AD7946

Rev. A | Page 2 of 24

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 Configurations and Function Descriptions ........................... 7

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

Terminology .................................................................................... 11

Theory of Operation ...................................................................... 12

Circuit Information.................................................................... 12

Converter Operation.................................................................. 12

Typical Connection Diagram ................................................... 13

Analog Input ............................................................................... 13

Driver Amplifier Choice............................................................ 14

Voltage Reference Input ............................................................ 14

Power Supply............................................................................... 15

Supplying the ADC from the Reference.................................. 15

Single-Supply Application......................................................... 15

Digital Interface.......................................................................... 16

CS MODE 3-Wire, No BUSY Indicator .................................. 17

CS Mode 3-Wire with BUSY Indicator ................................... 18

CS Mode 4-Wire, No BUSY Indicator..................................... 19

CS Mode 4-Wire with BUSY Indicator ................................... 20

Chain Mode, No BUSY Indicator ............................................ 21

Chain Mode with BUSY Indicator ........................................... 22

Application Guidelines .................................................................. 23

Layout .......................................................................................... 23

Evaluating the AD7946’s Performance.................................... 23

Outline Dimensions ....................................................................... 24

Ordering Guide .......................................................................... 24

REVISION HISTORY

12/07—Rev. 0 to Rev. A

QFN Package Available......................................................Universal

Changes to Table 1............................................................................ 1

Changes to Table 5............................................................................ 6

Changes to Ordering Guide .......................................................... 24

7/05—Revision 0: Initial Version