EVAL-AD7147EBZ View Datasheet(PDF) - Analog Devices
Part Name
Description
Manufacturer
EVAL-AD7147EBZ
Analog Devices
EVAL-AD7147EBZ Datasheet PDF : 69 Pages
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AD7147A
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
General Description ......................................................................... 1
Functional Block Diagram .............................................................. 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Average Current Specifications .................................................. 4
SPI Timing Specifications (AD7147A)...................................... 5
I2C Timing Specifications (AD7147A-1) .................................. 6
Absolute Maximum Ratings............................................................ 7
ESD Caution.................................................................................. 7
Pin Configurations and Function Descriptions ........................... 8
Typical Performance Characteristics ............................................. 9
Theory of Operation ...................................................................... 11
Capacitance Sensing Theory..................................................... 11
BIAS Pin....................................................................................... 12
Operating Modes........................................................................ 12
Capacitance-to-Digital Converter................................................ 14
Oversampling the CDC Output ............................................... 14
Capacitance Sensor Offset Control.......................................... 14
Conversion Sequencer ............................................................... 14
CDC Conversion Sequence Time ............................................ 16
CDC Conversion Results........................................................... 16
Capacitance Sensor Input Configuration.................................... 17
CINx Input Multiplexer Setup .................................................. 17
Single-Ended Connections to the CDC .................................. 17
Noncontact Proximity Detection ................................................. 18
Recalibration ............................................................................... 18
Proximity Sensitivity .................................................................. 18
FF_SKIP_CNT............................................................................ 21
Environmental Calibration ........................................................... 23
REVISION HISTORY
12/09—Rev. A to Rev. B
Changes to Figure 1 .......................................................................... 1
Changes to Figure 5, Figure 6, and Pin Description for B2 ........ 8
Changes to Figure 59 and Figure 60............................................. 39
Changes to Ordering Guide .......................................................... 68
Capacitance Sensor Behavior Without Calibration............... 23
Threshold Equations.................................................................. 23
Capacitance Sensor Behavior with Calibration...................... 24
Slow FIFO.................................................................................... 24
SLOW_FILTER_UPDATE_LVL .............................................. 24
Adaptive Threshold and Sensitivity ............................................. 25
Interrupt Output............................................................................. 27
CDC Conversion-Complete Interrupt .................................... 27
Sensor-Touch Interrupt ............................................................. 27
GPIO INT Output Control ....................................................... 29
Outputs ............................................................................................ 31
ACSHIELD Output .......................................................................... 31
General-Purpose Input/Output (GPIO) ................................. 31
Using the GPIO to Turn On/Off an LED................................ 31
Serial Interfaces............................................................................... 32
SPI Interface ................................................................................ 32
I2C-Compatible Interface .......................................................... 34
VDRIVE Input ................................................................................. 36
PCB Design Guidelines ................................................................. 37
Capacitive Sensor Board Mechanical Specifications ............. 37
WLCSP Package ......................................................................... 37
Power-Up Sequence ....................................................................... 38
Typical Application Circuits ......................................................... 39
Register Map ................................................................................... 40
Detailed Register Descriptions ..................................................... 41
Bank 1 Registers ......................................................................... 41
Bank 2 Registers ......................................................................... 51
Bank 3 Registers ......................................................................... 56
Outline Dimensions ....................................................................... 68
Ordering Guide .......................................................................... 68
3/09—Rev. 0 to Rev. A
Changes to Ordering Guide .......................................................... 68
1/09—Revision 0: Initial Version
Rev. B | Page 2 of 68
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