AD7147 datasheet(3/73 Pages) AD

3 / 73 page

AD7147

Data Sheet

Rev. D | Page 2 of 72

TABLE OF CONTENTS

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

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

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

Functional Block Diagram .............................................................. 1

Revision History ............................................................................... 3

Specifications..................................................................................... 4

Average Current Specifications .................................................. 5

SPI Timing Specifications (AD7147)......................................... 6

I2C Timing Specifications (AD7147-1) ..................................... 7

Absolute Maximum Ratings............................................................ 8

ESD Caution.................................................................................. 8

Pin Configurations and Function Descriptions ........................... 9

Typical Performance Characteristics ........................................... 10

Theory of Operation ...................................................................... 12

Capacitance Sensing Theory..................................................... 12

BIAS Pin....................................................................................... 13

Operating Modes........................................................................ 13

Capacitiance-to-Digital Converter............................................... 15

Oversampling the CDC Output ............................................... 15

Capacitance Sensor Offset Control.......................................... 15

Conversion Sequencer ............................................................... 15

CDC Conversion Sequence Time ............................................ 17

CDC Conversion Results........................................................... 17

Capacitance Sensor Input Configuration.................................... 18

CINx Input Multiplexer Setup .................................................. 18

Single-Ended Connections to the CDC .................................. 18

Noncontact Proximity Detection ................................................. 19

Recalibration ............................................................................... 19

Proximity Sensitivity .................................................................. 19

FF_SKIP_CNT............................................................................ 22

Environmental Calibration ........................................................... 24

Capacitance Sensor Behavior Without Calibration............... 24

Threshold Equations.................................................................. 25

Capacitance Sensor Behavior with Calibration...................... 25

Slow FIFO.................................................................................... 25

SLOW_FILTER_UPDATE_LVL .............................................. 26

Adaptive Threshold and Sensitivity ............................................. 27

Interrupt Output............................................................................. 29

CDC Conversion-Complete Interrupt .................................... 29

Sensor-Touch Interrupt ............................................................. 29

GPIO INT Output Control ....................................................... 31

Outputs ............................................................................................ 33

ACSHIELD Output .......................................................................... 33

General-Purpose Input/Output (GPIO) ................................. 33

Using the GPIO to Turn On/Off an LED................................ 33

Serial Interface ................................................................................ 34

SPI Interface ................................................................................ 34

I2C-Compatible Interface .......................................................... 36

VDRIVE Input ................................................................................. 38

PCB Design Guidelines ................................................................. 39

Capacitive Sensor Board Mechanical Specifications ............. 39

Chip Scale Packages ................................................................... 39

Power-Up Sequence ....................................................................... 40

Typical Application Circuits ......................................................... 41

Detailed Register Descriptions ..................................................... 43

Bank 1 Registers ......................................................................... 43

Bank 2 Registers ......................................................................... 53

Bank 3 Registers ......................................................................... 58

Outline Dimensions ....................................................................... 70

Ordering Guide .......................................................................... 70

Automotive Products ................................................................. 70

AD7147 Datasheet(PDF) 3 Page - Analog Devices

AD7147 Datasheet(HTML) 3 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73

Datasheet Download

Link URL