AD7944

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TABLE OF CONTENTS

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

 

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

 

Application Diagram........................................................................ 1

 

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

 

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

 

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

 

Timing Specifications .................................................................. 5

 

Absolute Maximum Ratings............................................................ 6

 

ESD Caution.................................................................................. 6

 

Pin Configuration and Function Descriptions............................. 7

 

Typical Performance Characteristics ............................................. 9

 

Terminology .................................................................................... 12

 

Theory of Operation ...................................................................... 13

 

Circuit Information.................................................................... 13

 

Converter Operation.................................................................. 13

 

Conversion Modes of Operation.............................................. 13

 

Typical Connection Diagram ................................................... 14

 

Analog Inputs ............................................................................. 15

 

Driver Amplifier Choice ........................................................... 15

 

Voltage Reference Input ............................................................ 16

 

Power Supply............................................................................... 16

 

Digital Interface .............................................................................. 17

 

Data Reading Options ............................................................... 18

 

CS Mode, 3-Wire Without Busy Indicator ............................. 19

 

CS Mode, 3-Wire with Busy Indicator .................................... 20

 

CS Mode, 4-Wire Without Busy Indicator ............................. 21

 

CS Mode, 4-Wire with Busy Indicator .................................... 22

 

Chain Mode Without Busy Indicator ...................................... 23

 

Chain Mode with Busy Indicator ............................................. 24

 

Applications Information .............................................................. 25

 

Layout .......................................................................................... 25

 

Evaluating AD7944 Performance............................................. 25

 

Outline Dimensions ....................................................................... 27

 

Ordering Guide .......................................................................... 27

 

REVISION HISTORY

10/09—Revision 0: Initial Version