Features Number of Keys: Comms Mode: 1 to 12 keys (1 to 9 if wheel or slider option enabled) Standalone Mode: 1 to 5 keys Technology: Patented spread-spectrum QTouchADC charge-transfer Number of Output Lines: Comms Mode: Up to 10 channels can be configured as outputs (but they will replace the keys) Standalone Mode: 1 to 5 channels can be configured as outputs Key Outline Sizes: QTouch 5 mm x 5 mm or larger (panel thickness dependent) Key Spacings: 12-channel 6 mm or wider, center to center (panel thickness, human factors dependent) Key Design: Touch Sensor Single solid or ring shaped electrodes widely different sizes and shapes possible Proximity Electrode Design: IC Single solid electrodes Key Design, Loop, PCB Trace - different sizes and shapes possible Wheel Size: Typically 30 mm 50 mm diameter AT42QT2120 Wheel Electrode Design: Spatially interpolated wheel up to 80 mm diameter Typical width of segments 12 mm Slider Electrode Design: Spatially interpolated, resistorless design Typical length 50 mm 100 mm, typical width 12 mm Can be an arc or other irregular shape Substrates: FR-4, low cost CEM-1 or FR-2 PCB materials polyamide FPCB PET films, glass Adjacent Metal: Compatible with grounded metal immediately next to keys Layers Required: One electrodes and components can be on same side Electrode Materials: Etched copper, silver, carbon, indium tin oxide (ITO), PEDOT Panel Materials: Plastic, glass, composites, painted surfaces (nonconductive paints) Key Panel Thickness: Up to 15 mm glass (key size dependent) Up to 10 mm plastic (key size dependent) Wheel/slider Panel Thickness: Up to 4 mm glass Up to 3 mm plastic Key Sensitivity: 2 Comms Mode individually settable via simple commands over I C interface Standalone mode settings are fixed Interface: 2 I C slave mode (400 kHz) CHANGE status indication pin Signal Processing: Self-calibration, Auto drift compensation, Noise filtering, Adjacent Key Suppression (AKS ) Power: 1.8 V to 5.5 V Packages: 20-pin SOIC/TSSOP RoHS compliant IC 9634EAT4206/12 20-pad VQFN RoHS compliant IC1. Pinouts and Schematics 1.1 Pinouts 1.1.1 20-pin SOIC/TSSOP Comms Mode KEY8/GPO6 1 20 KEY9/GPO7 KEY7/GPO5 2 19 KEY10/GPO8 KEY6/GPO4 3 18 KEY11/GPO9 KEY5/GPO3 4 17 CHANGE KEY4/GPO2 5 16 SCL QT2120 KEY3/GPO1 6 15 N/C KEY2/GPO0 7 14 RESET KEY1 8 13 SDA KEY0 9 12 MODE VSS 10 11 VDD 1.1.2 20-pin SOIC/TSSOP Standalone Mode OUT3 1 20 OUT4 OUT2 2 19 OUT5 KEY6 3 18 OUT6 KEY5 4 17 N/C KEY4 5 16 N/C QT2120 KEY3 6 15 PXOUT KEY2 7 14 RESET GUARD 8 13 N/C PROX 9 12 MODE VSS 10 11 VDD 2 AT42QT2120 9634EAT4206/12