ADA4939-1/ADA4939-2

Data Sheet

Rev. A | Page 2 of 24

TABLE OF CONTENTS

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

 

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

 

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

 

Functional Block Diagrams............................................................. 1

 

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

 

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

 

5 V Operation ............................................................................... 3

 

3.3 V Operation ............................................................................ 5

 

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

 

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

 

Maximum Power Dissipation ..................................................... 7

 

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

 

Pin Configurations and Function Descriptions ........................... 8

 

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

 

Test Circuits..................................................................................... 15

 

Operational Description................................................................ 16

 

Definition of Terms.................................................................... 16

 

Theory of Operation ...................................................................... 17

 

Analyzing an Application Circuit ............................................ 17

 

Setting the Closed-Loop Gain .................................................. 17

 

Stable for Gains ≥2 ..................................................................... 17

 

Estimating the Output Noise Voltage ...................................... 17

 

Impact of Mismatches in the Feedback Networks................. 18

 

Calculating the Input Impedance for an Application Circuit

....................................................................................................... 19

 

Input Common-Mode Voltage Range ..................................... 21

 

Input and Output Capacitive AC Coupling............................ 21

 

Minimum RG Value of 50 Ω ...................................................... 21

 

Setting the Output Common-Mode Voltage .......................... 21

 

Layout, Grounding, and Bypassing.............................................. 22

 

High Performance ADC Driving ................................................. 23

 

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

 

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

 

REVISION HISTORY

5/2016—Rev. 0 to Rev. A

Changed ADA4939 to ADA4939-1/ADA4939-2, CP-16-2 to

CP-16-21, and CP-24-1 to CP-24-10........................... Throughout

Changes to Figure 5, Figure 6, Table 9, and Table 10................... 8

Changes to Figure 54...................................................................... 23

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

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

5/2008—Revision 0: Initial Version