Patent ID: 11966531
Assignee: REALTEK SEMICONDUCTOR CORPORATION
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A capacitive sensing device, comprising:
an amplifier circuit, wherein a first input terminal of the amplifier circuit is coupled to a capacitor under-test;
a feedback capacitor coupled between the first input terminal and an output terminal of the amplifier circuit;
a switch circuitry configured to transmit a first reference voltage to a second input terminal of the amplifier circuit and couple the first input terminal to the output terminal during a first phase, transmit a second reference voltage to the second input terminal during a second phase, and adjust an output voltage of the output terminal during a third phase;
a counter circuit configured to start counting during the third phase and stop counting according to a control signal to generate a count value, wherein the count value indicates a capacitance value change of the capacitor under-test; and
a comparator circuit configured to generate the control signal according to the output voltage and the second reference voltage during the third phase.