Synaptics Incorporated
Display device having an integrated sensing device with reduced interference

Abstract:

A processing system for an input device comprises drive circuitry configured to generate a fixed voltage for a common voltage electrode of the input device during a display update period, and generate a sensing signal for the common voltage electrode during an input sensing period, the sensing signal having a duty cycle and a mean value, wherein the duty cycle minimizes a difference between the fixed voltage and the mean value. An input device comprises one or more common voltage electrodes and a coupled processing system. The processing system is configured to drive the one or more common voltage electrodes with a fixed voltage during a display update period, and a sensing signal during an input sensing period. The sensing signal has a duty cycle and a mean value, the duty cycle configured to minimize a difference between the mean value and the fixed voltage.