Atmel AT42QT2160 16-key QMatrix Touch Sensor IC DATASHEET Features Number of keys: up to 16 keys, and one slider (constructed from 2 to 8 keys) Technology: patented spread-spectrum charge-transfer (transverse mode) Number of I/O lines: 11 (3 dedicated configurable for input or output, 8 shared output only) PWM control for LED driving Key outline sizes: 6 mm 6 mm or larger (panel thickness dependent) widely different sizes and shapes possible Key spacings: 8 mm or wider, center to center (panel thickness dependent) Slider design: 2 to 8 keys placed in sequence, same design as keys Electrode design: two-part electrode shapes (drive-receive) wide variety of possible layouts PCB layers required: one layer (with jumpers), two layers (no jumpers) Electrode materials: PCB, FPCB, silver or carbon on film, ITO on film Panel materials: plastic, glass, composites, painted surfaces (low particle density metallic paints possible) Adjacent metal: compatible with grounded metal immediately next to keys Panel thickness: up to 3 mm glass, 2.5 mm plastic (key size dependent) Key sensitivity: 2 individually settable via simple commands over I C-compatible interface Interface: 2 I C-compatible slave mode (100 kHz) Moisture tolerance: Increased moisture tolerance based on hardware design and firmware tuning Signal processing: self-calibration, auto drift compensation, noise filtering Adjacent Key Suppression (AKS ) technology Applications: Laptop, mobile, consumer appliances, PC peripheral This datasheet is applicable to revision 4R0 chips only Operating Voltage: 1.8 V 5.5 V Package: 28-pin 4 4 mm QFN RoHS compliant 9502CAT4209/20141. Pinout and Schematic 1.1 Pinout Configuration 28 27 26 25 24 23 22 GPIO2 1 21 I2CA0 2 20 Y1B GPIO3 VDD 3 19 Y0B VSS 4 QT2160 18 VSS 5 17 X6 VDD 6 16 X7 VDD 7 15 X5 CHANGE 8 9 10 11 12 13 14 1.2 Pinout Descriptions Table 1-1. Pin Listing If Unused, Connect Pin Name Type Comments To 1 GPIO2 I/O General purpose input/output 2 2 GPIO3 I/O General purpose input/output 3 3 Vdd P Power 4 Vss P Supply ground 5 X6 O X matrix drive line / shared GPO X6 Leave open 6 X7 O X matrix drive line / shared GPO X7 Leave open 7 CHANGE OD State change notification Leave open 8 Vref P Supply ground 9 SMP O Sample output. 10 X0 O X matrix drive line / shared GPO X0 Leave open 11 X1 O X matrix drive line / shared GPO X1 Leave open AT42QT2160 DATASHEET 2 9502CAT4209/2014 VREF GPIO1 SMP Y1A Y0A X0 X1 RST X2 SCL X3 SDA X4 I2CA1