Synaptics Incorporated
Method and system for alternative absolute profile determination

Abstract:

The invention relates to a processing system. The processing system includes a sensor module performing a first measurement to obtain a combination signal using a first sensor electrode and a second sensor electrode. The first electrode is driven using a first modulated signal with a first driving voltage amplitude and simultaneously the second electrode is driven using a second modulated signal with a second driving voltage amplitude greater than the first driving voltage amplitude, while simultaneously first and second resulting signals are received from the first and second electrodes, respectively. The sensor module is further performs a second measurement to obtain a transcapacitance signal using the first and second sensor electrodes. The processing system also includes a determination module that generates the combination signal by combining the first and second resulting signals, and computes an absolute capacitance signal from the combination signal, the transcapacitance signal, and a background capacitance.