Datasheet

Table of Contents
Introduction......................................................................................................................1
Features.......................................................................................................................... 1
1. Pinout and Schematic................................................................................................5
1.1. Pinout Configurations................................................................................................................... 5
1.2. Pin Descriptions........................................................................................................................... 5
1.3. Schematics...................................................................................................................................6
2. Overview of the AT42QT1012................................................................................... 7
2.1. Introduction...................................................................................................................................7
2.2. Basic Operation............................................................................................................................7
2.3. Electrode Drive.............................................................................................................................7
2.4. Sensitivity..................................................................................................................................... 8
2.5. Moisture Tolerance....................................................................................................................... 8
3. Operation Specifics................................................................................................. 10
3.1. Acquisition Modes...................................................................................................................... 10
3.2. Detect Threshold........................................................................................................................ 10
3.3. Detect Integrator.........................................................................................................................11
3.4. Recalibration Timeout.................................................................................................................11
3.5. Forced Sensor Recalibration...................................................................................................... 11
3.6. Drift Compensation.....................................................................................................................11
3.7. Response Time.......................................................................................................................... 12
3.8. Spread Spectrum....................................................................................................................... 12
3.9. Output Polarity Selection............................................................................................................12
3.10. Output Drive............................................................................................................................... 13
3.11. Auto-Off Delay............................................................................................................................13
3.12. Examples of Typical Applications...............................................................................................21
4. Circuit Guidelines.................................................................................................... 22
4.1. More Information........................................................................................................................ 22
4.2. Sample Capacitor.......................................................................................................................22
4.3. Rs Resistor.................................................................................................................................22
4.4. Power Supply and PCB Layout.................................................................................................. 22
4.5. Power On................................................................................................................................... 23
5. Specifications.......................................................................................................... 24
5.1. Absolute Maximum Specifications..............................................................................................24
5.2. Recommended Operating Conditions........................................................................................ 24
5.3. AC Specifications....................................................................................................................... 24
5.4. Signal Processing.......................................................................................................................25
5.5. DC Specifications....................................................................................................................... 25
5.6. Mechanical Dimensions............................................................................................................. 26
5.7. Part Marking............................................................................................................................... 28
© 2017 Microchip Technology Inc.
Datasheet
DS40001948A-page 3