Capacitive-Touch IC Includes Power Management

The QT102, a single-channel touch-on/touch-off sensor chip also integrates power management and safety functionality, making it suitable for use in products with rigid power-management requirements. In a SOT-23 package, the chip combines a toggle mode on/off switch with a hardware-programmable, auto-switch-off/override/reset capability. It also provides immediate shut-off in case of a system malfunction. Power management control, running mostly in low-power mode, temporarily switches to high-power mode once a touch is detected. This guarantees a typical consumption of 37 µA at 3V while maintaining a fast touch response. Additional features include automatic recalibration and a detect integrator that suppresses detection generated by electrical noise or unintentional contact. A user-configurable output pin allows for interfacing to a host MCU or to drive power loads via a MOSFET or bipolar transistor. Price is less than $0.50 each in high volume. SAELIG CO., Pittsford, NY. (888) 772-3544.