Analog Devices AD9912 User Manual
1 gsps direct digital synthesizer with 14-bit dac, Ad9912, Features
1 GSPS Direct Digital
Synthesizer with 14-Bit DAC
AD9912
Rev. D
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rights of third parties that may result from its use. Specifications subject to change without notice. No
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Tel: 781.329.4700
Fax: 781.461.3113 ©2007–2009 Analog Devices, Inc. All rights reserved.
FEATURES
1 GSPS internal clock speed (up to 400 MHz output directly)
Integrated 1 GSPS 14-bit DAC
48-bit frequency tuning word with 4 µHz resolution
Differential HSTL comparator
Flexible system clock input accepts either crystal or external
reference clock
On-chip low noise PLL REFCLK multiplier
2 SpurKiller channels
Low jitter clock doubler for frequencies up to 750 MHz
Single-ended CMOS comparator; frequencies of <150 MHz
Programmable output divider for CMOS output
Serial I/O control
Excellent dynamic performance
Software controlled power-down
Available in two 64-lead LFCSP packages
Residual phase noise @ 250 MHz
10 Hz offset: −113 dBc/Hz
1 kHz offset: −133 dBc/Hz
100 kHz offset: −153 dBc/Hz
40 MHz offset: −161 dBc/Hz
APPLICATIONS
Agile LO frequency synthesis
Low jitter, fine tune clock generation
Test and measurement equipment
Wireless base stations and controllers
Secure communications
Fast frequency hopping
GENERAL DESCRIPTION
The AD9912 is a direct digital synthesizer (DDS) that features
an integrated 14-bit digital-to-analog converter (DAC). The
AD9912 features a 48-bit frequency tuning word (FTW) that
can synthesize frequencies in step sizes no larger than 4 μHz.
Absolute frequency accuracy can be achieved by adjusting the
DAC system clock.
The AD9912 also features an integrated system clock phase-
locked loop (PLL) that allows for system clock inputs as low
as 25 MHz.
The AD9912 operates over an industrial temperature range,
spanning −40°C to +85°C.
BASIC BLOCK DIAGRAM
FDBK_IN
DAC_OUT
AD9912
S1 TO S4
OUT
OUT_CMOS
FILTER
SYSTEM CLOCK
MULTIPLIER
SERIAL PORT,
I/O LOGIC
CLOCK
OUTPUT
DRIVERS
DIGITAL
INTERFACE
06763-
001
DIRECT
DIGITAL
SYNTHESIS
CORE
STARTUP
CONFIGURATION
LOGIC
Figure 1.
Document Outline
- Features
- Applications
- General Description
- Basic Block Diagram
- Revision History
- Specifications
- Absolute Maximum Ratings
- Pin Configuration and Function Descriptions
- Typical Performance Characteristics
- Input/Output Termination Recommendations
- Theory of Operation
- Thermal Performance
- Power-Up
- Power Supply Partitioning
- Serial Control Port
- I/O Register Map
- I/O Register Descriptions
- Serial Port Configuration (Register 0x0000 to Register 0x0005)
- Power-Down and Reset (Register 0x0010 to Register 0x0013)
- System Clock (Register 0x0020 to Register 0x0022)
- CMOS Output Divider (S-Divider) (Register 0x0100 to Register 0x0106)
- Frequency Tuning Word (Register 0x01A0 to Register 0x01AD)
- Register 0x01A0 to Register 0x01A5—Reserved
- Register 0x01A6—FTW0 (Frequency Tuning Word)
- Register 0x01A7—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01A8—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01A9—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01AA—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01AB—FTW0 (Frequency Tuning Word) (Continued)
- Register 0x01AC—Phase
- Register 0x01AD—Phase (Continued)
- Doubler and Output Drivers (Register 0x0200 to Register 0x0201)
- Calibration (User-Accessible Trim) (Register 0x0400 to Register 0x0410)
- Harmonic Spur Reduction (Register 0x0500 to Register 0x0509)
- Outline Dimensions