AT42QT1012
AT42QT1012 Data Sheet
Introduction
The AT42QT1012 (QT1012) is a single key device featuring a touch on/touch off (toggle) output with a
programmable auto switch-off capability. The device is One-channel Toggle-mode QTouch
®
Touch
Sensor IC with Power Management Functions.
The QT1012 features a digital burst mode charge-transfer sensor designed specifically for touch controls
and a unique “green” feature - the timeout function, which can turn off power after a time delay.
Features
•
Number of Keys:
One, toggle mode (touch-on / touch-off), plus programmable auto-off delay and external
cancel
– Configurable as either a single key or a proximity sensor
Technology:
– Patented spread-s
6 mm x 6 mm or larger (panel thickness dependent); widely different sizes and shapes
possible
Electrode design:
– Solid or ring electrode shapes
PCB Layers required:
– One
Electrode materials:
– Etched copper, silver, carbon, Indium Tin Oxide (ITO)
Electrode substrates:
– PCB, FPCB, plastic films, glass
Panel materials:
– Plastic, glass, composites, painted surfaces (low particle density metallic paints possible)
Panel thickness:
– Up to 12 mm glass, 6 mm plastic (electrode size and Cs dependent)
Key sensitivity:
Settable via external capacitor (Cs)
Interface:
– Digital output, active high or active low (hardware configurable)
Moisture tolerance:
– Increased moisture tolerance based on hardware design and firmware tuning
Power:
–
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©
2017 Microchip Technology Inc.
Datasheet
DS40001948A-page 1
AT42QT1012
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– 1.8 V – 5.5 V; 32 µA at 1.8 V
Package:
– 6-pin SOT23-6 (3 x 3 mm) RoHS compliant
– 8-pin UDFN/USON (2 x 2 mm) RoHS compliant
Signal processing:
– Self-calibration, auto drift compensation, noise filtering
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©
2017 Microchip Technology Inc.
Datasheet
DS40001948A-page 2
Table of Contents
Introduction......................................................................................................................1
Features.......................................................................................................................... 1
1. Pinout and Schematic................................................................................................5
1.1.
1.2.
1.3.
Pinout Configurations................................................................................................................... 5
Pin Descriptions........................................................................................................................... 5
Schematics...................................................................................................................................6
2. Overview of the AT42QT1012................................................................................... 7
2.1.
2.2.
2.3.
2.4.
2.5.
Introduction...................................................................................................................................7
Basic Operation............................................................................................................................7
Electrode Drive.............................................................................................................................7
Sensitivity..................................................................................................................................... 8
Moisture Tolerance....................................................................................................................... 8
3. Operation Specifics................................................................................................. 10
3.1.
3.2.
3.3.
3.4.
3.5.
3.6.
3.7.
3.8.
3.9.
3.10.
3.11.
3.12.
Acquisition Modes...................................................................................................................... 10
Detect Threshold........................................................................................................................ 10
Detect Integrator.........................................................................................................................11
Recalibration Timeout.................................................................................................................11
Forced Sensor Recalibration...................................................................................................... 11
Drift Compensation.....................................................................................................................11
Response Time.......................................................................................................................... 12
Spread Spectrum....................................................................................................................... 12
Output Polarity Selection............................................................................................................12
Output Drive............................................................................................................................... 13
Auto-Off Delay............................................................................................................................13
Examples of Typical Applications............................................................................................... 21
4. Circuit Guidelines.................................................................................................... 22
4.1.
4.2.
4.3.
4.4.
4.5.
More Information........................................................................................................................ 22
Sample Capacitor.......................................................................................................................22
Rs Resistor.................................................................................................................................22
Power Supply and PCB Layout.................................................................................................. 22
Power On................................................................................................................................... 23
5. Specifications.......................................................................................................... 24
5.1.
5.2.
5.3.
5.4.
5.5.
5.6.
5.7.
Absolute Maximum Specifications..............................................................................................24
Recommended Operating Conditions........................................................................................ 24
AC Specifications....................................................................................................................... 24
Signal Processing.......................................................................................................................25
DC Specifications....................................................................................................................... 25
Mechanical Dimensions............................................................................................................. 26
Part Marking............................................................................................................................... 28
©
2017 Microchip Technology Inc.
Datasheet
DS40001948A-page 3
AT42QT1012
5.8.
5.9.
Part Number............................................................................................................................... 28
Moisture Sensitivity Level (MSL)................................................................................................ 29
6. Associated Documents............................................................................................30
7. Revision History.......................................................................................................31
The Microchip Web Site................................................................................................ 32
Customer Change Notification Service..........................................................................32
Customer Support......................................................................................................... 32
Microchip Devices Code Protection Feature................................................................. 32
Legal Notice...................................................................................................................33
Trademarks................................................................................................................... 33
Quality Management System Certified by DNV.............................................................34
Worldwide Sales and Service........................................................................................35
©
2017 Microchip Technology Inc.
Datasheet
DS40001948A-page 4
AT42QT1012
1.
1.1
1.1.1
Pinout and Schematic
Pinout Configurations
6-pin SOT23-6
OUT
VSS
SNSK
1
2
3
6
TIME
VDD
SNS
QT1012
5
4
1.1.2
8-pin UDFN/USON
Pin 1 ID
SNSK
N/C
N/C
VSS
1
2
3
4
8
SNS
VDD
TIME
OUT
QT1012
7
6
5
1.2
Pin Descriptions
If Unused, Connect
To...
Table 1-1. Pin Listing
6-Pin 8-Pin Name Type Description
1
2
3
4
5
4
1
8
OUT
VSS
O
(1)
P
Output state. To switched circuit and output polarity selection
resistor (Rop)
Ground
Sense pin. To Cs capacitor and to sense electrode
Sense pin. To Cs capacitor and multiplier configuration resistor
(Rm). Rm must be fitted and connected to either VSS or VDD.
See
Section 3.11.4
for details.
Power
Timeout configuration pin. Must be connected to either VSS,
VDD, OUT or an RC network. See
Section 3.11
for details.
Not connected
Not connected
Do not connect
Do not connect
Cs + key
Cs
SNSK I/O
SNS
I/O
5
6
—
—
7
6
2
3
VDD
P
TIME I
N/C
N/C
—
—
©
2017 Microchip Technology Inc.
Datasheet
DS40001948A-page 5