Microchip Technology Incorporated
Method And System For Touchless Gesture Detection And Hover And Touch Detection

Abstract:

A sensor system combining first and second detection systems supplies drive signals to nodes A and B electrodes of these systems. A drive sequence consists of a repetition of an elementary acquisition cycle having two consecutive main phases with pre-charge and acquisition phases. During a first pre-charge phase, node A is driven to a first electrical potential for and during a first acquisition phase, to a first intermediate electrical potential, and node B is driven to a second electrical potential and thereafter switches node B into high-impedance at DC, and during a second pre-charge phase, node A is driven to a third electrical potential and, during a second acquisition phase, to a second intermediate electrical potential, and node B is driven to a fourth potential and thereafter switches node B into high-impedance at DC. The first and second detection systems perform an electrical measurement on node A and B, respectively.