AD9956

Rev. B | Page 2 of 32

TABLE OF CONTENTS

Product Overview............................................................................. 3

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

Loop Measurement Conditions ................................................. 9

Absolute Maximum Ratings ......................................................... 10

ESD Caution................................................................................ 10

Pin Configuration and Function Descriptions .......................... 11

Typical Performance Characteristics........................................... 13

Typical Application Circuits......................................................... 16

Application Circuit Explanations ............................................ 17

General Description....................................................................... 18

DDS Core .................................................................................... 18

PLL Circuitry .............................................................................. 18

CML Driver................................................................................. 19

Modes of Operation....................................................................... 20

DDS Modes of Operation ......................................................... 20

Synchronization Modes for Multiple Devices ............................. 20

Serial Port Operation..................................................................... 22

Instruction Byte.......................................................................... 23

Serial Interface Port Pin Description ...................................... 23

MSB/LSB Transfers.................................................................... 23

Register Map and Description...................................................... 24

Control Function Register Descriptions................................. 27

Outline Dimensions....................................................................... 32

Ordering Guide .......................................................................... 32

REVISION HISTORY

8/2020—Rev. A to Rev. B

Changes to Figure 3........................................................................ 11

Updated Outline Dimensions....................................................... 32

Changes to Ordering Guide.......................................................... 32

9/2004—Rev. 0 to Rev. A

Changes to the Pin Configuration ............................................... 11

Changes to the Pin Function Descriptions................................. 12

Changes to Table 5 ......................................................................... 24

Changes to CFR2<15:12> PLLREF Divider

Control Bits (÷N) ........................................................................... 31

Changes to CFR2<11:8> PLLREF Divider

Control Bits (÷M)........................................................................... 31

Changes to Ordering Guide.......................................................... 32

7/2004—Revision: Initial Version