9625D–AT42–05/2013
Features
QTouch
®
Sensor Channels
Up to eight keys
Integrated Haptic Engine
Haptic events may be triggered by touch detection or controlled by a host
microcontroller over SPI
Data Acquisition
QTouchADC key measurement/touch detection method
Configurable measurement timing and averaging
Spread spectrum charge transfer
Raw data from channel measurement can be read over the SPI interface
GPIO Pins
12 dedicated bi-directional GPIO pins, plus up to 4 additional pins (replacing keys)
Configurable as software PWM Drive, digital inputs or outputs
Device setup
Device configuration may be stored in NVRAM
Operation
Power-On reset and brown-out detection
Internal calibrated oscillator
Key Outline Sizes
6 mm × 6 mm or larger (panel thickness dependent); widely different sizes and shapes
possible, including solid or ring shapes
Key Spacing
7 mm or more, center to center (panel thickness dependent)
Layers required
One
Electrode Materials:
Etched copper, silver, carbon, ITO
Electrode Substrates:
PCB materials; polyamide FPCB; PET films, glass
Panel materials:
Plastic, glass, composites, painted surfaces (low particle density metallic paints
possible)
Panel Thickness:
Up to 10 mm glass, 5 mm plastic (electrode size dependent)
Key Sensitivity:
Individually configured over SPI interface
Signal Processing:
Self-calibration, auto drift compensation, noise filtering
Patented Adjacent Key Suppression
®
(AKS
®
) technology to ensure accurate key
detection
Interface:
Master/Slave SPI interface, up to 750 kHz
Object-based communications protocol
Power:
2.0 V to 5.5 V
Packages:
32-pin 5 × 5 mm QFN RoHS compliant
32-pin 7 × 7 mm TQFP RoHS compliant
Atmel AT42QT1085
Eight-key QTouch
®
Touch Sensor IC
DATASHEET
