Patent ID: 9459298
Filing Date: 2016-10-04
CPC Classification: G01D,G01N,G01R

Claim Text:
1. A capacitance sensing device comprising: a signal generator that generates both a digital local oscillator (LO) signal and an excitation signal; a capacitance-to-amplitude converter (C2A) coupled to the signal generator, the C2A converts a measured capacitance to an AC signal having an amplitude proportional to the measured capacitance; a demodulator coupled to receive the AC signal from the C2A and the digital LO signal from the signal generator, the demodulator multiplies the AC signal with the digital LO signal to generate a DC signal proportional to the amplitude; and an analog-to-digital converter (ADC) coupled to the output of the demodulator, the ADC outputs a digital conversion value proportional to both the DC component and the measured capacitance.