Synaptics Incorporated
DEVICE AND METHOD FOR CAPACITIVE SENSING

Abstract:

A semiconductor device comprises driver circuitry, an analog-digital (AD) converter, and processing circuitry. The driver circuitry is configured to supply a drive signal to a sensor array in a sensing frame comprising 2N bursts, N being an integer of two or more. The mixer circuitry is configured to modulate a plurality of carrier waves with a plurality of sensing signals corresponding to capacitances of a plurality of sensing electrodes of the sensor array, respectively, to output a plurality of mixer outputs. A number of the plurality of sensing electrodes is 2N-1 or 2N. The AD converter is configured to perform AD conversion on a sum signal of the plurality of mixer outputs. The processing circuitry is configured to detect an object based on the output of the AD converter.