Synaptics Incorporated
SYSTEM AND METHOD FOR REDUCING ELECTROMAGNETIC INTERFERENCE

Abstract:

A system and method for reducing electromagnetic interference comprises generating a first voltage signal based on a settling time of a first electrode, a slew rate of a signal generator, and a harmonic parameter, and driving the first electrode with the first voltage signal. The first voltage signal may be one of a capacitive sensing signal, display update signal, a transmission signal, and a selection signal. Further, a processing system may be configured to operate in one of an absolute capacitive sensing mode and a transcapacitive sensing mode. In an absolute capacitive sensing mode, the processing system is configured to receive a resulting signal with the first electrode, and determine a measurement of a change in capacitive coupling of the first electrode based on the resulting signal. In a transcapacitive sensing mode, the processing system is configured to receive a resulting signal with a second electrode, and determining a measurement of a change in a capacitive coupling between the first electrode and the second electrode based on the resulting signal.