Datasheet

AD420 Data Sheet
TABLE OF CONTENTS
Features .............................................................................................. 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Product Highlights ........................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 5
ESD Caution .................................................................................. 5
Pin Configuration and Function Descriptions ............................. 6
Timing Requirements ...................................................................... 7
Three-Wire Interface ................................................................... 7
Three-Wire Interface Fast Edges on Digital Input ................... 7
Asynchronous Interface ............................................................... 7
Terminology ...................................................................................... 8
Theory of Operation ........................................................................ 9
Applications Information .............................................................. 10
Current Output ........................................................................... 10
Driving Inductive Loads ............................................................ 10
Voltage-Mode Output ................................................................ 10
Optional Span and Zero Trim .................................................. 10
Three-Wire Interface ................................................................. 11
Using Multiple DACS with Fault Detect ................................. 11
Asynchronous Interface Using Optocouplers ........................ 11
Microprocessor Interface............................................................... 12
AD420-To-MC68HC11 (SPI Bus) Interface ........................... 12
AD420 to Microwire Interface ................................................. 12
External Boost Function............................................................ 13
AD420 Protection ........................................................................... 14
Transient Voltage Protection .................................................... 14
Board Layout And Grounding ................................................. 14
Power Supplies and Decoupling ............................................... 14
Outline Dimensions ....................................................................... 15
Ordering Guide .......................................................................... 15
REVISION HISTORY
3/15—Rev. H to Rev. I
Changes to Three-Wire Interface Fast Edges on Digital Input
Section ................................................................................................ 7
1/11—Rev. G to Rev. H
Changes to Figure 13 ...................................................................... 13
Changes to Ordering Guide .......................................................... 15
11/09—Rev. F to Rev. G
Updated Format .................................................................. Universal
Changes to Table 2 ............................................................................ 5
Updated Outline Dimensions ....................................................... 15
Changes to Ordering Guide .......................................................... 15
9/99—Rev. E to Rev. F
Rev. I | Page 2 of 16