400 MSPS, 14-Bit, 1.8 V CMOS Direct Digital Synthesizer Data Sheet AD9953 FEATURES PLL REFCLK multiplier (4 to 20) Internal oscillator, can be driven by a single crystal 400 MSPS internal clock speed Phase modulation capability Integrated 14-bit DAC Multichip synchronization 32-bit tuning word Phase noise 120 dBc/Hz at 1 kHz offset (DAC output) Excellent dynamic performance APPLICATIONS >80 dB SFDR at 160 MHz (100 kHz offset) A OUT Agile VHF/UHF LO frequency synthesis Serial input/output (I/O) control FM chirp source for radar and scanning systems 1.8 V power supply Nonlinear-shaped PSK/FSK modulator Software and hardware controlled power-down Test and measurement equipment 48-lead TQFP/EP package FUNCTIONAL BLOCK DIAGRAM DDS CORE AD9953 PHASE RAM ACCUMULATOR DATA 1024 32 PHASE DAC R M SET STATIC RAM 32 OFFSET U 1 Z X 19 14 IOUT COS(X) DAC IOUT SYSTEM CLOCK 14 1 Z MUX SYNC IN 3 32 PHASE 32 14 14 OFFSET 10 WORD RAM DATA <31:18> OSK TIMING AND CONTROL LOGIC I/O UPDATE PWRDWNCTL 0 M SYNC SYNC CLK U CONTROL REGISTERS 4 X OSCILLATOR/BUFFER M SYSTEM U 4 20 CLOCK REFCLK X CLOCK REFCLK MULTIPLIER ENABLE CRYSTAL OUT PS<1:0> I/O PORT RESET Figure 1. Rev. B Document Feedback 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20042017 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. RAM ADDRESS RAM DATA RAM CONTROL DDS CLOCK FREQUENCY TUNING WORD DDS CLOCK PHASE ACCUMULATOR RESET 03357-0-001AD9953 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Component Blocks ..................................................................... 12 Applications ....................................................................................... 1 Modes of Operation ................................................................... 19 Revision History ............................................................................... 2 Programming AD9953 Features .............................................. 22 General Description ......................................................................... 3 Serial Port Operation ................................................................. 25 Electrical Specifications ................................................................... 4 Instruction Byte .......................................................................... 27 Absolute Maximum Ratings ............................................................ 6 Serial Interface Port Pin Description ....................................... 27 ESD Caution .................................................................................. 6 MSB/LSB Transfers .................................................................... 27 Pin Configuration ............................................................................. 7 Suggested Application Circuits ..................................................... 29 Pin Function Descriptions .............................................................. 8 Outline Dimensions ....................................................................... 30 Typical Performance Characteristics ............................................. 9 Ordering Guide .......................................................................... 30 Theory of Operation ...................................................................... 12 REVISION HISTORY Changes to Figure 22 ...................................................................... 25 1/2017Rev. A to Rev. B Changes to Serial Port Operation Section .................................. 25 Changes to Features Section............................................................ 1 Changes to Serial Interface Port Pin Description Section ........ 27 Changes to Ordering Guide .......................................................... 30 Changes to Figure 29 ...................................................................... 29 Updated Outline Dimensions ....................................................... 30 5/2009Rev. 0 to Rev. A Changes to Ordering Guide .......................................................... 30 Changes to Absolute Maximum Ratings Section ......................... 6 Changes to Table 3 ............................................................................ 8 1/2004Revision 0: Initial Version Changes to Table 5 .......................................................................... 14 Rev. B Page 2 of 32