Patent ID: 9236861
Filing Date: 2016-01-12
CPC Classification: H03K

Claim Text:
1. A capacitive proximity sensing circuit, comprising: one or more guard electrodes; first capacitive sensor circuitry configured to sense a first capacitance and produce a first capacitive sensor reading responsive to the sensed first capacitance and indicative of detection of a user proximate to the first capacitive sensor, wherein the first capacitive sensor circuitry includes a first capacitive sensor coupled to a first side of at least one of the one or more guard electrodes; second capacitive sensor circuitry configured to sense a second capacitance and produce a second capacitive sensor reading responsive to the sensed second capacitance and indicative of detection of the user proximate to the second capacitive sensor, wherein the second capacitive sensor circuitry includes a second capacitive sensor coupled to a second side of at least one of the one or more guard electrodes; and output circuitry configured to receive and compare the first and second capacitive sensor readings and produce an output signal to indicate detection of the user proximate to the first capacitive sensor when the first capacitive sensor reading is greater than the second capacitive sensor reading.