Datasheet

AD7946
Rev. A | Page 2 of 24
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Application Diagram........................................................................ 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Timing Specifications .................................................................. 5
Absolute Maximum Ratings............................................................ 6
ESD Caution.................................................................................. 6
Pin Configurations and Function Descriptions ........................... 7
Typical Performance Characteristics ............................................. 8
Ter mi no lo g y .................................................................................... 11
Theory of Operation ...................................................................... 12
Circuit Information.................................................................... 12
Converter Operation.................................................................. 12
Typical Connection Diagram ................................................... 13
Analog Input ............................................................................... 13
Driver Amplifier Choice............................................................ 14
Voltage Reference Input ............................................................ 14
Power Supply............................................................................... 15
Supplying the ADC from the Reference.................................. 15
Single-Supply Application......................................................... 15
Digital Interface.......................................................................... 16
CS
MODE 3-Wire, No BUSY Indicator .................................. 17
CS
Mode 3-Wire with BUSY Indicator ................................... 18
CS
Mode 4-Wire, No BUSY Indicator..................................... 19
CS
Mode 4-Wire with BUSY Indicator ................................... 20
Chain Mode, No BUSY Indicator ............................................ 21
Chain Mode with BUSY Indicator........................................... 22
Application Guidelines .................................................................. 23
Layout .......................................................................................... 23
Evaluating the AD7946’s Performance.................................... 23
Outline Dimensions ....................................................................... 24
Ordering Guide .......................................................................... 24
REVISION HISTORY
12/07—Rev. 0 to Rev. A
QFN Package Available......................................................Universal
Changes to Table 1............................................................................ 1
Changes to Table 5............................................................................ 6
Changes to Ordering Guide .......................................................... 24
7/05—Revision 0: Initial Version