STMicroelectronics QST108: Capacitive touch sensor features a single-chip control interface

Providing an intelligent single-chip-controller interface responding to a user’s touch, the QST108 capacitive touch sensor allows users to create capacitive touch panels with as many as eight keys for product-user interfaces using conventional or flexible PCBs (printed-circuit-board). Sense electrodes provide the option of PCB-layout integration or printing using conductive ink with flexibility in electrode sizes and shapes. An electrode behind a nonconductive front panel made of glass or plastic allows detection of a finger touch. Required external components include one sampling capacitor and one resistor per channel. Driving as many as eight LEDs, the sensor features PWM (pulse-width-modulation) capabilities for driving a beeper output or controlling LED brightness. Debounced touch-detection results are accessible using individual outputs or through the I²C interface. Available in an LQFP-32 package, the QST108 costs $1.08 (10,000)

STMicroelectronics, www.st.com