AD7765

Rev. 0 | Page 2 of 32

TABLE OF CONTENTS

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

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

General Description ......................................................................... 1

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

Revision History ............................................................................... 2

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

Timing Specifications .................................................................. 6

Timing Diagrams.......................................................................... 7

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

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

Pin Configuration and Functional Descriptions.......................... 9

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

Terminology .................................................................................... 14

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

Σ-Δ Modulation and Digital Filtering...................................... 15

AD7765 Input Structure ................................................................ 16

On-Chip Differential Amplifier ............................................... 17

Modulator Input Structure........................................................ 18

AD7765 Interface............................................................................ 19

Reading Data............................................................................... 19

Reading Status and Other Registers......................................... 19

Writing to the AD7765 .............................................................. 19

AD7765 Functionality.................................................................... 20

Synchronization.......................................................................... 20

Overrange Alerts ........................................................................ 20

Power Modes............................................................................... 20

Decimation Rate Pin.................................................................. 21

Daisy Chaining ............................................................................... 22

Reading Data in Daisy-Chain Mode ....................................... 22

Writing Data in Daisy-Chain Mode ........................................ 23

Clocking the AD7765 .................................................................... 24

MCLK Jitter Requirements ....................................................... 24

Decoupling and Layout Information ........................................... 25

Supply Decoupling ..................................................................... 25

Reference Voltage Filtering ....................................................... 25

Differential Amplifier Components ........................................ 25

Layout Considerations............................................................... 25

Using the AD7765 ...................................................................... 26

Bias Resistor Selection ............................................................... 26

AD7765 Registers ........................................................................... 27

Control Register ......................................................................... 27

Status Register............................................................................. 27

Gain Register—Address 0x0004............................................... 28

Overrange Register—Address 0x0005..................................... 28

Outline Dimensions ....................................................................... 29

Ordering Guide .......................................................................... 29

REVISION HISTORY

6/07—Revision 0: Initial Version