AD9856

Rev. C | Page 2 of 36

TABLE OF CONTENTS

Specifications..................................................................................... 3

Absolute Maximum Ratings............................................................ 5

Explanation of Test Levels ........................................................... 5

ESD Caution.................................................................................. 5

Pin Configuration and Function Descriptions............................. 6

Typical Performance Characteristics ............................................. 8

Typical Modulated Output Spectral Plots ................................. 8

Typical Single-Tone Output Spectral Plots ............................... 9

Typical Narrow-Band SFDR Spectral Plots ............................ 10

Typical Phase Noise Spectral Plots........................................... 10

Typical Plots of Output Constellations.................................... 11

Power Consumption .................................................................. 12

Serial Control Bus Register ........................................................... 13

Register Bit Definitions.............................................................. 14

Theory of Operation ...................................................................... 15

Modulation Mode Operation ................................................... 15

Input Word Rate (fW) vs. REFCLK Relationship .................... 16

I/Q Data Synchronization ......................................................... 16

Half-Band Filters (HBFs) .......................................................... 20

Cascaded Integrator Comb (CIC) Filter.................................. 21

Digital Quadrature Modulator ................................................. 23

Inverse Sinc Filter (ISF) ............................................................. 24

Direct Digital Synthesizer Function ........................................ 25

D/A Converter ............................................................................ 25

Reference Clock Multiplier ....................................................... 26

Throughput and Latency........................................................... 26

Control Interface ........................................................................ 26

General Operation of the Serial Interface............................... 26

Instruction Byte .......................................................................... 27

Serial Interface Port Pin Descriptions ..................................... 28

MSB/LSB Transfers .................................................................... 28

Notes on Serial Port Operation ................................................ 28

Programming/Writing the AD8320/AD8321 Cable Driver

Amplifier Gain Control ............................................................. 30

Understanding and Using Pin-Selectable Modulator Profiles

....................................................................................................... 31

Power Dissipation Considerations........................................... 31

AD9856 Evaluation Board ........................................................ 32

Support ........................................................................................ 32

Outline Dimensions ....................................................................... 35

Ordering Guide .......................................................................... 35

REVISION HISTORY

1/05—Rev. B to Rev. C

Updated Format..................................................................Universal

Changes to Table 2............................................................................ 5

Relationship Section.................................................................. 16

Changes to Cascaded Integrator Comb (CIC) Filter Section ... 21

Updates to Direct Digital Synthesizer Function Section........... 25

Added Support Section.................................................................. 32

Updated Outline Dimensions ....................................................... 35

Changes to Ordering Guide .......................................................... 35

9/99—Rev. A to Rev. B