AD9958

Rev. 0 | Page 2 of 40

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications....................................................................................... 1

Functional Block Diagram .............................................................. 1

General Description ......................................................................... 3

Specifications..................................................................................... 4

Absolute Maximum Ratings............................................................ 8

ESD Caution.................................................................................. 8

Equivalent Input and Output Circuits....................................... 8

Pin Configuration and Function Descriptions............................. 9

Typical Performance Characteristics ........................................... 11

Application Circuits ....................................................................... 14

Theory of Operation ...................................................................... 17

DDS Core..................................................................................... 17

D/A Converter ............................................................................ 17

Modes of Operation ....................................................................... 18

Channel Constraint Guidelines ................................................ 18

Power Supplies ............................................................................ 18

Single-Tone Mode ...................................................................... 18

Reference Clock Modes ............................................................. 19

Scalable DAC Reference Current Control Mode ................... 20

Power-Down Functions............................................................. 20

Modulation Mode....................................................................... 20

Modulation Using SDIO Pins for RU/RD............................... 22

Linear Sweep (Shaped) Modulation Mode ............................. 22

Linear Sweep—No-Dwell Mode............................................... 24

Sweep and Phase Accumulator Clearing Functions .............. 25

Output Amplitude Control Mode............................................ 26

Synchronizing Multiple AD9958 Devices ................................... 27

Automatic Mode Synchronization ........................................... 27

Manual Software Mode Synchronization................................ 27

Manual Hardware Mode Synchronization.............................. 27

I/O_Update, SYNC_CLK, and System Clock Relationships 28

Serial I/O Port ................................................................................. 29

Overview ..................................................................................... 29

Instruction Byte Description .................................................... 30

Serial I/O Port Pin Description ................................................ 30

Serial I/O Port Function Description ...................................... 30

MSB/LSB Transfer Description ................................................ 30

Serial I/O Modes of Operation................................................. 31

Register Maps.................................................................................. 34

Control Register Map ................................................................ 34

Channel Register Map ............................................................... 35

Profile Register Map................................................................... 35

Control Register Descriptions ...................................................... 36

Channel Select Register (CSR) ................................................. 36

Channel Function Register (CFR) Description...................... 37

Outline Dimensions ....................................................................... 39

Ordering Guide .......................................................................... 39

REVISION HISTORY

9/05—Revision 0: Initial Version