data (SDIO) pertaining to the  
R/W N1 N2 A4 A3 A2 A1 A0 D71 D61  
D1N D0N  
SDATA  
instruction header is read on the rising edges of SCLK. A read  
operation occurs if the read/not-write indicator is set high. After  
the address bits of the instruction header are read, the eight data  
bits pertaining to the specified register are shifted out of the SDIO  
pin on the falling edges of the next eight clock cycles.  
INSTRUCTION CYCLE  
DATA TRANSFER CYCLE  
CS  
SCLK  
Figure 38 illustrates the timing for a 4-wire read operation to  
the SPI port. The timing is similar to the 3-wire read operation  
with the exception that data appears at the SDO pin only, while the  
SDIO pin remains at high impedance throughout the operation.  
The SDO pin is an active output only during the data transfer  
phase and remains three-stated at all other times.  
SDATA  
A0 A1 A2 A3 A4 N2 N1 R/W D01 D11  
D6N D7N  
Figure 35. SPI Timing, MSB First (Upper) and LSB First (Lower)  
tS  
1/fSCLK  
tH  
CS  
tLOW  
tHI  
SCLK  
tDS  
tDS  
tDS  
tDH  
R/W  
N1  
N0  
A0  
D7  
D6 D1  
D0  
SDIO  
Figure 36. SPI Write Operation Timing  
tS  
1/fSCLK  
CS  
tLOW  
tHI  
SCLK  
tDV  
tDH  
tEZ  
A1  
A0  
D6 D1 D0  
N1  
D7  
A2  
SDIO  
R/W  
Figure 37. SPI 3-Wire Read Operation Timing  
tS  
1/fSCLK  
CS  
tLOW  
tHI  
SCLK  
tDH  
tEZ  
tEZ  
A1  
A0  
N1  
A2  
SDIO  
SDO  
R/W  
tDV  
D6 D1 D0  
D7  
Figure 38. SPI 4-Wire Read Operation Timing  
Rev. B | Page 19 of 48  
 
 
 
 
AD9739  
Data Sheet  
SPI REGISTER MAP  
Table 9. Full Register Map (N/A = Not Applicable)  
Hex  
Name  
Addr Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
N/A  
N/A  
Bit 2  
N/A  
N/A  
Bit 1  
Bit 0  
Default  
±x±±  
Mode  
±±  
±1  
SDIO_DIR  
LSB/MSB  
N/A  
Reset  
N/A  
N/A  
N/A  
Power-  
Down  
N/A  
N/A  
N/A  
N/A  
LVDS_  
DRVR_PD  
LVDS_  
RCVR_PD  
CLK_  
RCVR_PD  
DAC_  
BIAS_PD  
±x±±  
CNT_  
CLK_DIS  
±2  
±3  
N/A  
N/A  
N/A  
N/A  
N/A  
CLKGEN_PD  
MU_LST_EN  
N/A  
REC_CNT_  
CLK  
MU_CNT_  
CLK  
±x±3  
±x±±  
±x±±  
IRQ_EN  
SYNC_  
LST_EN  
SYNC_  
LCK_EN  
MU_LCK_EN  
RCV_  
LST_EN  
RCV_  
LCK_EN  
IRQ_REQ ±4  
SYNC_  
LST_IRQ  
SYNC_  
LCK_IRQ  
MU_LST_  
IRQ  
MU_LCK_  
IRQ  
RCVLST_  
IRQ  
RCVLCK_  
IRQ  
RSVD  
FSC_1  
FSC_2  
±5  
±6  
±7  
±8  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
FSC[7]  
Sleep  
N/A  
FSC[6]  
N/A  
FSC[5]  
N/A  
FSC[4]  
N/A  
FSC[3]  
N/A  
FSC[2]  
N/A  
FSC[1]  
FSC[±]  
±x±±  
±x±2  
±x±±  
FSC[9]  
FSC[8]  
DEC_  
CNT  
N/A  
N/A  
N/A  
N/A  
N/A  
DAC_DEC[1]  
DAC_DEC[±]  
RSVD  
±9  
±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  
LVDS_  
CNT  
HNDOFF_  
CHK_RST  
LVDS_  
Bias[1]  
LVDS_  
Bias[±]  
±x±±  
DIG_  
STAT  
±B  
±C  
±D  
HNDOFF_  
Fall[3]  
HNDOFF_  
Fall[2]  
HNDOFF_  
Fall[1]  
HNDOFF_  
Fall[±]  
HNDOFF_  
Rise[3]  
HNDOFF_  
Rise[2]  
HNDOFF_  
Rise[1]  
HNDOFF_  
Rise[±]  
RNDM  
LVDS_  
STAT1  
SUP/HLD_  
Edge1  
N/A  
DCI_  
PHS3  
DCI_  
PHS1  
DCI_PRE_  
PH2  
DCI_PRE_  
PH±  
DCI_PST_  
PH2  
DCI_PST_  
PH±  
RNDM  
LVDS_  
STAT2  
SUP/HLD_  
SYNC  
SUP/HLD_  
Edge±  
SYNC_  
SAMP1  
SYNC_  
SAMP±  
LVDS1_HI  
LVDS1_LO  
LVDS±_HI  
LVDS±_LO  
RNDM/±  
RSVD  
RSVD  
±E  
±F  
1±  
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  
N/A  
N/A  
N/A  
N/A  
±x42  
LVDS_  
REC_  
SYNC_  
FLG_RST  
SYNC_  
LOOP_ON  
SYNC_  
MST/SLV  
SYNC_  
CNT_ENA  
RCVR_  
FLG_RST  
RCVR_  
LOOP_ON  
RCVR_  
CNT_ENA  
CNT1  
LVDS_  
REC_  
CNT2  
11  
12  
13  
14  
15  
16  
17  
18  
19  
1A  
SMP_DEL[1]  
SMP_DEL[9]  
DCI_DEL[3]  
CLKDIVPH[1]  
SMP_  
DEL[±]  
FINE_  
DEL_  
MID[3]  
FINE_  
DEL_  
MID[2]  
FINE_DEL_  
MID[1]  
FINE_DEL_  
MID[±]  
RCVR_  
GAIN[1]  
RCVR_  
GAIN[±]  
±xDD  
±x29  
±x71  
±x±A  
±x42  
±x±±  
±x±±  
±x±±  
±xC7  
±x29  
LVDS_  
REC_  
CNT3  
SMP_  
DEL[8]  
SMP_  
DEL[7]  
SMP_  
DEL[6]  
SMP_  
DEL[5]  
SMP_  
DEL[4]  
SMP_  
DEL[3]  
SMP_  
DEL[2]  
LVDS_  
REC_  
CNT4  
DCI_  
DEL[2]  
DCI_  
DEL[1]  
DCI_  
DEL[±]  
FINE_DEL_  
SKW[3]  
FINE_DEL_  
SKW[2]  
FINE_DEL_  
SKW[1]  
FINE_DEL_  
SKW[±]  
LVDS_  
REC_  
CNT5  
CLKDIVPH[±] DCI_  
DEL[9]  
DCI_  
DEL[8]  
DCI_  
DEL[7]  
DCI_  
DEL[6]  
DCI_  
DEL[5]  
DCI_  
DEL[4]  
LVDS_  
REC_  
CNT6  
SYNC_  
GAIN[1]  
SYNC_  
GAIN[±]  
SYNCOUT_  
PH[1]  
SYNCOUT_ LCKTHR[3]  
PH[±]  
LCKTHR[2]  
LCKTHR[1]  
LCKTHR[±]  
LVDS_  
REC_  
CNT7  
N/A  
SYNCO_  
DEL[6]  
SYNCO_  
DEL[5]  
SYNCO_  
DEL[4]  
SYNCO_  
DEL[3]  
SYNCO_  
DEL[2]  
SYNCO_  
DEL[1]  
SYNCO_  
DEL[±]  
LVDS_  
REC_  
CNT8  
SYNCSH_  
DEL[±]  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
LVDS_  
REC_  
CNT9  
SYNCSH_  
DEL[8]  
SYNCSH_  
DEL[7]  
SYNCSH_  
DEL[6]  
SYNCSH_  
DEL[5]  
SYNCSH_  
DEL[4]  
SYNCSH_  
DEL[3]  
SYNCSH_  
DEL[2]  
SYNCSH_  
DEL[1]  
LVDS_  
REC_  
STAT1  
SMP_DEL[1]  
SMP_DEL[9]  
SMP_DEL[±]  
N/A  
N/A  
SMP_  
FINE_  
DEL[3]  
SMP_  
FINE_  
DEL[2]  
SMP_  
FINE_  
DEL[1]  
SMP_  
FINE_  
DEL[±]  
LVDS_  
REC_  
SMP_  
DEL[8]  
SMP_  
DEL[7]  
SMP_  
DEL[6]  
SMP_  
DEL[5]  
SMP_  
DEL[4]  
SMP_  
DEL[3]  
SMP_  
DEL[2]  
STAT2  
Rev. B | Page 2± of 48  
 
Data Sheet  
AD9739  
Hex  
Name  
Addr Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Default  
LVDS_  
REC_  
STAT3  
1B  
1C  
1D  
1E  
1F  
2±  
21  
DCI_DEL[1]  
DCI_DEL[±]  
N/A  
N/A  
SYNCOUT  
PH[1]  
SYNCOUT  
PH[±]  
CLKDIV  
PH[1]  
CLKDIV  
PH[±]  
±xC±  
LVDS_  
REC_  
STAT4  
DCI_DEL[9]  
DCI_  
DEL[8]  
DCI_  
DEL[7]  
DCI_  
DEL[6]  
DCI_  
DEL[5]  
DCI_  
DEL[4]  
DCI_  
DEL[3]  
DCI_  
DEL[2]  
±x29  
±x86  
±x±±  
±x±±  
±x±±  
±x±±  
LVDS_  
REC_  
STAT5  
FINE_DEL_  
PST[3]  
FINE_DEL_  
PST[2]  
FINE_DEL_  
PST[1]  
FINE_DEL_  
PST[±]  
FINE_DEL_  
PRE[3]  
FINE_DEL_  
PRE[2]  
FINE_DEL_  
PRE[1]  
FINE_DEL_  
PRE[±]  
LVDS_  
REC_  
STAT6  
N/A  
SYNCO_  
DEL[6]  
SYNCO_  
DEL[5]  
SYNCO_  
DEL[4]  
SYNCO_  
DEL[3]  
SYNCO_  
DEL[2]  
SYNCO_  
DEL[1]  
SYNCO_  
DEL[±]  
LVDS_  
REC_  
STAT7  
SYNCSH_  
DEL[±]  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
LVDS_  
REC_  
STAT8  
SYNCSH_  
DEL[8]  
SYNCSH_  
DEL[7]  
SYNCSH_  
DEL[6]  
SYNCSH_  
DEL[5]  
SYNCSH_  
DEL[4]  
SYNCSH_  
DEL[3]  
SYNCSH_  
DEL[2]  
SYNCSH_  
DEL[1]  
LVDS_  
REC_  
SYNC_  
TRK_ON  
SYNC_  
INIT_ON  
SYNC_  
LST_LCK  
SYNC_LCK  
RCVR_  
TRK_ON  
RCVR_  
FE_ON  
RCVR_LST  
RCVR_LCK  
STAT9  
CROSS_  
CNT1  
22  
23  
24  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
DIR_P  
DIR_N  
CLKP_  
OFFSET[3]  
CLKP_  
OFFSET[2]  
CLKP_  
OFFSET[1]  
CLKP_  
OFFSET[±]  
±x±±  
±x±±  
±x±±  
CROSS_  
CNT2  
N/A  
CLKN_  
OFFSET[3]  
CLKN_  
OFFSET[2]  
CLKN_  
OFFSET[1]  
CLKN_  
OFFSET[±]  
PHS_  
DET  
CMP_BST  
PHS_DET  
AUTO_EN  
Bias[3]  
Bias[2]  
Bias[1]  
Bias[±]  
MU_  
DUTY  
25  
26  
27  
MU_  
DUTYAUTO_EN  
POS/NEG  
Slope  
ADJ[5]  
ADJ[4]  
ADJ[3]  
Read  
ADJ[2]  
ADJ[1]  
ADJ[±]  
±x±±  
±x42  
±x4±  
MU_  
CNT1  
N/A  
Mode[1]  
Mode[±]  
Gain[1]  
Gain[±]  
Enable  
MU_  
MUDEL[±]  
SRCH_MODE SRCH_MODE SET_PHS[4] SET_PHS[3]  
SET_PHS[2]  
SET_PHS[1]  
SETPHS[±]  
CNT2  
[1]  
[±]  
MU_  
CNT3  
28  
29  
2A  
MUDEL[8]  
SEARCH_TOL  
N/A  
MUDEL[7]  
MUDEL[6]  
MUDEL[5]  
Guard[4]  
N/A  
MUDEL[4]  
Guard[3]  
N/A  
MUDEL[3]  
Guard[2]  
N/A  
MUDEL[2]  
Guard[1]  
MU_LOST  
MUDEL[1]  
Guard[±]  
MU_LKD  
±x±±  
±x±B  
±x±±  
MU_  
CNT4  
Retry  
N/A  
CONTRST  
N/A  
MU_  
STAT1  
RSVD  
RSVD  
2B  
2C  
32  
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  
N/A  
N/A  
N/A  
ANA_  
CNT1  
HDRM[7]  
HDRM[6]  
HDRM[5]  
HDRM[4]  
HDRM[3]  
HDRM[2]  
HDRM[1]  
HDRM[±]  
±xCA  
ANA_  
CNT2  
33  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
MSEL[1]  
MSEL[±]  
±x±3  
RSVD  
34  
35  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
N/A  
PART ID  
ID[7]  
ID[6]  
ID[5]  
ID[4]  
ID[3]  
ID[2]  
ID[1]  
ID[±]  
±x2±  
Rev. B | Page 21 of 48  
AD9739  
Data Sheet  
SPI PORT CONFIGURATION AND SOFTWARE RESET  
Table 10. SPI Port Configuration and Software Reset Register  
Address  
(Hex)  
Default  
Name  
Bit R/W Setting Comments  
±x±±  
SDIO_DIR  
LSB/MSB  
Reset  
7
6
5
R/W  
R/W  
R/W  
±
±
±
± = 4-wire SPI, 1 = 3-wire SPI.  
± = MSB first, 1 = LSB first.  
Software reset is recommended before modification of other SPI registers from the default  
setting. Setting the bit to 1 causes all registers (except ±x±±) to be set to the default setting.  
Setting the bit to ± corresponds to the inactive state, allowing the user to modify registers  
from the default setting.  
POWER-DOWN LVDS INTERFACE AND TXDAC®  
Table 11. Power-Down LVDS Interface and TxDAC Register  
Address  
(Hex)  
Default  
Setting  
Name  
Bit  
5
R/W  
R/W  
R/W  
R/W  
R/W  
Comments  
±x±1  
LVDS_DRVR_PD  
LVDS_RCVR_PD  
CLK_RCVR_PD  
DAC_BIAS_PD  
±
±
±
±
Power-down of the LVDS drivers/receivers and TxDAC.  
± = enable, 1 = disable.  
4
1
±
CONTROLLER CLOCK DISABLE  
Table 12. Controller Clock Disable Register  
Address  
(Hex)  
Default  
Setting  
Name  
Bit  
R/W  
Comments  
±x±2  
CLKGEN_PD  
3
R/W  
±
Internal CLK distribution enable:  
± = enable, 1 = disable.  
REC_CNT_CLK  
MU_CNT_CLK  
1
±
R/W  
R/W  
1
1
LVDS receiver and Mu controller clock disable.  
± = disable, 1 = enable.  
INTERRUPT REQUEST (IRQ) ENABLE/STATUS  
Table 13. Interrupt Request (IRQ) Enable/Status Register  
Address  
(Hex)  
Default  
Name  
Bit R/W Setting Comments  
±x±3  
SYNC_LST_EN  
SYNC_LCK_EN  
MU_LST_EN  
MU_LCK_EN  
RCV_LST_EN  
RCV_LCK_EN  
SYNC_LST_IRQ  
SYNC_LCK_IRQ  
MU_LST_IRQ  
MU_LCK_IRQ  
RCV_LST_IRQ  
RCV_LCK_IRQ  
5
4
3
2
1
±
5
4
3
2
1
±
W
W
W
W
W
W
R
±
±
±
±
±
±
±
±
±
±
±
±
This register enables the sync, mu, and LVDS Rx controllers to update their  
corresponding IRQ status bits in Register ±x±4, which defines whether the controller is  
locked (LCK) or unlocked (LST).  
± = disable (resets the status bit).  
1 = enable.  
±x±4  
This register indicates the status of the controllers. For LCK_IQR bits: ± = lost locked, 1  
= locked. For LST_IQR bits: ± = not lost locked, 1 = unlocked. Note that, if the  
controller IRQ is serviced, the relevant bits in Register ±x±3 should be reset by writing  
±, followed by another write of 1 to enable.  
R
R
R
R
R
Rev. B | Page 22 of 48  
 
 
Data Sheet  
AD9739  
TxDAC FULL-SCALE CURRENT SETTING (IOUTFS) AND SLEEP  
Table 14. TxDAC Full-Scale Current Setting (IOUTFS) and Sleep Register  
Address  
(Hex)  
Default  
Setting  
Name  
FSC_1  
FSC_2  
Sleep  
Bit  
[7:±]  
[1:±]  
7
R/W  
R/W  
R/W  
R/W  
Comments  
±x±6  
±x±7  
±x±±  
±x±2  
Sets the TxDAC IOUTFS current between 8 mA and 31 mA (default = 2± mA).  
I
OUTFS = ±.±226 × FSC[9:±] + 8.58, where FSC = ± to 1±23.  
± = enable DAC output, 1 = disable DAC output (sleep).  
TxDAC QUAD-SWITCH MODE OF OPERATION  
Table 15. TxDAC Quad-Switch Mode of Operation Register  
Address  
(Hex)  
Default  
Setting  
Name  
Bit  
R/W  
Comments  
±x±8  
DAC-DEC  
[1:±]  
R/W  
±x±±  
±x±± = normal baseband mode.  
±x±1 = return-to-zero mode.  
±x±2 = mix mode.  
DCI PHASE ALIGNMENT STATUS  
Table 16. DCI Phase Alignment Status Register  
Address  
(Hex)  
Default  
Bit R/W Setting  
Name  
Comments  
±x±C  
DCI_PRE_PH±  
2
R
±
±
± = DCI rising edge is after the PRE delayed version of the Phase ± sampling edge.  
1 = DCI rising edge is before the PRE delayed version of the Phase ± sampling edge.  
DCI_PST_PH±  
±
R
± = DCI rising edge is after the POST delayed version of the Phase ± sampling edge.  
1 = DCI rising edge is before the POST delayed version of the Phase ± sampling edge.  
SYNC_IN PHASE ALIGNMENT STATUS  
Table 17. SYNC_IN Phase Alignment Status Register  
Address  
(Hex)  
Default  
Setting  
Name  
Bit  
R/W  
Comments  
±x±D  
SYNC_IN_PH9±  
5
R
±
± = SYNCIN rising edge is after Phase 9± sampling edge.  
1 = SYNCIN rising edge is before Phase 9± sampling edge.  
SYNC_IN_PH±  
4
R
±
± = SYNCIN rising edge is after Phase ± sampling edge.  
1 = SYNCIN rising edge is before Phase ± sampling edge.  
DATA RECEIVER CONTROLLER CONFIGURATION  
Table 18. Data Receiver Controller Configuration Register  
Address  
(Hex)  
Default  
Name  
Bit R/W Setting Comments  
±x1±  
SYNC_FLG_RST  
SYNC_LOOP_ON  
7
6
W
±
1
Sync controller flag reset. Write 1 followed by ± to reset flags.  
R/W  
± = disable, 1 = enable. Enable for master only. When enabled, sync controller  
generates an IRQ when master falls out of lock and automatically begins  
search/track routine.  
SYNC_MST/SLV  
SYNC_CNT_ENA  
RCVR_FLG_RST  
RCVR_LOOP_ON  
5
4
2
1
R/W  
R/W  
W
±
±
±
1
Sync controller configuration. ± = slave, 1 = master.  
Sync controller enable. ± = disable, 1 = enable  
Data receiver controller flag reset. Write 1 followed by ± to reset flags.  
R/W  
± = disable, 1 = enable. When enabled, the data receiver controller generates an IRQ;  
it falls out of lock and automatically begins a search/track routine.  
RCVR_CNT_ENA  
±
R/W  
±
Data receiver controller enabled. ± = disable, 1 = enable.  
Rev. B | Page 23 of 48  
 
AD9739  
Data Sheet  
DATA RECEIVER CONTROLLER_DATA SAMPLE DELAY VALUE  
Table 19. Data Receiver Controller_Data Sample Delay Value Register  
Address  
(Hex)  
Default  
R/W Setting Comments  
Name  
Bit  
±x11  
SMP_DEL[1:±] [7:6] R/W 11  
Controller enabled: the 1±-bit value (with a maximum of 332) represents the start  
value for the delay line used by the state machine to sample data. Leave at the default  
setting of 167, which represents the midpoint of the delay line. Controller disabled:  
the value sets the actual value of the delay line.  
±x12  
SMP_DEL[9:2] [7:±] R/W ±x25  
DATA AND SYNC RECEIVER CONTROLLER_DCI DELAY VALUE/WINDOW AND PHASE ROTATION  
Table 20. Data and Sync Receiver Controller_DCI Delay Value/Window and Phase Rotation Register  
Address  
(Hex)  
Default  
R/W Setting Comments  
Name  
Bit  
±x13  
DCI_DEL[3:±]  
FINE_DEL_SKEW  
[7:4] R/W ±111  
[3:±] R/W ±±±1  
Refer to the DCI_DEL description in Register ±x14.  
A 4-bit value sets the difference (that is, window) for the DCI PRE and POST  
sampling clocks. Leave at the default value of 1 for a narrow window.  
±x14  
CLKDIVPH[1:±]  
DCI_DEL[9:4]  
[7:6] R/W ±±  
Relative phase of internal div-by-4 circuit. This feature allows phase rotation in 9±°  
increments (that is, 1 count) to extend Rx controllers locking range for clock rates  
between ±.8 GSPS to 1.6 GSPS (only valid with sync controller disabled).  
[5:±] R/W ±±1±1± Controller enabled: the 1±-bit value (with a maximum of 332) represents the start  
value for the delay line used by the state machine to sample the DCI input. Leave  
at the default setting of 167, which represents the midpoint of the delay line.  
Controller disabled: the value sets the actual value of the delay line.  
±x15  
SYNC GAIN[1:±]  
[7:6] R/W ±±  
Sets the sync tracking gain (optimal value is 1).  
SYNCOUT_PH[1:±] [5:4] R/W ±±  
Readback of the present SYNC_OUT phase selection.  
LCKTHR[3:±]  
[3:±] R/W ±±±±  
[6:±] R/W ±x±±  
Sets the difference between the sample and DCI delays to lock (optimal value is 2).  
±x16  
±x17  
±x18  
SYNCO_DEL[6:±]  
SYNCSH_DEL[±]  
Sets the sync output delay value when the synch controller is disabled; otherwise,  
is the read status of the sync output delay value when sync is enabled.  
[7]  
R/W ±x±±  
Sets the sync setup and hold delay value when the synch controller is disabled;  
otherwise, is the read status of sync setup and hold value when sync is enabled.  
SYNCSH_DEL[8:1] [7:±] R/W ±x±±  
Sets the sync setup and hold delay value when the synch controller is disabled;  
otherwise, is the read status of sync setup and hold value when sync is enabled.  
DATA RECEIVER CONTROLLER_DELAY LINE STATUS AND SYNC CONTROLLER SYNC_OUT STATUS  
Table 21. Data Receiver Controller_Delay Line Status and Sync Controller SYNC_OUT Status Register  
Address  
(Hex)  
Default  
R/W Setting Comments  
Name  
Bit  
±x19  
±x1A  
±x1B  
SMP_DEL[1:±]  
SMP_DEL[9:2]  
[7:6]  
[7:±]  
R
R
R
R
R
R
±±  
The actual value of the DCI and data delay lines determined by the data receiver  
controller (when enabled) after the state machine completes its search and enters  
track mode. Note that these values should be equal.  
SYNCOUT_PH provides phase status (±/9±/18±/27±) of phase select mux, while  
CLKDIVPH provides phase status of data receiver controller (Register ±x14).  
±x±±  
±±  
SYNCOUT_PH[1:±] 3:2  
CLKDIV PH[1:±]  
DCI_DEL[1:±]  
DCI_DEL[9:2]  
1:±  
±±  
[7:6]  
[7:±]  
±±  
±x1C  
±x±±  
Rev. B | Page 24 of 48  
 
Data Sheet  
AD9739  
SYNC AND DATA RECEIVER CONTROLLER LOCK/TRACKING STATUS  
Table 22. Sync and Data Receiver Controller Lock/Tracking Status Register  
Address  
(Hex)  
Default  
Setting  
Name  
Bit  
7
R/W  
R
Comments  
±x21  
SYNC_TRK_ON  
SYNC_LST  
SYNC_LCK  
RCVR_TRK_ON  
RCVR_LST  
±
±
±
±
±
SYNC_TRK_ON and RCVR_TRK_ON:  
± = tracking not established.  
1 = tracking established.  
SYNC_LCK and RCVR_LCK:  
± = controller is not locked.  
1 = controller is locked.  
5
R
4
R
3
R
1
R
SYNC_LST and RCVR_LST:  
± = lock has not been lost.  
1 = lock has been lost at some point.  
RCVR_LCK  
±
R
±
CLK INPUT COMMON MODE  
Table 23. CLK Input Common Mode Register  
Address  
(Hex)  
Default  
R/W Setting Comments  
R/W  
DIR_P and DIR_N:  
Name  
Bit  
±x22  
DIR_P  
4
±
± = VCM at the DACCLK_P input decreases with the offset value.  
1 = VCM at the DACCLK_P input increases with the offset value.  
CLKx_OFFSET sets the magnitude of the offset for the DACCLK_P and DACCLK_N  
inputs. For optimum performance, set to 1111.  
CLKP_OFFSET[3:±] [3:±] R/W ±±±±  
DIR_N R/W  
CLKN_OFFSET[3:±] [3:±] R/W ±±±±  
±x23  
4
±
MU CONTROLLER CONFIGURATION AND STATUS  
Table 24. Mu Controller Configuration and Status Register  
Address  
(Hex)  
Default  
R/W Setting Comments  
Name  
Bit  
±x24  
CMP_BST  
5
R/W  
±
Phase detector enable and boost bias bits. Note that both bits should always be set to 1  
to enable these functions.  
PHS_DET  
AUTO_EN  
4
7
6
R/W  
±
±x25  
±x26  
MU_DUTY  
AUTO_EN  
R/W  
R/W  
±
1
Mu controller duty cycle enable. Note that this bit should always be set to 1 to enable.  
Slope  
Mu controller phase slope lock. ± = negative slope, 1 = positive slope.  
Refer to Table 28 for optimum setting.  
Mode[1:±]  
[5:4] R/W ±±  
Sets the mu controller mode of operation.  
±± = search and track (recommended).  
±1 = search only.  
1± = track.  
Read  
3
R/W  
±
Set to 1 to read the current value of the Mu delay line in.  
Gain[1:±]  
Enable  
[2:1] R/W ±1  
Sets the mu controller tracking gain. Recommended to leave at the default ±1 setting.  
±
7
R/W  
R/W  
±
1 = enable the mu controller.  
± = disable the mu controller.  
±x27  
MUDEL[±]  
±
±
The LSB of the 9-bit MUDEL setting.  
SRCH_MODE[1:±] [6:5] R/W  
Sets the direction in which the mu controller searches (from its initial MUDEL setting) for  
the optimum mu delay line setting that corresponds to the desired phase/slope setting  
(that is, SET_PHS and slope ).  
±± = down.  
±1 = up.  
1± = down/up (recommended).  
SET_PHS[4:±]  
[4:±] R/W  
±
Sets the target phase that the mu controller locks to with a maximum setting of 16.  
Refer to Table 28 for optimum setting.  
Rev. B | Page 25 of 48  
 
AD9739  
Data Sheet  
Address  
(Hex)  
Default  
R/W Setting Comments  
Name  
Bit  
±x28  
MUDEL[8:1]  
[7:±]  
W
±x±±  
With enable (Bit ±, Register ±x26) set to ±, this 9-bit value represents the value that  
the mu delay is set to. Note that the maximum value is 432.  
With enable set to 1, this value represents the mu delay value at which the  
controller begins its search. Setting this value to the delay line midpoint of 216 is  
recommended.  
R
±x±±  
When read (Bit 3, Register ±x26) is set to 1, the value read back is equal to the value  
written into the register when enable = ± or the value that the mu controller locks  
to when enable = 1.  
±x29  
SEARCH_TOL  
Retry  
7
6
5
R/W  
R/W  
R/W  
±
±
±
± = not exact (can find a phase within two values of the desired phase).  
1 = finds the exact phase that is targeted (optimal setting).  
± = stop the search if the correct value is not found.  
1 = retry the search if the correct value is not found.  
CONTRST  
Controls whether the controller resets or continues when it does not find the  
desired phase.  
± = continue (optimal setting).  
1 = reset.  
Guard[4:±]  
4
R/W ±1±11  
Sets a guard band from the beginning and end of the mu delay line which the mu  
controller does not enter into unless it does not find a valid phase outside the  
guard band (optimal value is Decimal 11 or ±x±B).  
±x2A  
MU_LST  
MU_LKD  
1
±
R
R
±
±
± = mu controller has not lost lock.  
1 = mu controller has lost lock.  
± = mu controller is not locked.  
1= mu controller is locked.  
PART ID  
Table 25. Part ID Register  
Default  
Setting  
Address (Hex)  
Name  
Bit  
R/W  
Comments  
±x35  
PART_ID  
[7:±]  
R
±x2±  
Part ID number.  
Rev. B | Page 26 of 48  
 
Data Sheet  
AD9739  
THEORY OF OPERATION  
Figure 39 shows a top-level functional diagram of the AD9739.  
A high performance TxDAC core delivers a signal dependent,  
differential current (nominal 10 mA) to a balanced load  
referenced to ground. The frequency of the clock signal  
appearing at the AD9739 differential clock receiver, DACCLK,  
sets the TxDAC’s update rate. This clock signal, which serves as  
the master clock, is routed directly to the TxDAC as well as to a  
clock distribution block that generates all critical internal and  
external clocks.  
The AD9739 data receiver controller generates an internal  
sampling clock offset by 90° from the DCI to sample the input  
data on the DB0 and DB1 ports. When enabled and configured  
properly for track mode, it ensures proper data recovery between  
the host and the AD9739 clock domains. The data receiver  
controller has the ability to track several hundreds of ps of drift  
between these clock domains, typically caused by supply and  
temperature variation.  
As mentioned, the host processor provides the AD9739 with a  
deinterleaved data stream such that the DB0 and DB1 data ports  
receive alternating samples (that is, odd/even data streams). The  
AD9739 data assembler is used to reassemble (that is, multiplex)  
the odd/even data streams into their original order before  
delivery into the TxDAC for signal reconstruction. The pipeline  
delay from a sample being latched into the data port to when it  
appears at the DAC output is on the order of 78 ( ) DACCLK  
cycles. Applications that require matching pipeline delays (that  
is, synchronization) between multiple AD9739s can use the  
SYNC controller. The SYNC controller phase aligns the outputs  
of one or more AD9739 devices (that is,. slaves) to a master  
AD9739 device.  
RESET  
IRQ  
AD9739  
1.2V  
SDIO  
SDO  
CS  
SPI  
DAC BIAS  
VREF  
I120  
SCLK  
IOUTP  
IOUTN  
TxDAC  
CORE  
DCI  
The AD9739 includes a delay lock loop (DLL) circuit controlled  
via a mu controller to optimize the timing hand-off between the  
AD9739 digital clock domain and TxDAC core. Besides ensuring  
proper data reconstruction, the TxDACs ac performance is also  
dependent on this critical hand-off between these clock domains  
with speeds of up to 2.5 GSPS. Once properly initialized and  
configured for track mode, the DLL maintains optimum timing  
alignment over temperature, time, and power supply variation.  
CLK DISTRIBUTION  
(DIV-BY-4)  
DCO  
SYNC_OUT  
SYNC_IN  
SYNC-  
CONTROLLER  
DACCLK  
Figure 39. Functional Block Diagram of the AD9739  
A SPI interface is used to configure the various functional blocks as  
well as monitor their status for debug purposes. Proper operation  
of the AD9739 requires that controller blocks be initialized upon  
power-up. A simple SPI initialization routine is used to configure  
the controller blocks (see Figure 51 and Figure 52). An IRQ  
output signal is available to alert the host should any of the  
controllers fall out of lock during normal operation.  
The AD9739 includes two 14-bit LVDS data ports (DB0 and  
DB1) to reduce the data interface rate to ½ the TxDAC update rate.  
The host processor drives deinterleaved data with offset binary  
format onto the DB0 and DB1 ports, along with an embedded DCI  
clock that is synchronous with the data. Because the interface is  
double data rate (DDR), the DCI clock is essentially an alternating  
010101……….01010 bit pattern with a frequency equal to ¼ the  
TxDAC update rate (fDAC). To simplify synchronization with the  
host processor, the AD9739 passes an LVDS clock output (DCO)  
that is also equal to the DCI frequency.  
The following sections discuss the various functional blocks in  
more detail as well as their implications when interfacing to  
external ICs and circuitry. While a detailed description of the  
various controllers (and associated SPI registers used to configure  
and monitor) is also included for completeness, the recommended  
SPI boot procedure can be used to ensure reliable operation.  
Rev. B | Page 27 of 48  
 
 
AD9739  
Data Sheet  
The maximum allowable skew and jitter out of the host  
processor with respect to the DCI clock edge on each LVDS  
port is calculated as  
LVDS DATA PORT INTERFACE  
The AD9739 supports input data rates from 1.6 GSPS to 2.5 GSPS  
using dual LVDS data ports. The interface is source synchronous  
and double data rate (DDR) where the host provides an embedded  
data clock input (DCI) at fDAC/4 with its rising and falling edges  
aligned with the data transitions. The data format is offset binary;  
however, twos complement format can be realized by reversing  
the polarity of the MSB differential trace. As shown in Figure 40,  
the host feeds the AD9739 with deinterleaved input data into  
two 14-bit LVDS data ports (DB0 and DB1) at ½ the DAC clock  
rate (that is, fDAC/2). The AD9739 internal data receiver controller  
then generates a phase shifted version of DCI to register the  
input data on both the rising and falling edges.  
MaxSkew + Jitter = Period(ns) − ValidWindow(ps) − Guard  
= 800 ps − 344 ps − 100 ps  
= 356 ps  
where ValidWindow(ps) is represented by tVALID and Guard is  
represented by tGUARD in Figure 41.  
The minimum specified LVDS valid window is 344 ps, and a  
guard band of 100 ps is recommended. Therefore, at the maximum  
operating frequency of 2.5 GSPS, the maximum allowable FPGA  
and PCB bit skew plus jitter is equal to 356 ps.  
HOST  
PROCESSOR  
AD9739  
For synchronous operation, the AD9739 provides a data clock  
output, DCO, to the host at the same rate as DCI (that is, fDAC/4)  
to maintain the lowest skew variation between these clock  
domains. Since the DCO signal is generated from a separate  
clock divider, its phase relationship relative to the fDAC/4 clocks  
used by the data receiver controller will vary upon each power-up.  
EVEN DATA  
SAMPLES  
14 × 2  
fDATA  
= fDAC/2  
Applications sensitive to this phase ambiguity (resulting in a  
DACCLK pipeline variation) should consider using the sync  
controller.  
2
ODD DATA  
SAMPLES  
14 × 2  
The host processor has a worst-case skew between DCO and  
DCI that is both implementation and process dependent. This  
1 × 2  
DCI  
fDCI  
=
fDAC/4  
1 × 2  
fDCO fDAC/4  
worst-case skew can also vary an additional 30% over temperature  
and supply corners. The delay line within the data receiver  
controller can track a 1.5 ns skew variation after initial lock.  
While it is possible for the host to have an internal PLL that  
generates a synchronous fDAC/4 from which the DCI signal is  
derived, digital implementations that result in the shortest  
propagation delays result in the lowest skew variation.  
DCO  
fDAC  
DIV-BY-4  
=
Figure 40. Recommended Digital Interface Between the AD9739 and  
Host Processor  
As shown in Figure 41, the DCI clocks edges must be coincident  
with the data bit transitions with minimum skew, jitter, and  
intersymbol interference. To ensure coincident transitions with the  
data bits, the DCI signal should be implemented as an additional  
data line with an alternating (010101…) bit sequence from the  
same output drivers used for the data. Maximizing the opening  
of the eye in both the DCI and data signals improves the reliability  
of the data port interface. Differential controlled impedance traces  
of equal length (that is, delay) should also be used between the  
host processor and AD9739 input to limit bit-to-bit skew.  
The data receiver controller is used to ensure proper data hand-off  
between the host and AD9739 internal digital clock domains.  
The circuit shown in Figure 42 functions as a delay lock loop in  
which a 90o phase shifted version of the DCI clock input is used  
to sample the input data into the DDR receiver registers. This  
ensures that the sampling instance occurs in the middle of the  
data pattern eyes (assuming matched DCI and DBx[13:0] delays).  
Note that, because the DCI delay and sample delay clocks are  
derived from the div-by-4 circuitry, this 90° phase relationship  
holds as long as the delay settings (that is, DCI_DEL, SMP_DEL)  
are also matched.  
2 × 1/f  
DAC  
DCI  
tVALID  
+ tGUARD  
MAX SKEW  
+ JITTER  
tVALID  
DB0[13:0]  
AND DB1[13:0]  
Figure 41. LVDS Data Port Timing Requirements  
Rev. B | Page 28 of 48  
 
 
 
Data Sheet  
AD9739  
DATA RECEIVER CONTROLLER  
DCI WINDOW PRE  
DDR  
FF  
DCI  
FINE  
DELAY  
DELAY  
DELAY  
DCI  
DELAY  
PATH  
FROM SYNC CONTROLLER  
PRE  
OR  
SPI REG 0x14, BIT[7:6]  
PHASE  
ROTATION  
DCI DELAY  
DDR  
FF  
DCI WINDOW POST  
0
90  
STATE MACHINE/  
TRACKING LOOP  
FINE  
DELAY  
DIV-BY-4  
180  
F
DAC  
270  
POST  
SAMPLE  
DELAY  
DCI WINDOW SAMPLE  
DDR  
FF  
TO SYNC  
CONTROLLER  
SAMPLE  
DELAY  
PATH  
FINE  
DELAY  
DELAY  
DELAY  
SAMPLE  
DATA TO  
CORE  
DDR  
FF  
DDR  
FF  
DDR  
FF  
DDR  
FF  
DBx[13:1]  
ELASTIC FIFO  
DCO  
DIV-BY-4  
Figure 42. Top Level Diagram of the Data Receiver Controller  
The div-by-4 circuit generates four clock phases that serve as inputs  
to the data receiver controller. All of the DDR registers in the data  
and DCI paths operate on both clock edges; however, for clarity  
purposes, only the phases (that is, 0o and 90o) corresponding to  
the positive edge of each path are shown. One of the div-by-4  
phases is used to generate the DCO signal; therefore, the phase  
relationship between DCO and clocks fed into the controller  
remains fixed. Note that it is this attribute that allows possible  
factory calibration of images and clock spurs attributed to fDAC/4  
modulation of the critical DAC clock.  
Proper sampling of the DCI signal can also be confirmed by  
monitoring the status of DCI_PRE_PH0 (Register 0x0C, Bit 2)  
and DCI_PST_PH0 (Register 0x0C, Bit 0). If the delay settings  
are correct, the state of DCI_ PRE_PH0 should be 0, and the  
state of DCI_PST_PH0 should be 1. Note that the states of these  
status bits may toggle occasionally due to cycle-to cycle jitter  
exceeding the window width. However, the controller averages  
these status bits over multiple clock cycles to ensure that the  
DCI signal falls within a programmable window.  
DCI  
FINE DELAY  
PST  
Once this data has been successively sampled into the first set  
of registers, an elastic FIFO is used to transfer the data into  
the AD9739 clock domain. To continuously track any phase  
variation between the two clock domains, the data receiver  
controller should always be enabled and placed into track  
mode (Register 0x10, Bit 1 and Bit 0). Tracking mode operates  
continuously in the background to track delay variations between  
the host and AD9739 clock domains. It does so by ensuring that  
the DCI signal is sampled within a very narrow window defined  
by two internally generated clocks (that is, PRE and PST), as  
shown in Figure 43.  
FINE DELAY  
PRE  
FINE_DEL_SKEW  
Figure 43. Pre- and Post-Delay Sampling Diagram  
The skew or window width (FINE_DEL_SKEW) is set via  
Register 0x13, Bits[3:0], with a maximum skew of approximately  
180 ps and resolution of 12 ps. It is recommended that the skew  
be set to 36 ps (that is, Register 0x13 = 0x72) during initialization.  
The skew setting also affects the speed of the controller loop,  
with tighter skew settings corresponding to longer response time.  
Rev. B | Page 29 of 48  
 
 
AD9739  
Data Sheet  
synchronization controller (optional), the data receiver controller  
should be enabled only after these other controllers have been  
enabled and established locked. All of the internal controllers  
operate at submultiples of the DAC update rate. The number of  
Data Receiver Controller Initialization Description  
The data controller should be initialized and placed into track  
mode as the second step in the SPI boot sequence. The following  
steps are recommended for the initialization of the data receiver  
controller:  
f
DAC clock cycles required to lock onto the DCI clock is dependent  
on whether the synchronization controller is enabled as shown  
in Table 26.  
1. Set FINE_DEL_SKEW to 2 for a larger DCI sampling  
window (Register 0x13 = 0x72). Note that the default  
DCI_DEL and SMP_DEL settings of 167 are optimum.  
2. Disable the controller before enabling (that is, Register  
0x10 = 0x00).  
Table 26. Typical/Worst-Case Lock Times for LVDS Controller  
(Relative to 1/fDAC  
)
Synchronization Controller  
Typical  
7±K  
Worst Case  
135K  
Off  
3. Enable the Rx controller in two steps: Register 0x10 = 0x02  
followed by Register 0x10 = 0x03.  
4. Wait 135K clock cycles.  
Slave  
Master  
7±K  
3±±K  
135K  
56±K  
5. Read back Register 0x21 and confirm that it is equal to  
0x05 to ensure that the DLL loop is locked and tracking.  
During the SPI initialization process, the user has the option of  
polling Register 0x21 (Bit 0, Bit 1, and Bit 3) to determine if the  
data receiver controller is locked, has lost lock, or has entered into  
track mode before completing the boot sequence. Alternatively, the  
appropriate IRQ bit (Register 0x03 and Register 0x04) can be  
enabled such that an IRQ output signal is generated upon the  
controller establishing lock (see the Interrupt Requests section).  
6. Include this step for operation <1.6 GSPS. Read back the  
DCI_DEL value to determine whether the value falls  
within a user-defined tracking guard band. If it does not,  
rotate CLKDIVPH by 1 (Register 0x14, Bits[7:6] and go  
back to Step 2.  
The data receiver controller can also be configured to generate  
an interrupt request (IRQ) upon losing lock. Losing lock can be  
caused by excessive jitter on the DCI input signal, disruption of  
the main DAC clock input, or loss of a power supply rail. To service  
the interrupt, the host can poll the RCVR_LCK bit (Register 0x21,  
Bit 0) to determine the current state of the controller. If this bit  
is cleared, the search/track procedure can be restarted by setting  
the RCVR_LOOP_ON bit in Register 0x10, Bit 1. After waiting  
the required lock time, the host can poll the RCVR_LCK bit to  
see if it has been set. Before leaving the interrupt routine, the  
RCVR_FLG_RST bit (Register 0x10, Bit 2) should be reset by  
writing a high followed by a low.  
Once the controller is enabled during the initial SPI boot  
process (see Table 31 and Table 32), the controller enters a  
search mode where it seeks to find the closest rising edge of the  
DCI clock (relative to a delayed version of an internal fDAC/4 clock)  
by simultaneously adjusting the delays in the clocks used to  
register the DCI and data inputs. A state machine searches  
above and below the initial DCI_DEL value. The state machine  
first searches for the first rising edge above the DCI_DEL and  
then searches for the first rising edge below the DCI_DEL value.  
The state machine selects the closest rising edge and then enters  
track mode. It is recommended that the default midscale delay  
setting (that is, Decimal 167) for the DCI_DEL and SMP_DEL  
bits be kept to ensure that the selected edge remains closest to  
the delay line midpoint, thus providing the greatest range for  
tracking timing variations and preventing the controller from  
falling out of lock.  
Data Receiver Operation at Lower Clock Rates  
At clock rates below 1.6 GSPS, it is recommended to include  
provisions to rotate the CLKDIVPH setting in the SPI boot  
process. As previously mentioned, the delay line can be varied  
over a nominal 4 ns window. If the minimum specified clock  
rate of 800 MSPS is considered, a DCI clock rate of 200 MSPS  
corresponds to a 5 ns period, thus exceeding the delay line length.  
Therefore, it becomes possible that the initial startup phase from  
the div-by-4 circuit (and DCO output) is such that the data receiver  
controller can never establish initial lock upon power up.  
The adjustable delay span for these internal clocks (that is, DCI  
and sample delay) is nominally 4 ns. The 10-bit delay value is  
user programmable from the decimal equivalent code (0 to 384)  
with approximately 12 ps/LSB resolution via the DCI_DEL and  
SMP_DEL registers (via Register 0x11 thru Register 0x14). When  
the controller is enabled, it overwrites these registers with the  
delay value it converges upon. The minimum difference  
between this delay value and the minimum/maximum values  
(that is, 0 and 334) represents the guard band for tracking.  
Therefore, if the controller initially converges upon a DCI_DEL  
and SMP_DEL value between 80 and 304, the controller has a  
guard band of at least 80 code (approximately 1 ns) to track  
phase variations between the clock domains.  
If the clock rate is increased to 1600 MSPS (that is, DCI clock  
period of 2.5 ns), the controller will always be able to find at  
least two DCI clock edges, therefore, establish lock. However,  
should the DCI edges fall symmetrically (equal distance) from  
the initial DCI_DEL midscale setting, a guard band of 0.75 ns  
(that is, (4.0 − 2.5)/2) results. Rotating the CLKDIVPH can result  
in an improvement in this case by skewing one of the DCI edges  
toward the DCI_DEL midscale value.  
Upon initialization of the AD9739, a certain period of time is  
required for the data receiver controller to lock onto the DCI clock  
signal. Note that, due to its dependency on the mu controller and  
Rev. B | Page 3± of 48  
 
Data Sheet  
AD9739  
Rotating the CLKDIVPH phase provides a means of adjusting  
the delay in course steps of fDAC/4. For example, in the 800 MSPS  
and 1600 MSPS cases described above, rotating the CLKDIVPH  
setting by 1 corresponds to a delay shift of 5 ns and 2.5 ns,  
respectively. By adding an additional step in the SPI initialization  
routine for the data receiver controller, it becomes possible to  
increase the effective range of the delay line to ensure a  
DCI_DEL value that falls within a reasonable guard band.  
LVDS INPUTS  
(NO FAIL-SAFE)  
V
LVDS  
V
100  
COM  
= (V + V )/2  
P,N  
RECEIVER  
P
N
V
V
P
N
GND  
EXAMPLE  
LVDS Driver and Receiver Input  
V
V
1.4V  
P
The AD9739 features a LVDS-compatible driver and receivers.  
The LVDS driver output used for the DCO and SYNC_OUT  
signal includes an equivalent 200 Ω source resistor that limits its  
nominal output voltage swing to 200 mV when driving a  
100 Ω load. The DCO output driver can be powered down via  
Register 0x01, Bit 5. An equivalent circuit is shown in Figure 44  
VDD33  
1.0V  
0.4V  
N
V
P
N
0V  
–0.4V  
V
LOGIC 1  
LOGIC BIT  
EQUIVALENT  
LOGIC 0  
Figure 46. LVDS Data Input Levels  
V+  
ESD  
V–  
V–  
ESD  
V+  
VDD33 = 3.3V  
100100Ω  
DCO_P  
DCO_N  
R1  
VCM  
V
= 1.4V  
P
LVDS_1  
LVDS_2  
100  
100Ω  
VSS  
Figure 44. Equivalent LVDS Output  
VDD33  
LVDS_N  
100Ω  
V
= 1.4V  
100  
P
R2  
DCI_P  
DBx[13:0]P  
DCI_N  
DBx[13:0]N  
ESD  
ESD  
R1 = 4.75 × 100/N  
R2 = 2.50 × 100/N  
Figure 47. Resistor Network to Bias Unused LVDS Data Inputs  
The AD9739 LVDS inputs do not include fail-safe capability.  
Any unused data input pins should be biased with an external  
network or static driver. Figure 47 shows an external biasing  
network that can be used to place unused data bits into a known  
state. The resistor values for R1 and R2 are selected to establish  
a VP and VN of 1.4 V and 1.0 V, respectively, depending on the  
number of unused digital inputs, N.  
VSS  
Figure 45. Equivalent LVDS Input  
The LVDS receivers include 100 Ω termination resistors, as  
shown in Figure 45. These receivers meet the IEEE-1596.3-1996  
reduced swing specification (with the exception of input hysteresis,  
which cannot be guaranteed over all process corners). Figure 46  
and Figure 47 show an example of nominal LVDS voltage levels  
seen at the input of the differential receiver with resulting common-  
mode voltage and equivalent logic level. The LVDS receivers  
can be powered down via Register 0x01, Bit 4.  
Table 27. Example of LVDS Input Levels  
Applied Voltages  
VP (V) VN (V)  
1.4 1.±  
Resulting Differential Voltage  
Resulting Common-Model Voltage  
VP, N  
VCOM  
Logic Bit Binary Equivalent  
+±.4 V  
−±.4 V  
+2±± mV  
−2±± mV  
1.2 V  
1.2 V  
9±± mV  
9±± mV  
1
±
1
±
1.±  
1.±  
±.8  
1.4  
±.8  
1.±  
Rev. B | Page 31 of 48  
 
 
 
 
AD9739  
Data Sheet  
Figure 49 maps the typical mu phase characteristic at 2.4 GSPS vs.  
the 9-bit digital delay setting (MUDEL). The mu phase scaling  
is such that a value of 16 corresponds to 180 degrees. The critical  
keep-out window between the digital and analog domains occurs  
at a value of 0 (but can extend out to 2 depending on the clock  
rate). The target mu phase (and slope) is selected to provide  
optimum ac performance while ensuring that the mu controller  
for any device can establish and maintain lock. For example,  
while a slope and phase setting of −6 is considered optimum  
for operation between 1.6 GSPS and 2.5 GSPS, other values are  
required below 1.6 GSPS.  
MU CONTROLLER  
A delay lock loop (DLL) is used to optimize the timing between  
the internal digital and analog domains of the AD9739 such that  
data is successfully transferred into the TxDAC core at rates of  
up to 2.5 GSPS. As shown in Figure 48, the DAC clock is split  
into an analog and a digital path with the critical analog path  
leading to the DAC core (for minimum jitter degradation) and  
the digital path leading to a programmable delay line. Note that  
the output of this delay line serves as the master internal digital  
clock from which all other internal and external digital clocks  
are derived. The amount of delay added to this path is under the  
control of the mu controller, which optimizes the timing between  
these two clock domains and continuously tracks any variation  
(once in track mode) to ensure proper data hand-off.  
18  
NOM_P1  
SLOW_P1  
FAST_P1  
16  
14  
12  
10  
8
14-BIT  
DATA  
14-BIT  
DATA  
IOUTP  
IOUTN  
DIGITAL  
ANALOG  
CIRCUITRY  
CIRCUITRY  
MU  
DELAY  
PHASE  
DETECTOR  
6
MU  
DAC  
CLOCK  
DELAY  
4
CONTROLLER  
2
0
Figure 48. Mu Delay Controller Block Diagram  
0
40  
80 120 160 200 240 280 320 360 400 440  
DELAY LINE TAP  
The mu controller adjusts the timing relationship between the  
digital and analog domains via a tapped digital delay line having  
a nominal total delay of 864 ps. The delay value is programmable  
to a 9-bit resolution (that is, 0 to 432 decimal) via the MUDEL  
register, resulting in a nominal resolution of 2 ps/LSB. Because a  
time delay maps to a phase offset for a fixed clock frequency,  
the control loop essentially compares the phase relationship  
between the two clock domains and adjusts the phase (that is, via a  
tapped delay line) of the digital clock such that it is at the desired  
fixed phase offset (SET_PHS) from the critical analog clock.  
18  
Figure 50. Mu Phase Characteristics of Three Devices from Different Process  
Lots at 1.2 GSPS  
The mu phase characteristics can vary significantly among devices  
due to gm variations in the digital delay line that are sensitive to  
process skews (along with temperature and supply). As a result,  
careful selection of the target phase location is required such  
that the mu controller can converge upon this phase location  
for all devices. Figure 50 shows that mu phase characteristics of  
three devices at 25°C from slow, nominal, and fast skew lots at  
1.2 GSPS. Note that a −6 mu phase setting does not map to any  
delay line tap setting for the fast process skew case; therefore,  
another target mu phase is recommended at this clock rate.  
16  
GUARD  
BAND  
GUARD  
BAND  
14  
12  
10  
8
Table 28 provides a list of recommended mu phase/slope settings  
over the specified clock range of the AD9739 based on the  
considerations previously described. These values should be  
used to ensure robust operation of the mu controller.  
DESIRED  
PHASE  
6
Table 28. Recommended Target Mu Phase Settings vs. Clock Rate  
Clock Rate (GSPS)  
Slope  
MU Phase  
4
±.8  
±.9  
1.±  
1.1  
1.2  
1.3  
1.4  
1.5  
+
+
+
6
4
5
8
12  
12  
1±  
8
SEARCH STARTING  
LOCATION  
2
0
0
40  
80 120 160 200 240 280 320 360 400 440  
MU DELAY  
Figure 49. Typical Mu Phase Characteristic Plot at 2.4 GSPS  
1.6 to 2.5  
6
Rev. B | Page 32 of 48  
 
 
 
 
 
Data Sheet  
AD9739  
After the mu controller completes its search and establishes lock  
on the target mu phase, it attempts to maintain a constant timing  
relationship between the two clock domains over the specified  
temperature and supply range. If the mu controller requests a  
mu delay setting that exceeds the tapped delay line range (that  
is, <0 or >432), the mu controller can lose lock, causing possible  
system disruption (that is, can generate IRQ or restart the search).  
To avoid this scenario, symmetrical guard bands are recommended  
at each end of the mu delay range. The guard band scaling is  
such that one LSB of Guard[4:0] (Register 0x29) corresponds to  
eight LSBs of MUDEL (Register 0x28). The recommended guard  
band setting of 11 (that is, Register 0x29 = 0xCB) corresponds  
to 88 LSBs, thus providing sufficient margin.  
If everything matches, the search algorithm is finished. If not,  
the search continues in both directions until an exact match can  
be found or a programmable guard band is reached in one of  
the directions. When the guard band is reached, the search still  
continues but only in the opposite direction. If the desired phase is  
not found before the guard band is reached in the second direction,  
the search changes back to the alternating mode and continues  
looking within the guard band. The typical locking time for the mu  
controller is approximately 180K DAC cycles (at 2 GSPS ~ 75 μs).  
The search fails if the mu delay controller reaches the endpoints.  
The mu controller can be configured to retry (Register 0x29, Bit 6)  
the search or stop. For applications that have a microcontroller,  
the preferred approach is to poll the MU_LKD status bit  
(Register 0x2A, Bit 0) after the typical locking time has expired.  
This method allows the system controller to check the status of  
other system parameters (that is, power supplies and clock source)  
before reattempting the search (by writing 0x03 to Register 0x26).  
For applications that do not have polling capabilities, the mu  
controller state machine should be reconfigured to restart the  
search in hopes that the system’s condition that did not cause  
locking on the first attempt has disappeared.  
Mu Controller Initialization Description  
The mu controller must be initialized and placed into track  
mode as a first step in the SPI boot sequence. The following  
steps are required for initialization of the mu controller. Note  
that the AD9739 data sheet specifications and characterization  
data are based on the following mu controller settings:  
1. Turn on the phase detector with boost (Register 0x24 = 0x30).  
2. Enable the mu delay controller duty-cycle correction  
circuitry and specify the recommended slope for phase.  
(that is, Register 0x25 = 0x80 corresponds to a negative slope).  
3. Specify search/track mode with a recommended target  
phase, SET_PHS, of 6 (for example) and an initial  
MUDEL[8:0] setting of 216 (Register 0x27 = 0x46 and  
Register 0x28 = 0x6C).  
4. Set search tolerance to exact and retry if the search fails  
its initial attempt. Also, set the guard band to the  
recommended setting of 11 (Register 0x29 = 0xCB).  
5. Set the mu controller tracking gain to the recommended  
setting and enable the mu controller state machine  
(Register 0x26 = 0x03).  
Once the mu delay value is found that exactly matches the desired  
mu phase setting and slope (for example, 6 with a negative.  
slope), the mu controller goes into track mode. In this mode,  
the mu controller makes slight adjustments to the delay value  
to track any variations between the two clock paths due to  
temperature, time, and supply variations. Two status bits,  
MU_LKD (Register 0x2A, Bit 0) and MU_LST (Register 0x2A,  
Bit 1) are available to the user to signal the existing status control  
loop. If the current phase is more than four steps away from the  
desired phase, the MU_LKD bit is cleared, and if the lock  
acquired was previously set, the MU_LST bit is set. Should the  
phase deviation return to within three steps, the MU_LKD bit is  
set again while the MU_LST is cleared. Note that this sort of event  
may occur if the main clock input (that is, DACCLK) is disrupted  
or the mu controller exceeds the tapped delay line range (that is,  
<0 or >432).  
Upon completion of the last step, the mu controller begins a  
search algorithm that starts with an initial delay setting specified  
by the MUDEL register (that is, 216, which corresponds to the  
midpoint of the delay line). The initial search algorithm works  
by sweeping through different mu delay values in an alternating  
manner until the desired phase (that is, a SET_PHS of 4) is  
exactly measured. When the desired phase is measured, the  
slope of the phase measurement is then calculated and  
If lock is lost, the mu controller has the option of remaining in  
the tracking loop or resetting and starting the search again via  
the CONTRST bit (Register 0x29, Bit 5). Continued tracking is  
the preferred state because it is the least disruptive to a system  
in which the AD9739 temporarily loses lock. The user can poll  
the mu delay and phase value by first setting the read bit high  
(Register 0x26, Bit 3). Once the read bit is set, the MUDEL[8:0]  
bits and the SET_PHS[4:0] bits (Register 0x27 and Register 0x28)  
that the controller is currently using can be read.  
compared against the specified slope (slope = negative).  
Rev. B | Page 33 of 48  
AD9739  
Data Sheet  
It is also possible to use the IRQ during the AD9739 initialization  
phase after power-up to determine when the mu and data receiver  
controllers have achieved lock. For example, before enabling the  
mu controller, the MU_LCK_EN bit (Register 0x03, Bit 2) can be  
set and the IRQ output signal monitored to determine when lock  
has been established before continuing in a similar manner with  
the data receiver controllers. Note that the relevant LCK bit should  
be cleared before continuing to the next controller. After all  
controllers are locked, the lost lock enable bits (that is, x_LST_EN)  
should be set.  
INTERRUPT REQUESTS  
The AD9739 can provide the host processor with an interrupt  
request output signal (IRQ) that indicates that one or more of the  
AD9739 internal controllers have achieved lock or lost lock. These  
controllers include the mu, data receiver, and synchronization  
controllers. The host can then poll the IRQ status register  
(Register 0x04) to determine which controller has lost lock.  
The IRQ output signal is an active high output signal available  
on Pin F13. If used, its output should be connected via a 10 kꢀ  
pull-up resistor to VDD33.  
Table 29. Interrupt Request Registers  
Each IRQ is enabled by setting the enable bits in Register 0x03,  
which purposely has the same bit mapping as the IRQ status  
bits in Register 0x04. Note that these IRQ status bits are set only  
when the controller transitions from a false to true state. Therefore,  
it is possible for the x_LCK_IRQ and x_LST_IRQ status bits to  
be set when a controller temporarily loses lock but is able to  
reestablish lock before the IRQ is serviced by the host. In this  
case, the host should validate the present status of the suspect  
controller by reading back its current status bits, which are  
available in Register 0x21 and/or Register 0x2A. Based on the  
status of these bits, the host can take appropriate action, if required,  
to reestablish lock. To clear an IRQ after servicing, it is necessary to  
reset relevant bits in Register 0x03 by writing 0 followed by  
another write of 1 to reenable. A detailed diagram of the  
interrupt circuitry is shown in Figure 51.  
Address (Hex)  
Bit  
5
4
3
2
1
±
5
4
3
2
1
±
7
5
4
3
1
±
1
±
Description  
SYNC_LST_EN  
SYNC_LCK_EN  
MU_LST_EN  
MU_LCK_EN  
RCV_LST_EN  
RCV_LCK_EN  
SYNC_LST_IRQ  
SYNC_LCK_IRQ  
MU_LST_IRQ  
MU_LCK_IRQ  
RCV_LST_IRQ  
RCV_LCK_IRQ  
SYNC_TRK_ON  
SYNC_LST  
±x±3  
±x±4  
±x21  
±x2A  
SYNC_LCK  
(PIN F13)  
SPI ISR  
INT  
D
INT(n)  
SOURCE  
SPI  
DATA  
RCVR_TRK_ON  
RCVR_LST  
Q
READ DATA  
RCVR_LCK  
INT  
SOURCE  
MU_LST  
SPI WRITE  
SCLK  
SPI ADDRESS  
MU_LKD  
IMR  
DATA = 1  
Figure 51. Interrupt Request Circuitry  
Rev. B | Page 34 of 48  
 
 
 
Data Sheet  
AD9739  
One AD9739 is designated as the master providing a SYNC_OUT  
reference clock (equal to fDAC/4) to itself as well as the other  
AD9739 slave device’s SYNC_IN input. LVDS fanout buffers with  
matched output delays are again used to distribute the SYNC_OUT  
and DCO signals of the master to the slave devices and FPGAs,  
respectively, thus ensuring tight time alignment. Note, in the  
case of a single FPGA implementation (that is, I/Q application),  
the DCO of the master can drive the FPGA directly.  
MULTIPLE DEVICE SYNCHRONIZATION  
Synchronization of multiple AD9739s requires all of the devices  
to have matching pipeline delays. This implies the DAC outputs  
are time aligned to the same phase when all devices are fed with  
the same data pattern at the same instance of time. The main  
contributor to phase ambiguity between devices is from the  
div-by-4 circuitry that drives the Rx data path and data controller  
(see Figure 53). This phase ambiguity can result in a 2 sample  
offset between any two devices. Because the state of this internal  
divider is unknown at power-up, a synchronization method that  
phase aligns the digital paths of multiple AD9739s is required to  
ensure matching pipeline delays.  
After synchronization, the internal div-by-4 circuitry will have  
equal phases that drive their respective LVDS controllers. Note,  
the mu and data receiver controller of both devices must be  
configured for the same SPI register settings (that is, SET_PHS  
and DCI_DEL) upon SPI initialization such that controllers  
converge to similar delays. To validate that delays are roughly  
matched, the user can read back the delays of both devices (that is,  
MUDEL and DCI_DEL) to determine if they are in an acceptable  
window that accounts for slight mismatches between different  
devices’ delay lines.  
Figure 52 shows a top-level diagram of multiple AD9739s  
synchronized to each other with sample alignment of the  
different data streams within the FPGA (or among multiple  
FPGAs) being assumed. A common RF clock source is  
distributed to each of the AD9739 devices via a dual clock  
buffer (such as the ADCLK946) with matched PCB trace  
lengths to each device to ensure matched propagation delays.  
MATCHED DELAYS  
1:N  
LVDS  
TO FPGA_2  
TO OTHER FPGAs  
REPEATER  
MATCHED DELAYS  
COMMON  
CLOCK SOURCE  
0.8GHz TO 2.0GHz  
ADCLK346  
TO SLAVE_1  
TO SLAVE_N  
DCO  
DACCLK  
AD9739  
MASTER  
DCI  
SYNC_IN SYNC_OUT  
MATCHED DELAYS  
FPGA_1  
1:N  
LVDS  
REPEATER  
DCO  
DACCLK  
AD9739  
SLAVE_1  
DCI  
SYNC_OUT SYNC_IN  
DCO  
MASTER  
DCO  
DCO  
DACCLK  
AD9739  
SLAVE_N  
DCI  
FPGA_2  
SYNC_OUT SYNC_IN  
Figure 52. Functional Block Diagram of Two AD9739s Synchronized  
Rev. B | Page 35 of 48  
 
 
AD9739  
Data Sheet  
DB0[13:0]  
DB0  
EVEN  
DB0  
ODD  
TO DAC  
DB1[13:0]  
DCI  
DB1  
EVEN  
DB1  
ODD  
fDAC DISTRIBUTION  
90/270  
0/180  
DELAY  
DELAY  
fDAC/4  
DIV-BY-4  
MU DELAY  
fDAC  
STATE MACHINE  
TRACKING LOOP  
RX DATA CONTROLLER  
PHASE  
ROTATOR  
SLAVE ONLY  
SYNCHRONIZATION CONTROLLER  
PHASE  
COMPARISON  
SYNC_IN  
0
0
90  
90  
SYNC_OUT  
DELAY  
180  
270  
STATE MACHINE  
TRACKING LOOP  
DIV-BY-4  
DCO  
Figure 53. Top Level Block Diagram of Synchronization Circuitry and Controller  
Figure 53 shows a top-level diagram of the synchronization  
controller (bottom) and how it interfaces to other digital  
functional blocks within the AD9739. Note the following  
observations of this top level diagram:  
It is not possible to manually rotate the div-by-4 phases of  
the data path with the sync controller enabled. This can be  
a problem at lower clock rates were one may desire to rotate  
the div-by-4 phase to ensure locking of the data receiver  
controller and/or achieve a more optimum DCI_DEL value.  
The DCO output signal is generated from a separate div-  
by-4 circuit, and therefore, has a random phase upon each  
startup. For this reason, the DCO of the master should be  
distributed to all the FPGAs.  
Synchronization between multiple devices is achieved by  
rotating the div-by-4 phases of the slave devices such that  
they align with the master.  
For the slave devices, the sync controller compares the phase  
alignment of the masters SYNC_IN reference signal with  
the initial 0o/90o outputs of the div-by-4 and then rotates  
the div-by-4 phase until the SYNC_IN signal falls between  
these phases.  
SYNC Controller Initialization Description  
The sync controller of the master is enabled by writing 0x70 to  
Register 0x10. Once enabled, a state machine automatically adjusts  
the output delay of its SYNC_OUT signal such that the fed back  
reference SYNC_IN signal is centered between the 0° and 90°  
output phases associated with its div-by-4 circuit. Note that the  
coarse delay is performed by shifting phases via PHZ MUX while  
the fine delay that centers (and tracks) variation is done by a  
variable delay line. The variable delay line tap size is 12 ps. Once  
SYNC_IN is centered, the controller enters tracking mode such  
that SYNC_IN remains centered despite possible system variations  
in temperature and/or supply. Centering the SYNC_IN signal  
on the master device ensures that the SYNC_IN signals of the slave  
A reference signal common to all devices is required for  
synchronization. The master device generates this signal by  
providing a SYNC_OUT signal which is then distributed to  
all the devices (including itself with tight time alignment)  
as a SYNC_IN signal.  
Because the SYNC_IN signal has a defined relationship  
between the div-by-4 phase of the master, the slave devices can  
now align their respective div-by-4 phases to the SYNC_IN  
phase thus ensuring phase alignment among all devices.  
Rev. B | Page 36 of 48  
 
 
Data Sheet  
AD9739  
devices also remain centered between their respective div-by-4  
phases; therefore, providing the greatest margin to absorb nonideal  
timing skews. The following status bits are available in Register  
0x21 indicating lock, lost-lock, and tracking: SYNC_LCK,  
SYNC_LST and SYNC_TRK_ON.  
These sources of timing skews become more significant as the  
DACCLK period is decreased (that is, clock rate is increased),  
leaving less margin for timing skews external to the master-to-  
slave device(s). Special consideration to PCB layout and selection  
of clock distribution ICs are required to ensure minimum skew  
between the distributed DACCLK and SYNC_IN signals. Note  
that timing skews can quickly accumulate considering that the  
propagation delay on an FR4 PCB is on the order of 170 ps/inch,  
and that output-to-output skews on each clock distribution IC  
can be as high as 25 ps.  
The sync controller of the slave is enabled by writing 0x50 to  
Register 0x10. Once enabled, the state machine compares the  
reference SYNC_IN signal to the 0°/90° phase outputs of the  
div-by-4 phase settings. If the SYNC_IN signal does not fall  
between these phases, the state machine of the slave rotates the div-  
by-4 phase setting until it does. To validate that phase alignment  
has been achieved, the SYNC_IN_PH90 and SYNC_IN_PH0  
status bits should read 1 and 0, respectively (that is, Register 0x0D,  
Bits[5:4]). Note that the DCO and SYNC_OUT outputs of the  
slave can be disabled via Register 0x01, Bit 5.  
The problem becomes more pronounced in multiboard  
synchronization where clock signals (that is, DACCLK,  
SYNC_OUT, and DCO) are distributed over a back plane to  
multiple PCBs. Data alignment among the various data sources  
is required when driven by phase aligned DCO signals that are  
a buffered version of the masters DCO. However, these data  
sources (FPGAs) also have process, supply voltage, and  
temperature sensitivities (PVTs) that can cause misalignment  
among their respective DCI outputs.  
Synchronization Limitations  
Ensuring consistent synchronization over production lots in  
systems containing two or more AD9739s becomes increasingly  
more challenging at the higher update rates because the timing  
offset between adjacent phases of the div-by-4 output clock is  
equal to 1/fDAC . For example, a DAC update of 2 GSPS corresponds  
to a 500 ps period. If the SYNC_IN signal of an ideal master  
device is positioned in the center of its div-by-4 0o and 90o phase  
outputs, only 250 ps of timing margin exists for the slave  
devices. This ideal margin is actually reduced by quadrature  
phase errors in the div-by-4 circuit of the master as well as its  
ability to position the SYNC_IN exactly in the center of the 0°  
and 90° output phases.  
Adding to this dilemma is that it also possible for the data  
receiver controller of different AD9739s to converge on different  
delay settings due to PVT variations of the delay line (even if  
DCI inputs are exactly aligned). This can result in a four sample  
pipeline mismatch between devices if the difference in absolute  
delays exceeds a period of 4/fDAC. Recall that the controller searches  
up/down for its first valid edge from its initial start value (that is,  
DCI_DEL and SMP_DEL). While the initial start values between  
devices should be made the same, different absolute time delays  
due to PVT can cause devices to converge on different edges of  
DCI above or below this initial start value. As a result, confirm  
that DCI_DEL values between multiple devices are matched  
sufficiently such that the absolute differences between the  
readback DCI_DEL values do not exceed a data period (that is,  
4/fDAC). If the difference exceeds a data period, modify the  
DCI_DEL (and SMP_DEL) setting of the slave device so that its  
start point is roughly ½ the difference between the master and  
slave readback values.  
The timing margin is further eroded by the following sources:  
Master-to-slave device(s) mismatch in the propagation delays  
in the mu delay clock path and SYNC_IN. Note that these  
mismatches can be up to 100 ps between devices that are at  
opposite extremes of the process corners.  
Quadrature phase errors in the div-by-4 outputs of the slave.  
Rev. B | Page 37 of 48  
AD9739  
Data Sheet  
ANALOG INTERFACE CONSIDERATIONS  
ANALOG MODES OF OPERATION  
INPUT  
DATA  
D
D
D
D
D
D
D
D
D
D
10  
1
2
3
4
5
6
7
8
9
DACCLK_x  
The AD9739 uses the quad-switch architecture shown in Figure 54.  
The quad-switch architecture masks the code-dependent glitches  
that occur in a conventional two-switch DAC. Figure 55 compares  
the waveforms for a conventional DAC and the quad-switch  
DAC. In the two-switch architecture, a code-dependent glitch  
occurs each time the DAC switches to a different state (that is,  
D1 to D2). This code-dependent glitching causes an increased  
amount of distortion in the DAC. In a quad-switch architecture  
(no matter what the codes are), there are always two switches  
transitioning at each half clock cycle, thus eliminating the code-  
dependent glitches. However, a constant glitch occurs at 2 ×  
DACCLK because half of the internal switches change state on  
the rising DACCLK edge, while the other half change state on  
the falling DACCLK edge.  
D
–D  
8
3
D
D
–D  
–D  
9
2
4
7
D
D
–D  
–D  
10  
1
5
6
FOUR-SWITCH  
DAC OUTPUT  
t
(
fS MIX MODE)  
D
–D  
5
D
10  
–D  
6
1
–D  
–D  
D
D
9
2
4
7
–D  
D
8
3
FOUR-SWITCH  
DAC OUTPUT  
(RETURN TO  
ZERO MODE)  
D
D
D
D
D
10  
t
6
7
8
9
D
D
D
D
D
5
1
2
3
4
Figure 56. Mix-Mode and RZ DAC Waveforms  
Figure 56 shows the DAC waveforms for both the mix mode  
and the RZ mode. Note that the disadvantage of the RZ mode  
is the 6 dB loss of power to the load because the DAC is only  
functioning for ½ the DAC update period. This ability to change  
modes provides the user the flexibility to place a carrier anywhere  
in the first three Nyquist zones, depending on the operating  
mode selected. Switching between the analog modes reshapes  
the sinc roll-off inherent at the DAC output. The maximum  
amplitude in all three Nyquist zones is impacted by this sinc  
roll-off, depending on where the carrier is placed (see Figure 57).  
As a practical matter, the usable bandwidth in the third Nyquist  
zone becomes limited at higher DAC clock rates (that is, >2 GSPS)  
when the output bandwidth of DAC core and the interface  
network (that is, balun) contributes to additional roll-off.  
V
DD  
DACCLK_x  
CLK  
V
V
V
V
1
2
3
4
G
G
G
V
1
V
2
V
3
V 4  
G
LATCHES  
G
G
G
DBx[13:0]  
G
IOUTP  
IOUTN  
Figure 54. AD9739 Quad-Switch Architecture  
INPUT  
DATA  
D
D
D
D
D
D
D
D
D
D
1
2
3
4
5
6
7
8
9
10  
DACCLK_x  
FIRST  
NYQUIST ZONE  
SECOND  
NYQUIST ZONE  
THIRD  
NYQUIST ZONE  
D
D
D
D
D
0
–5  
t
t
1
2
3
4
5
TWO-SWITCH  
DAC OUTPUT  
MIX MODE  
D
D
D
D
D
6
7
8
9
10  
RZ MODE  
–10  
–15  
–20  
–25  
–30  
–35  
FOUR-SWITCH  
DAC OUTPUT  
(NORMAL MODE)  
D
D
D
D
D
10  
6
7
8
9
D
D
D
D
D
5
1
2
3
4
NORMAL  
MODE  
Figure 55. Two-Switch and Quad-Switch DAC Waveforms  
Another attribute of the quad-switch architecture is that it also  
enables the DAC core to operate in one of the following three  
modes: normal mode, mix mode, and return-to-zero (RZ) mode.  
The mode is selected via SPI Register 0x08, Bits[1:0] with  
normal mode being the default value. In the mix mode, the  
output is effectively chopped at the DAC sample rate. This has  
the effect of reducing the power of the fundamental signal while  
increasing the power of the images centered around the DAC  
sample rate, thus improving the output power of these images.  
The RZ mode is similar to the analog mix mode, except that the  
intermediate data samples are replaced with midscale values.  
0FS  
0.25FS  
0.50FS  
0.75FS  
1.00FS  
1.25FS  
1.50FS  
FREQUENCY (Hz)  
Figure 57. Sinc Roll-Off for Each Analog Operating Mode  
Rev. B | Page 38 of 48  
 
 
 
 
 
Data Sheet  
AD9739  
Each single-ended output can provide a squared-up output level  
that can be varied from −4 dBm to +5 dBm allowing for >2 V p-p  
output differential swings. The ADF4350 also includes an  
additional CML buffer that can be used to drive another  
AD9739 device.  
CLOCK INPUT CONSIDERATIONS  
The quality of the clock source and its drive strength are  
important considerations in maintaining the specified ac  
performance. The phase noise and spur characteristics of the  
clock source should be selected to meet the target application  
requirements. Phase noise and spurs at a given frequency offset  
on the clock source are directly translated to the output signal. It  
can be shown that the phase noise characteristics of a reconstructed  
output sine wave are related to the clock source by 20 × log10  
(fOUT/fCLK) when the DAC clock path contribution, along with  
thermal and quantization effects, are negligible.  
VDDC  
4-BIT PMOS  
IOUT ARRAY  
CLKx_OFFSET  
DIR_x = 0  
DACCLK_P  
ESD  
DACCLK_N  
CLKx_OFFSET  
DIR_x = 0  
The AD9739 clock receiver provides optimum jitter performance  
when driven by a fast slew rate originating from the LVPECL or  
CML output drivers. For a low jitter sinusoidal clock source, the  
ADCLK914 can be used to square-up the signal and provide a  
CML input signal for the AD9739 clock receiver. Note that all  
specifications and characterization presented in the data sheet  
are with the ADCLK914 driven by a high quality RF signal  
generator with the clock receiver biased at a 800 mV level. A  
dc blocking capacitor is used between the clock driver output  
and clock receiver input to allow for different dc bias levels.  
To minimize signal loss for high clock rates, a high quality, dc  
blocking RF capacitor is recommended.  
4-BIT NMOS  
IOUT ARRAY  
VSSC  
Figure 58. Clock Input and Common-Mode Control  
The AD9739 clock receiver features the ability to independently  
adjust the common-mode level of its inputs over a span of  
100 mV centered about its midsupply point (that is, VDDC/2)  
as well as an offset for hysteresis purposes. Figure 58 shows the  
equivalent input circuit of one of the inputs. ESD diodes are not  
shown for clarity purposes. It has been found through  
characterization that the optimum setting is for both inputs to  
be biased at approximately 0.8 V. This can be achieved by writing a  
0x0F (corresponding to a −15) setting to both cross controller  
registers (that is, Register 0x22 and Register 0x23).  
Figure 60 shows a clock source based on the ADF4350 low phase  
noise/jitter PLL. The ADF4350 can provide output frequencies  
from 140 MHz up to 4.4 GHz with jitter as low as 0.5 ps rms.  
V
V
V
CC  
REF  
ADCLK914  
AD9739  
T
5050Ω  
1nF  
50Ω  
50Ω  
10nF  
10nF  
D
D
50Ω  
Q
Q
DACCLK_P  
DACCLK_N  
100Ω  
1nF  
50Ω  
V
EE  
Figure 59. ADCLK914 Interface to the AD9739 CLK Input  
AD9739  
3.9nH  
V
VCO  
ADF4350  
1nF  
1nF  
RF  
RF  
A+  
A–  
OUT  
DACCLK_P  
DACCLK_N  
N
DIV-BY-2  
N = 0 – 4  
PLL  
100  
VCO  
FREF  
OUT  
1.8V p-p  
RF  
RF  
A+  
A–  
OUT  
OUT  
Figure 60. ADF4350 Interface to the AD9739 CLK Input  
Rev. B | Page 39 of 48  
 
 
 
AD9739  
Data Sheet  
1.10  
1.05  
1.00  
0.95  
0.90  
0.85  
0.80  
0.75  
0.70  
The following equation relates IOUTFS to the FSC[9:0] register,  
which can be set from 0 to 1023:  
CLKP  
CLKN  
I
OUTFS = 22.6 × FSC[9:0]/1000 + 8.7  
(1)  
Note that a default value of 0x200 generates 20 mA full scale,  
which is used for most of the characterization presented in this  
data sheet (unless noted otherwise).  
ANALOG OUTPUTS  
Equivalent DAC Output and Transfer Function  
The AD9739 provides complementary current outputs, IOUTP  
and IOUTN, that source current into an external ground reference  
load. Figure 63 shows an equivalent output circuit for the DAC.  
Note that, compared to most current output DACs of this type,  
the AD9739 outputs exhibit a slight offset current (that is,  
–15 –13 –11 –9 –7 –5 –3 –1  
1
3
5
7
9
11 13 15  
OFFSET CODE  
Figure 61. Common-Mode Voltage with Respect to  
CLKP_OFFSET/CLKN_OFFSET and DIR_P/DIR_N  
I
OUTFS/16), and the peak differential ac current is slightly below  
I
OUTFS/2 (that is, 15/32 × IOUTFS).  
VOLTAGE REFERENCE  
I
= 8.6 – 31.2mA  
OUTFS  
The AD9739 output current is set by a combination of digital  
control bits and the I120 reference current, as shown in Figure 62.  
17/32 × I  
OUTFS  
AD9739  
I
=
PEAK  
FSC[9:0]  
AC  
2.2pF  
15/32 × I  
70  
V
OUTFS  
BG  
DAC  
1.2V  
VREF  
17/32 × I  
OUTFS  
I120  
CURRENT  
SCALING  
+
1nF  
IFULL-SCALE  
10k  
Figure 63. Equivalent DAC Output Circuit  
I120  
AGND  
As shown in Figure 63, the DAC output can be modeled as a pair of  
dc current sources that source a current of 17/32 × IOUTFS to each  
output. A differential ac current source, IPEAK, is used to model  
the signal-dependent nature of the DAC output. The polarity  
and signal dependency of this ac current source are related to  
the digital code by the following equations:  
Figure 62. Voltage Reference Circuit  
The reference current is obtained by forcing the band gap voltage  
across an external 10 kꢀ resistor from I120 (Pin B14) to ground.  
The 1.2 V nominal band gap voltage (VREF) generates a 120 μA  
reference current in the 10 kꢀ resistor. Note the following  
constraints when configuring the voltage reference circuit:  
F(Code) = (DACCODE − 8192)/8192  
−1 ≤ F(Code) < 1  
(2)  
(3)  
Both the 10 kꢀ resistor and 1 nF bypass capacitor are required  
for proper operation.  
Adjusting the output full-scale current, IOUTFS, of the DAC  
from its default setting of 20 mA should be performed  
digitally.  
The AD9739 is not a multiplying DAC. Modulating the  
reference current, I120, with an ac signal is not supported.  
The band gap voltage appearing at VREF (Pin C14) must  
be buffered for use with external circuitry because its  
output impedance is approximately 5 kꢀ.  
where DACCODE = 0 to 16,383 (decimal).  
Because IPEAK can swing (15/32) × IOUTFS, the output currents  
measured at IOUTP and IOUTN can span from IOUTFS/16 to  
I
OUTFS. However, because the ac signal-dependent current  
component is complementary, the sum of the two outputs is  
always constant (that is, IOUTP + IOUTN = (34/32) × IOUTFS).  
The code-dependent current measured at the IOUTP (and  
IOUTN) output is as follows:  
An external reference can be used to overdrive the internal  
reference by connecting it to VREF (Pin C14).  
IOUTP = 17/32 × IOUTFS + 15/32 × IOUTFS × F(Code)  
IOUTN = 17/32 × IOUTFS − 15/32 × IOUTFS × F(Code)  
(4)  
(5)  
I
OUTFS can be adjusted digitally over 8.7 mA to 31.7 mA by using  
FSC[9:0] (Register 0x06 and Register 0x07).  
Rev. B | Page 4± of 48  
 
 
 
Data Sheet  
AD9739  
Figure 64 shows the IOUTP vs. DACCODE transfer function  
If the AD9739 is programmed for IOUTFS = 20 mA, its peak ac  
when IOUTFS is set to 19.65 mA.  
current is 9.375 mA and its peak power delivered to the equivalent  
load is 2.2 mW (that is, P = I2R). Because the source and load  
resistance seen by the 1:1 balun are equal, this power is shared  
equally; therefore, the output load receives 1.1 mW or 0.4 dBm.  
20  
18  
16  
14  
12  
10  
8
To calculate the rms power delivered to the load, the following  
must be considered:  
Peak-to-rms of the digital waveform  
Any digital backoff from digital full scale  
The DAC’s sinc response and nonideal losses in external  
network  
6
4
For example, a reconstructed sine wave with no digital backoff  
ideally measures −2.6 dBm because it has a peak-to-rms ratio of  
3 dB. If a typical balun loss of 0.4 dBm is included, −3 dBm of  
actual power can be expected in the region where the sinc response  
of the DAC has negligible influence. Increasing the output power is  
best accomplished by increasing IOUTFS, although any degradation in  
linearity performance must be considered acceptable for the  
target application.  
2
0
0
4096  
8192  
12,288  
16,384  
DAC CODE  
Figure 64. Gain Curve for FSC[9:0] = 512, DAC Offset = 1.228 mA  
Peak DAC Output Power Capability  
The maximum peak power capability of a differential current  
output DAC is dependent on its peak differential ac current, IPEAK  
and the equivalent load resistance it sees. Because the AD9739  
includes a differential 70 Ω resistance, it is best to use a doubly  
terminated external output network similar to what is shown in  
Figure 65. In this case, the equivalent load seen by the ac current  
source of the DAC is 25 Ω.  
,
R
SOURCE  
= 50  
I
= 8.6 – 31.2mA  
OUTFS  
LOSSLESS  
BALUN  
1:1  
I
=
R
= 50Ω  
PEAK  
LOAD  
AC  
70Ω  
180Ω  
15/32 × I  
OUTFS  
Figure 65. Equivalent Circuit for Determining Maximum Peak Power to a 50 Ω Load  
Rev. B | Page 41 of 48  
 
 
AD9739  
Data Sheet  
Figure 68 shows an interface that can be considered when  
Output Stage Configuration  
interfacing the DAC output to a self-biased differential gain  
block. The inductors shown serve as RF chokes (L) that provide  
the dc bias path to analog ground. The value of the inductor,  
along with the dc blocking capacitors (C), determines the lower  
cutoff frequency of the composite pass-band response. An RF  
balun should also be considered before the RF differential gain  
stage and any filtering to ensure symmetrical common-mode  
impedance seen by the DAC output while suppressing any  
common-mode noise, harmonics, and clock spurs prior to  
amplification.  
The AD9739 is intended to serve high dynamic range applications  
that require wide signal reconstruction bandwidth (that is,  
DOCSIS CMTS) and/or high IF/RF signal generation. Optimum ac  
performance can only be realized if the DAC output is configured  
for differential (that is, balanced) operation with its output  
common-mode voltage biased to analog ground. The output  
network used to interface to the DAC should provide a near 0 Ω  
dc bias path to analog ground. Any imbalance in the output  
impedance between the IOUTP and IOUTN pins results in  
asymmetrical signal swings that degrade the distortion  
performance (mostly even order) and noise performance.  
Component selection and layout are critical in realizing the  
performance potential of the AD9739.  
OPTIONAL BALUN AND FILTER  
IOUTP  
C
90  
L
RF DIFF  
AMP  
C
70Ω  
LPF  
90Ω  
®
L
MINI-CIRCUITS  
TC1-33-75G+  
IOUTN  
IOUTP  
90  
90Ω  
Figure 68. Interfacing the DAC Output to the Self-Biased Differential Gain Stage  
70Ω  
For applications operating the AD9739 in mix mode with output  
frequencies extending beyond 2.2 GHz, the circuits shown in  
Figure 69 should be considered. The circuit in Figure 69 uses a  
wideband balun with a configuration similar to the one shown  
in Figure 68 to provide a dc bias path for the DAC outputs. The  
circuit in Figure 70 takes advantage of ceramic chip baluns to  
provide a dc bias path for the DAC outputs while providing  
excellent amplitude/phase balance over a narrower RF band.  
These low cost, low insertion loss baluns are available for  
different popular RF bands and provide excellent amplitude/  
phase balance over their specified frequency range.  
IOUTN  
Figure 66. Recommended Balun for Wideband Applications with Upper  
Bandwidths of up to 2.2 GHz  
Most applications requiring balanced-to-unbalanced conversion can  
take advantage of the Ruthroff 1:1 balun configuration shown in  
Figure 66. This configuration provides excellent amplitude/phase  
balance over a wide frequency range while providing a 0 Ω dc bias  
path to each DAC output. Also, its design provides exceptional  
bandwidth and can be considered for applications requiring  
signal reconstruction of up to 2.2 GHz. The characterization plots  
shown in this data sheet are based on the AD9739 evaluation  
board, which uses this configuration. Figure 67 compares the  
measured frequency response for normal and mix mode using  
the AD9739 evaluation board vs. the ideal frequency response.  
MINI-CIRCUITS  
TC1-1-462M  
C
IOUTP  
90  
90Ω  
L
L
70Ω  
IOUTN  
C
0
IDEAL BASEBAND MODE  
Figure 69. Recommended Mix Mode Configuration Offering Extended RF  
Bandwidth Using a TC1-1-43A+ Balun  
–3  
BASEBAND  
TC1-33-75G  
–6  
–9  
MURATA  
JOHANSON TECHNOLOGY  
CHIP BALUNS  
MIX MODE  
TC1-33-75G  
IOUTP  
–12  
–15  
–18  
–21  
–24  
–27  
–30  
–33  
–36  
IDEAL MIX MODE  
70  
180Ω  
IOUTN  
Figure 70. Lowest Cost and Size Configuration for Narrow RF Band Operation  
0
500  
1000  
1500  
2000  
2500  
3000  
3500  
FREQUENCY (MHz)  
Figure 67. Measured vs. Ideal Frequency Response for Normal (Baseband)  
and Mix Mode Operation Using a TC1-33-75G Transformer on the AD9739  
Evaluation Board  
Rev. B | Page 42 of 48  
 
 
 
 
 
Data Sheet  
AD9739  
3. Images appear as replicas of the original signal, therefore,  
can be easier to identify. In the case of the AD9739, internal  
modulation of the sampling clock at intervals related to  
NONIDEAL SPECTRAL ARTIFACTS  
The AD9739 output spectrum contains spectral artifacts that  
are not part of the original digital input waveform. These non-  
ideal artifacts included harmonics (including alias harmonics),  
images, and clock spurs. Figure 71 shows a spectral plot of the  
AD9739 within the first Nyquist zone (that is, dc to fDAC/2)  
reconstructing a 650 MHz, 0 dBFS sine wave at 2.4 GSPS. Besides  
the desired fundamental tone at the −7.8 dBm level, the spectrum  
also reveals these nonideal artifacts that also appear as spurs  
above the measurement noise floor. Because these nonideal  
artifacts are also evident in the second and third Nyquist zones  
during mix mode operation, the effects of these artifacts should  
also be considered when selecting the DAC clock rate for a  
target RF band.  
f
DAC/4 generate image pairs at ¼ × fDAC, ½ × fDAC, and ¾ × fDAC  
Both upper and lower sideband images associated with ¼ ×  
DAC fall within the first Nyquist zone, while only the lower  
.
f
image of ½ × fDAC and ¾ × fDAC fall back. Note that the lower  
images appear frequency inverted. The difference in dBc  
between the fundamental and various images remains  
mostly signal independent because the mechanism causing  
these images is related to corruption of the sampling clock.  
4. The magnitude of these images for a given device is dependent  
on several factors including DAC clock rate, output frequency,  
mu controller phase setting, and div-by-4 clock divider  
phase (Register 0x14, bit [7:6]. Table 30 shows how the  
magnitude of these images vary as the phase is varied for  
the case represented in Figure 71. Because the phase varies  
at power up, the image magnitude varies making it difficult  
to compensate digitally through a one-time factory  
0
FUND AT  
–10  
–20  
–30  
–40  
–50  
–60  
–70  
–80  
–90  
–100  
–7.6dBm  
calibration procedure. Also, the image magnitude can vary  
a few decibels over temperature and between devices due  
to process dependencies. (Note that the AD9739A is a  
viable option if factory calibration is considered acceptable  
for nonmultichip synchronization applications operating  
with clock rates in the 1.6 GSPS to 2.5 GSPS range).  
fDAC/2 –  
fOUT  
3/4 × fDAC/4 –  
fOUT  
fDAC/4  
HD3  
fDAC/4 –  
fOUT  
HD2  
HD5  
HD6  
HD9  
HD4  
Table 30. Image Magnitude vs. Phase (PHZ) Setting  
Image location  
PHZ0 PHZ1  
−7±.2 −71.4  
−8±.2 −71.3  
−69.9 −72.5  
PHZ2  
−72.2  
−69.9  
−73.4  
PHZ3  
−77.1  
−74.9  
−73.7  
0
200  
400  
600  
800  
1000  
1200  
FREQUENCY (MHz)  
fDAC/4 − fOUT  
Figure 71. Spectral Plot  
fDAC/2 − fOUT  
¾ × fDAC − fOUT  
Note the following important observations pertaining to these  
nonideal spectral artifacts:  
5. A clock spur appears at fDAC/4 and integer multiples of this  
frequency. Similar to images, the spur magnitude is also  
dependent on the same factors that cause variations in  
image levels. However, unlike images and harmonics, clock  
spurs always appear as discrete spurs, albeit their magnitude  
shows a slight dependency on the digital waveform and  
output frequency. Note that the clock spur appearing at fDAC/4  
can also be factory calibrated.  
1. A full-scale sine wave (that is, single-tone) typically represents  
the worst-case condition because it has a peak-to-rms ratio of  
3 dB and is unmodulated. Harmonics and aliased harmonics  
of a sine wave are easy to identify because they also appear  
as discrete spurs. Significant characterization of a high  
speed DAC is performed using single (or multitone)  
signals for this reason.  
2. Modulated signals (that is, AM, PM, or FM) do not appear as  
spurs but rather as signals whose power spectral density is  
spread over a defined bandwidth determined by the  
modulation parameters of the signals. Any harmonics from  
the DAC spread over a wider bandwidth determined by the  
order of the harmonic and bandwidth of the modulated signal.  
For this reason, harmonics often appear as slight bumps in  
the measurement noise floor and can be difficult to discern.  
6. A large clock spur also appears at 2 × fDAC in either normal  
or mix mode operation. This clock spur is due to the quad  
switch DAC architecture causing switching events to occur  
on both edges of fDAC  
.
Rev. B | Page 43 of 48  
 
 
 
AD9739  
Data Sheet  
LAB EVALUATION OF THE AD9739  
POWER DISSIPATION AND SUPPLY DOMAINS  
Figure 72 shows a recommended lab setup that was used to  
characterize the performance of the AD9739. The DPG2 is a  
dual port LVDS/CMOS data pattern generator available from  
Analog Devices, Inc., with an up to 1.25 GSPS data rate. The  
DPG2 directly interfaces to the AD9739 evaluation board via  
Tyco Z-PACK HM-Zd connectors. A low phase noise/jitter RF  
source, such as an R&S SMA100A signal generator, is used for  
the DAC clock. A 5 V power supply is used to power up the  
AD9739 evaluation board, and SMA cabling is used to interface  
to the supply, clock source, and spectrum analyzer. A USB 2.0  
interface to a host PC is used to communicate to both the AD9739  
evaluation board and the DPG2.  
The power dissipation of the AD9739 is dependent on the DAC  
clock rate as shown in Figure 73 and Figure 74. The current  
consumption from the 3.3 V supply remains relatively constant  
because it is used for biasing the DAC core (that is, VDDA) and  
differential input receivers (that is, VDD33). However, the current  
consumption from the 1.8 V supply is clock rate dependent and  
increases linearly with frequency because this supply is used by  
the digital path (that is, VDD) as well as the clock distribution  
circuitry (that is, VDDC).  
Treat the VDDC supply as an analog supply because the clock  
distribution circuitry has poor power supply rejection; therefore,  
noise on this supply can induce clock jitter. To ensure low noise  
on this sensitive supply, use a separate 1.8 V regulator powered  
from the 3.3 V analog supply rail that is also used to power  
VDDA. This supply rail can also be used to power-up VDD33  
via an LC filter network. The digital 1.8 V supply, VDD, can be  
supplied via a well-filtered switching regulator.  
1.2  
A high dynamic range spectrum analyzer is required to evaluate  
the AD9739 reconstructed waveforms ac performance. This is  
especially the case when measuring ACLR performance for high  
dynamic range applications, such as multicarrier DOCSIS CMTS  
applications. Harmonic, SFDR, and IMD measurements pertaining  
to unmodulated carriers can benefit by using a sufficiently high  
RF attenuation setting because these artifacts are easy to identify  
above the spectrum analyzer noise floor. However, reconstructed  
waveforms having modulated carrier(s) often benefit from the  
use of a high dynamic range RF amplifier and/or passive filters  
to measure close-in and wideband ACLR performance when  
using spectrum analyzers of limited dynamic range.  
1.1  
1.0  
TOTAL  
0.9  
0.8  
0.7  
0.6  
0.5  
VDD  
VDDC  
USB 2.0  
LAB  
PC  
0.4  
0.3  
ADI PATTERN GENERATOR  
DPG2  
0.2  
LVDS  
VDDA  
DATA  
0.1  
AND DCI  
DCO  
VDD33  
0
0
250 500 750 1000 1250 1500 1750 2000 2250 2500  
fDAC (MHz)  
GPIB  
1.6GHz TO  
2.5GHz  
Figure 73. Power Consumption vs. fDAC @ 25°C  
POWER  
SUPPLY  
+5V  
AD9739  
EVAL. BOARD  
3dBm  
RHODE AND  
SCHWARTZ  
SMA 100A  
360  
330  
300  
270  
240  
210  
180  
150  
120  
90  
10 MHz  
REFIN  
AGILENT PSA  
E4440A  
10 MHz  
REOUT  
Figure 72. Lab Test Setup Used to Characterize the AD9739  
I_VDD  
I_VDDC  
60  
I_VDDA  
30  
I_VDD33  
0
0
250 500 750 1000 1250 1500 1750 2000 2250 2500  
fDAC (MHz)  
Figure 74. Current Consumption vs. fDAC @ 25°C  
Rev. B | Page 44 of 48  
 
 
 
 
Data Sheet  
AD9739  
The mu controller must be first enabled (and in track mode)  
before the data receiver controller is enabled because the  
DCO output signal is derived from this circuitry.  
A wait period is related to fDATA periods.  
Limit the number of attempts to lock the controllers to  
three; locks typically occur on the first attempt.  
Hardware or software interrupts can be used to monitor  
the status of the controllers.  
RECOMMENDED START-UP SEQUENCE  
Upon power-up of the AD9739, a host processor is required  
to initialize and configure the AD9739 via its SPI port. Figure 75  
shows a flowchart of the sequential steps required, while Table 31  
and Table 32 provides more detail on the SPI register write/read  
operations required to implement the flowchart steps. Note the  
following:  
A software reset is optional because the AD9739 has both  
an internal POR circuit and a RESET pin.  
The SYNC controller is optional because it is only required  
to synchronize two or more devices. If synchronization is  
required, validate that DCI_DEL values between devices  
are sufficiently matched.  
CONFIGURE  
SPI PORT  
NO  
NO  
COMPARE  
DCI_DEL  
VALUES  
CONFIGURE  
SYNC  
CONT.  
CONFIGURE  
Rx DATA  
CONT.  
NO  
CONFIGURE  
MU CONT.  
SYNC.  
ONLY  
SOFTWARE  
RESET  
WAIT A  
FEW 100µs  
WAIT A  
FEW 100µs  
RECONFIGURE  
TxDAC FROM  
DEFAULT SETTING  
WAIT A  
FEW 100µs  
SET CLK  
INPUT CMV  
Rx  
OPTIONAL  
MU CONT.  
LOCKED?  
SYNC CONT.  
VALID?  
DATA CONT.  
LOCKED?  
YES  
YES  
YES  
Figure 75. Flowchart for Initialization and Configuration of the AD9739  
Rev. B | Page 45 of 48  
 
 
AD9739  
Data Sheet  
Table 31. Recommended SPI Initialization with SYNC Controller Disabled  
Step  
Address (Hex)  
Write Value  
Comments  
1
±x±±  
±x±±  
Configure for the 4-wire SPI mode with MSB. Note that Bits[7:5] must be mirrored onto  
Bits[2:±] because the MSB/LSB format can be unknown at power-up.  
2
±x±±  
±x2±  
±x±±  
±x±F  
±x±F  
±x3±  
±x8±  
±x44  
±x6C  
±xCB  
±x±2  
±x±3  
Software reset to default SPI values.  
3
±x±±  
Clear the reset bit.  
4
±x22  
Set the common-mode voltage of DACCLK_P and DACCLK_N inputs.  
5
±x23  
6
±x24  
Configure the mu controller. Refer to Table 28 for recommended target mu slope and  
phase settings vs. clock rate.  
7
±x25  
8
±x27  
9
±x28  
1±  
11  
12  
13  
14  
±x29  
±x26  
±x26  
Enable the mu controller search and track mode.  
Not applicable  
±x2A  
Not applicable Wait for 16± K × 1/fDATA cycles.  
Read back Register ±x2A and confirm that it is equal to ±x±1 to ensure that the DLL loop  
is locked. If it is not locked, proceed to Step 1± and repeat. Limit attempts to three  
before breaking out of the loop and reporting a mu lock failure.  
15  
16  
17  
18  
19  
2±  
21  
Not applicable  
±x13  
Not applicable Ensure that the AD9739 is fed with DCI clock input from the data source.  
±x72  
±x±±  
±x±2  
±x±3  
Set FINE_DEL_SKEW to 2.  
±x1±  
Disable the data Rx controller before enabling it.  
Enable the data Rx controller for loop and IRQ.  
Enable the data Rx controller for search and track mode.  
±x1±  
±x1±  
Not applicable  
±x21  
Not applicable Wait for 135 K × 1/fDATA cycles.  
Read back Register ±x21 and confirm that it is equal to ±x±9 to ensure that the DLL loop  
is locked and tracking. If it is not locked and tracking, advance the CLKDIVPH[1:±] phase  
in Register ±x14, Bit[7:6] before proceeding to Step 17 to repeat attempt. Limit attempts  
to three before breaking out of the loop and reporting an Rx data lock failure.  
22  
23  
±x±6, ±x±7  
±x±8  
±x±±, ±x±2  
±x±±  
Optional: modify the TxDAC IOUTFS setting (the default is 2± mA).  
Optional: modify the TxDAC operation mode (the default is normal mode).  
Rev. B | Page 46 of 48  
 
Data Sheet  
AD9739  
Table 32. Recommended SPI Initialization with SYNC Controller Enabled  
Step  
Address (Hex)  
Write Value  
Comments  
1
±x±±  
±x±±  
Configure for the 4-wire SPI mode with MSB. Note that Bits[7:5] must be mirrored onto  
Bits[2:±] because the MSB/LSB format can be unknown at power-up.  
2
±x±±  
±x2±  
±x±±  
±x±F  
±x±F  
±x3±  
±x8±  
±x44  
±x6C  
±xCB  
±x±2  
±x±3  
Software reset to default SPI values.  
3
±x±±  
Clear the reset bit.  
4
±x22  
Set the common-mode voltage of DACCLK_P and DACCLK_N inputs.  
5
±x23  
6
±x24  
Configure the mu controller. Refer to Table 28 for recommended target Mu slope and  
phase settings vs. clock rate.  
7
±x25  
8
±x27  
9
±x28  
1±  
11  
12  
13  
14  
±x29  
±x26  
±x26  
Enable the mu controller search and track mode.  
Not applicable  
±x2A  
Not applicable Wait for 16± K × 1/fDATA cycles.  
Read back Register ±x2A and confirm that it is equal to ±x±1 to ensure that the DLL loop  
is locked. If it is not locked, proceed to Step 1± and repeat. Limit attempts to three  
before breaking out of the loop and reporting a mu lock failure.  
15  
16  
17  
±x15  
±x1±  
±x1±  
±x42  
Configure sync controller.  
Disable sync controller before enabling it.  
Enable sync controller for loop and IRQ.  
±x6± = master mode.  
±x±±  
±x6± or ±x4±  
±x4± = slave mode.  
18  
±x1±  
±x7± or ±x5±  
Enable sync controller:  
±x7± = master mode.  
±x5± = slave mode.  
19  
2±  
Not applicable  
±x21  
Not applicable Wait for 16± K × 1/fDATA for DLL to lock.  
Read back Register ±x21 to confirm proper operation:  
±x9± = master mode.  
±x±± = slave mode.  
If not, proceed to Step 15 and repeat. Limit to three attempts before breaking out of  
loop and reporting sync lock failure.  
21  
±x±D  
Read back Register ±x±D and confirm Bits[5:4] = 1±. If not, proceed to Step 2 and repeat.  
Limit to three attempts before breaking out of loop and reporting sync lock failure.  
22  
23  
24  
25  
26  
27  
28  
Not applicable  
±x13  
Not applicable Ensure that the AD9739 is fed with DCI clock input from the data source.  
±x72  
±x±±  
±x±2  
±x±3  
Set FINE_DEL_SKEW to 2.  
±x1±  
Disable the data Rx controller before enabling it.  
Enable the data Rx controller for loop and IRQ.  
Enable the data Rx controller for search and track mode.  
Wait for 135 K × 1/fDATA cycles.  
±x1±  
±x1±  
±x21  
Read back Register ±x21 and confirm that it is equal to ±x±9 to ensure that the DLL loop  
is locked and tracking. If it is not locked and tracking, proceed to Step 16 and repeat.  
Limit attempts to three before breaking out of the loop and reporting an Rx data lock  
failure.  
29  
Not applicable  
Not applicable Readback DCI_DEL value in Register ±x13 and Register ±x14 for master and. If slave  
devices are not within 4± codes of each other, re-specify target DCI_DEL value to be  
average between master and readback DCI_DEL value.  
3±  
31  
±x±6, ±x±7  
±x±8  
±x±±, ±x±2  
±x±±  
Optional: modify the TxDAC IOUTFS setting (the default is 2± mA).  
Optional: modify the TxDAC operation mode (the default is normal mode).  
Rev. B | Page 47 of 48  
 
AD9739  
Data Sheet  
OUTLINE DIMENSIONS  
12.10  
12.00 SQ  
11.90  
A1 BALL  
CORNER  
A1 BALL  
CORNER  
13 11  
14 12 10  
9
7
5
3
1
8
6
4
2
A
B
C
D
E
F
10.40  
BSC SQ  
G
H
J
K
L
0.80  
BSC  
M
N
P
BOTTOM VIEW  
DETAIL A  
TOP VIEW  
1.00 MAX  
0.85 MIN  
DETAIL A  
0.43 MAX  
1.40 MAX  
0.25 MIN  
0.55  
0.50  
0.45  
COPLANARITY  
0.12  
SEATING  
PLANE  
BALL DIAMETER  
COMPLIANT WITH JEDEC STANDARDS MO-275-GGAA-1.  
Figure 76. 160-Ball Chip Scale Package Ball Grid Array [CSP_BGA]  
(BC-160-1)  
Dimensions shown in millimeters  
ORDERING GUIDE  
Model1  
Temperature Range  
Package Description  
Package Option  
BC-16±-1  
BC-16±-1  
BC-16±-1  
BC-16±-1  
AD9739BBCZ  
AD9739BBCZRL  
AD9739BBC  
AD9739BBCRL  
AD9739-R2-EBZ  
−4±°C to +85°C  
−4±°C to +85°C  
−4±°C to +85°C  
−4±°C to +85°C  
16±-Ball Chip Scale Package Ball Grid Array [CSP_BGA]  
16±-Ball Chip Scale Package Ball Grid Array [CSP_BGA]  
16±-Ball Chip Scale Package Ball Grid Array [CSP_BGA]  
16±-Ball Chip Scale Package Ball Grid Array [CSP_BGA]  
Evaluation Board  
1 Z = RoHS Compliant Part.  
©2009–2012 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D07851-0-1/12(B)  
Rev. B | Page 48 of 48  
 
 

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