Capacitive sensor offers low power

Available in a 20-lead QFN package, the MPR121 capacitive touch sensor provides reliable touch detection through increased electrode count (up to 12 touch electrodes). This part operates at 1.7 to 3.6 V and consumes 29 μA average supply current and 3 µA maximum shutdown current. The part requires only one external passive (no passives per channel).

Features include an independent auto-calibration and auto-configuration system, a hardware-configurable I2 C address, and separate touch and release trip thresholds for each electrode. It also features a 13th simulated electrode that represents the simultaneous charging of all of the electrodes connected together to allow for increased proximity detection in a touch panel or touch screen array. ($0.78 ea/10,000 — prod qty, Nov 2009.)

Freescale Semiconductor
Austin , TX
Sales 800-521-6274
http://www.freescale.com