Capacitive voltage information sensing circuit and related anti-noise touch circuit

摘要

The present disclosure provides a capacitor voltage information sensing circuit. The capacitor voltage information sensing circuit includes a mixer and an analog filter. The mixer includes a first input terminal for receiving a reference signal, a second input terminal for receiving a voltage signal, the voltage signal includes capacitor voltage information and a noise when a touch occurs, a first output terminal for outputting a first differential signal according to the voltage signal and the reference signal, and a second output terminal for outputting a second differential signal according to the voltage signal and the reference signal. The analog filter is coupled to the mixer for generating a first low-frequency signal and a second low-frequency signal according to the first differential signal and second differential signal.

主权项

1. A capacitor voltage information sensing circuit, comprising:
a mixer, comprising:
a first input terminal, configured to receive a reference signal;a second input terminal, configured to receive a voltage signal, wherein the voltage signal comprises a capacitor voltage information and a noise when a touch occurs;a first output terminal, configured to output a first differential signal according to the voltage signal and the reference signal; anda second output terminal, configured to output a second differential signal according to the voltage signal and the reference signal; and an analog filter, coupled to the mixer, configured to generate a first low-frequency signal and a second low-frequency signal according to the first differential signal and the second differential signal; wherein the mixer outputs the first differential signal as the voltage signal and outputs the second differential signal as the reference signal during a first period, and the mixer outputs the first differential signal as the reference signal and outputs the second differential signal as the voltage signal during a second period; wherein the capacitor voltage information sensing circuit obtains the capacitor voltage information according to the first low-frequency signal and the second low-frequency signal.