AD8420

Data Sheet

Rev. A | Page 2 of 26

TABLE OF CONTENTS

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

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

Pin Configuration............................................................................. 1

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

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

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

Absolute Maximum Ratings............................................................ 7

Thermal Resistance ...................................................................... 7

ESD Caution.................................................................................. 7

Pin Configuration and Function Descriptions............................. 8

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

Theory of Operation ...................................................................... 19

Architecture................................................................................. 19

Setting the Gain .......................................................................... 19

Gain Accuracy ............................................................................ 20

Input Voltage Range................................................................... 20

Input Protection ......................................................................... 20

Layout .......................................................................................... 21

Driving the Reference Pin......................................................... 21

Input Bias Current Return Path ............................................... 22

Radio Frequency Interference (RFI)........................................ 22

Output Buffering ........................................................................ 23

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

AD8420 in Electrocardiography (ECG).................................. 24

Classic Bridge Circuit ................................................................ 25

4 mA to 20 mA Single-Supply Receiver .................................. 25

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

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

REVISION HISTORY

1/15—Rev. 0 to Rev. A

Changes to Features Section............................................................ 1

Changes to Specifications Section .................................................. 3

Changes to Quiescent Current Parameter, Table 2 ...................... 4

Changes to Common-Mode Rejection Ratio (CMRR)

Parameter, Table 3 and Quiescent Current Parameter, Table 3.........5

Changes to ESD Parameter, Table 4 ............................................... 7

Changes to Figure 9, Figure 11, Figure 13, and Figure 14......... 10

Changes to Figure 15, Figure 16 Caption, Figure 18 Caption,

and Figure 20 Caption.................................................................... 11

Changes to Figure 38...................................................................... 14

Change to Figure 40 Caption ........................................................ 15

Changes to Figure 56 Caption....................................................... 17

Changes to Figure 57 Caption....................................................... 18

Changes to Figure 58 and Architecture Section ......................... 19

Changes to Gain Accuracy Section .............................................. 20

Changes to Driving the Reference Pin Section........................... 21

Changes to Output Buffering Section.......................................... 23

Changes to 4 mA to 20 mA Single-Supply Receiver Section.... 25

3/12—Revision 0: Initial Version