Title:
CAPACITANCE MEASUREMENT CIRCUIT
Document Type and Number:
WIPO Patent Application WO/2022/033466
Kind Code:
A1
Abstract:
Disclosed is a capacitance measurement circuit, comprising an analog front-stage circuit, a parasitic capacitor, an ADC module, an output shift register, and a controller. M parallel current mirror circuits are arranged in the analog front-stage circuit. The controller first disconnects a capacitor to be measured, only connects one current mirror circuit, records, by means of charging of the parasitic capacitor and outputting of the analog front-stage circuit, an AFE output voltage VN collected at an inverting input end of the ADC module, then connects the capacitor to be measured, collects an AFE output voltage VP at a non-inverting input end of the ADC module, and converts the value of (VP-VN) into a first digital signal; determines the number m of the connected current mirror circuits according to the value of the first digital signal, controls the analog front-stage circuit to be connected to the m current mirror circuits, and repeats the described steps to obtain a second digital signal; and finally, performs shift processing on the second digital signal according to said number m to obtain a capacitance measurement value of the capacitor to be measured. The use of the technical solution of the present invention can reduce the measurement error and improve the measurement precision.
Inventors:
ZENG YANHAN (CN)
ZHI HAOCHANG (CN)
CHEN YONGNAN (CN)
CHEN JUNKAI (CN)
YANG JINGCI (CN)
WU TIANXIAN (CN)
ZHI HAOCHANG (CN)
CHEN YONGNAN (CN)
CHEN JUNKAI (CN)
YANG JINGCI (CN)
WU TIANXIAN (CN)
Application Number:
PCT/CN2021/111758
Publication Date:
February 17, 2022
Filing Date:
August 10, 2021
Export Citation:
Assignee:
UNIV GUANGZHOU (CN)
International Classes:
G01R27/26
Foreign References:
| CN111999565A | 2020-11-27 | |||
| CN106556747A | 2017-04-05 | |||
| CN101666830A | 2010-03-10 | |||
| CN101738544A | 2010-06-16 | |||
| CN108918980A | 2018-11-30 | |||
| US20180172744A1 | 2018-06-21 | |||
| US20190257870A1 | 2019-08-22 |
Attorney, Agent or Firm:
GUANGZHOU HUAXUE INTELLECTUAL PROPERTY AGENCY CO., LTD. (CN)
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