AD549

Data Sheet

Rev. K | Page 2 of 18

TABLE OF CONTENTS

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

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

Connection Diagram ....................................................................... 1

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

Product Highlights ........................................................................... 1

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

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

Absolute Maximum Ratings............................................................ 5

ESD Caution.................................................................................. 5

Typical Performance Characteristics ............................................. 6

Functional Description .................................................................. 10

Minimizing Input Current ........................................................ 10

Circuit Board Notes ................................................................... 10

Offset Nulling ............................................................................. 11

AC Response with High Value Source and Feedback

Resistance .................................................................................... 12

Common-Mode Input Voltage Overload................................ 12

Differential Input Voltage Overload ........................................ 13

Input Protection ......................................................................... 13

Sample-and-Difference Circuit to Measure Electrometer

Leakage Currents........................................................................ 13

Photodiode Interface ................................................................. 14

Log Ratio Amplifier ................................................................... 15

Temperature Compensated pH Probe Amplifier................... 16

Outline Dimensions ....................................................................... 18

Ordering Guide .......................................................................... 18

REVISION HISTORY

2/15—Rev. J to Rev. K

Updated Outline Dimensions ....................................................... 18

12/14—Rev. I to Rev. J

Added L Model ...................................................................Universal

Changes to Features Section and Applications Section............... 1

Changes to Table 1............................................................................ 3

Changes to Table 2............................................................................ 5

Changes to Log Ratio Amplifier Section..................................... 15

Changes to Temperature Compensated pH Probe

Amplifier Section............................................................................ 16

Changes to Ordering Guide .......................................................... 18

6/14—Rev. H to Rev. I

Deleted L Model............................................................. Throughout

Change to Features Section ............................................................. 1

Changes to Input Offset Voltage Parameter and Input Voltage

Noise Parameter, Table 1.................................................................. 3

Changes to Ordering Guide .......................................................... 18

3/08—Rev. G to Rev. H

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

Changes to Figure 1.......................................................................... 1

Deleted Package Option Parameter ............................................... 4

Inserted ESD Caution ...................................................................... 5

Changes to Figure 2, Figure 3, and Figure 7.................................. 6

Changes to Figure 11........................................................................ 7

Changes to Figure 17........................................................................ 8

Changes to Figure 41...................................................................... 14

7/07—Rev. F to Rev. G

Changes to Figure 45...................................................................... 16

Changes to Temperature Compensated pH Probe

Amplifier Section............................................................................ 17

Changes to Figure 46...................................................................... 17

Changes to Ordering Guide .......................................................... 18

5/06—Rev. E to Rev. F

Removed ESD Caution .....................................................................5

8/05—Rev. D to Rev. E

Change to Figure 22 ..........................................................................9

5/04—Rev. C to Rev. D

Updated Format..................................................................Universal

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

Updated Outline Dimensions....................................................... 18

Added Ordering Guide.................................................................. 18

10/02—Rev. B to Rev. C

Deleted Product Highlights #5 ........................................................1

Edits to Specifications .......................................................................3

Deleted Metallization Photograph ..................................................3

Updated Outline Dimensions....................................................... 13

7/02—Rev. A to Rev. B

Edits to Specifications .......................................................................2