CAPACITIVE SENSING SLIDE DETECTION

摘要

A circuit includes a first capacitor (18) having first and second capacitive sensing strips positioned on first and second sliding portions of the slider type mobile device. In the closed position, the first and second capacitive sensing strips overlap one another and in an open position the first and second capacitive sensing strips have no overlap with one another. A voltage divider (R1, R2) having a voltage VIN(+) comprised of a first resistor network is coupled with the first capacitor (18). A voltage comparator (62) having two inputs VIN(+) and VIN(-) is used to determine a high or low state. A second resistive network (R3, R4) is used to set VIN(-). The voltage comparator (62) will return a digital high condition indicative of the slider being in the open position when VIN(+) is greater than VIN(-) and a digital low condition indicative of the slider being in the closed position when VIN(+) is less than VIN(-).