Synaptics Incorporated
Device and method for capacitive sensing with noise mitigation

Abstract:

A semiconductor device comprises first mixer circuitry and processing circuitry. The first mixer circuitry is configured to generate a plurality of first mixer outputs through quadrature decomposition of a sensing signal. The first sensing signal corresponds to a capacitance of a first sensing electrode supplied with a drive signal. The quadrature decomposition is based on an in-phase local carrier which is in phase with the drive signal and an out-of-phase local carrier having a phase different from that of the in-phase local carrier. The plurality of first mixer outputs comprises an in-phase mixer output generated based on the in-phase local carrier and the sensing signal, and an out-of-phase mixer output generated based on the out-of-phase local carrier and the sensing signal.