CONFIGURABLE ANALOG FRONT-END FOR MUTUAL CAPACITANCE SENSING AND SELF CAPACITANCE SENSING

摘要

Capacitance sensing circuits and methods are provided. A dual mode capacitance sensing circuit includes a capacitance-to-voltage converter having an amplifier and an integration capacitance coupled between an output and an inverting input of the amplifier, and a dual mode switching circuit responsive to mutual mode control signals for a controlling signal supplied from a capacitive touch matrix to the capacitance-to-voltage converter in a mutual capacitance sensing mode and responsive to self mode control signals for controlling signals supplied from the capacitive touch matrix to the capacitance-to-voltage converter in a self capacitance sensing mode, wherein the capacitance sensing circuit is configurable for operation in the mutual capacitance sensing mode or the self capacitance sensing mode.