AD7781 Analog Devices, AD7781 Datasheet - Page 2

• Manufacturer Part Number: AD7781
• Description: 20-Bit, Pin-Programmable, Ultralow Power Sigma-Delta ADC
• Manufacturer: Analog Devices

Specifications of AD7781

• Resolution (bits): 20bit
• # Chan: 1
• Sample Rate: 16.7SPS
• Interface: Ser,SPI
• Analog Input Type: Diff-Bip
• Ain Range: ± (Vref/Gain) ,10V p-p,78 mV p-p
• Adc Architecture: Sigma-Delta
• Pkg Type: SOIC,SOP

AD7781
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications ..................................................................................... 3
Absolute Maximum Ratings ............................................................ 6
Pin Configurations and Function Descriptions ........................... 7
Typical Performance Characteristics ............................................. 8
Output Noise and Resolution........................................................ 10
Theory of Operation ...................................................................... 11
REVISION HISTORY
5/09—Revision 0: Initial Version
Timing Characteristics ................................................................ 5
Thermal Resistance ...................................................................... 6
ESD Caution .................................................................................. 6
Filter, Data Rate, and Settling Time ......................................... 11
Rev. 0 | Page 2 of 16
Applications Information .............................................................. 14
Outline Dimensions ....................................................................... 16
Gain .............................................................................................. 11
Power-Down/Reset ( PDRST ) ................................................... 12
Analog Input Channel ............................................................... 12
Bipolar Configuration ................................................................ 12
Data Output Coding .................................................................. 12
Reference ..................................................................................... 12
Bridge Power-Down Switch ...................................................... 12
Digital Interface .......................................................................... 13
Weigh Scales ................................................................................ 14
AD7781 Performance in a Weigh Scale System ......................... 14
EMI Recommendations ............................................................. 14
Grounding and Layout .............................................................. 15
Ordering Guide .......................................................................... 16