Atmel AT42QT1040 Four-key QTouch Touch Sensor IC DATASHEET Features Number of QTouch Keys: Up to four Discrete Outputs: Four discrete outputs indicating individual key touch Technology: Patented spread-spectrum charge-transfer (direct mode) Electrode Design: Simple self-capacitance style (refer to the Touch Sensors Design Guide) 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 10 mm glass, 5 mm plastic (electrode size dependent) Key Sensitivity: Fixed key threshold, sensitivity adjusted via sample capacitor value Adjacent Key Suppression Patented Adjacent Key Suppression (AKS ) technology to enable accurate key detection Interface: Pin-per-key outputs, plus debug mode to observe sensor signals Moisture Tolerance: Increased moisture tolerance based on hardware design and firmware tuning Signal Processing: Self-calibration, auto drift compensation, noise filtering Applications: Mobile, consumer, white goods, toys, kiosks, POS, and so on Power: 1.8V 5.5 V Package: 20-pin 3 x 3 mm VQFN RoHS compliant 9524DAT4205/20131. Pinout and Schematic 1.1 Pinout Configuration 18 20 19 17 16 15 SNSK3 SNS2 1 OUT2 2 14 SNSK1 13 OUT3 SNS1 3 QT1040 12 SNSK0 4 OUT1 OUT0 11 SNS0 5 6 7 8 9 10 AT42QT1040 DATASHEET 2 9524DAT4205/2013 SNSK2 NC NC NC VSS NC NC VDD SNS3 NC