AD7981

Data Sheet

Rev. B | Page 2 of 26

TABLE OF CONTENTS

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

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

Typical Application Circuit ............................................................. 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 ............................................. 8

Terminology .................................................................................... 13

Theory of Operation ...................................................................... 14

Circuit Information.................................................................... 14

Converter Operation.................................................................. 14

Typical Connection Diagram.................................................... 15

Analog Input ............................................................................... 16

Driver Amplifier Choice ........................................................... 16

Voltage Reference Input ............................................................ 17

Power Supply............................................................................... 17

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

CS Mode, 3-Wire Without a Busy Indicator........................... 18

CS Mode, 3-Wire with a Busy Indicator ................................. 19

CS Mode, 4-Wire Without a Busy Indicator........................... 20

CS Mode, 4-Wire with a Busy Indicator ................................. 21

Chain Mode Without a Busy Indicator ................................... 22

Chain Mode with a Busy Indicator.......................................... 23

Applications Information .............................................................. 24

Printed Circuit Board (PCB) Layout ....................................... 25

Outline Dimensions....................................................................... 26

Ordering Guide .......................................................................... 26

REVISION HISTORY

7/2017—Rev. A to Rev. B

Change to Conversion Time: CNV Rising Edge to Data Available

Parameter; Table 3.............................................................................. 5

10/2016—Rev. 0 to Rev. A

Added 10-Lead FLATPACK..............................................Universal

Changes to Features Section and General Description Section . 1

Changes to Integral Nonlinearity (INL) Parameter, Table 1....... 3

Changes to Power Dissipation Parameter and Temperature

Range, Specified Performance Parameter, Table 2....................... 4

Changes to Table 4............................................................................ 6

Added Figure 5; Renumbered Sequentially .................................. 7

Changes to Figure 6, Figure 7, and Figure 8 ................................. 8

Added Figure 9, Figure 10, and Figure 11..................................... 8

Changes to Figure 12.........................................................................9

Added Figure 15 ................................................................................9

Changes to Figure 18 and Figure 21 ............................................ 10

Added Figure 22 and Figure 23 .................................................... 10

Change to Figure 26 ....................................................................... 11

Added Figure 27, Figure 28, Figure 29 ........................................ 11

Added Figure 33 and Figure 34 .................................................... 12

Change to Figure 35 Caption ....................................................... 12

Changes to Circuit Information Section ..................................... 14

Updated Outline Dimensions....................................................... 26

Changes to Ordering Guide.......................................................... 26

10/2014—Revision 0: Initial Version