AD7143 Analog Devices, AD7143 Datasheet - Page 2

• Manufacturer Part Number: AD7143
• Description: Programmable Controller for Capacitance Touch Sensors
• Manufacturer: Analog Devices

Specifications of AD7143

• Resolution (bits): 16bit
• # Chan: 8
• Sample Rate: n/a
• Interface: I²C/Ser 2-Wire,Ser
• Analog Input Type: n/a
• Ain Range: ± 2 pF (Delta C)
• Adc Architecture: Sigma-Delta
• Pkg Type: CSP

AD7143
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
Theory of Operation ...................................................................... 11
Capacitance Sensor Input Configuration.................................... 13
Capacitiance-to-Digital Converter............................................... 14
Noncontact Proximity Detection ................................................. 17
REVISION HISTORY
1/07—Revision 0: Initial Version
I
ESD Caution.................................................................................. 6
Capacitance Sensing Theory..................................................... 11
Operating Modes........................................................................ 12
CIN Input Multiplexer Setup .................................................... 13
Oversampling the CDC Output ............................................... 14
Capacitance Sensor Offset Control.......................................... 14
Conversion Sequencer ............................................................... 14
CDC Conversion Sequence Time ............................................ 15
CDC Conversion Results........................................................... 16
Recalibration ............................................................................... 17
2
C Timing Specifications............................................................ 5
Rev. 0 | Page 2 of 56
Environmental Calibration ........................................................... 22
Adaptive Threshold and Sensitivity ............................................. 25
Interrupt Output............................................................................. 26
Serial Interface ................................................................................ 28
PCB Design Guidelines ................................................................. 31
Power-Up Sequence ....................................................................... 32
Typical Application Circuits ......................................................... 33
Register Map ................................................................................... 34
Detailed Register Descriptions ..................................................... 35
Outline Dimensions ....................................................................... 55
Proximity Sensitivity.................................................................. 17
Slow FIFO.................................................................................... 19
SLOW_FILTER_UPDATE_LVL .............................................. 19
Capacitance Sensor Behavior without Calibration................ 22
Capacitance Sensor Behavior with Calibration...................... 23
CDC Conversion Complete Interrupt..................................... 26
Sensor Touch Interrupt.............................................................. 26
I
Capacitive Sensor Board Mechanical Specifications ............. 31
Chip Scale Packages ................................................................... 31
Bank 1 Registers ......................................................................... 35
Bank 2 Registers ......................................................................... 43
Bank 3 Registers ......................................................................... 47
Ordering Guide .......................................................................... 55
2
C Compatible Interface........................................................... 28