摘要 |
A proximity sensor includes a sense electrode having a first capacitance to ground, wherein the first capacitance varies in response to proximity of an object to be sensed; a first sense circuit which provides a first pulse signal having a pulse width determined in accordance with the first capacitance; a reference capacitor; a second sense circuit which provides a second pulse signal having a pulse width determined in accordance with a second capacitance of the reference capacitor; and a computing circuit which computes a difference pulse by subtracting the second pulse signal from the first pulse signal and provide a pulse of the difference pulse width.
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