Title:
CAPACITANCE MEASUREMENT CIRCUIT, TOUCH CONTROL CHIP, AND ELECTRONIC DEVICE
Document Type and Number:
WIPO Patent Application WO/2021/243532
Kind Code:
A1
Abstract:
A capacitance measurement circuit, a touch control chip, and an electronic device, which are able to effectively extract a capacitance change quantity and not increase circuit cost. The capacitance measurement circuit (300) comprises: a CCA circuit (310), where a first input terminal and a second input terminal of the CCA circuit (310) are respectively connected to a capacitor to be measured (331) and a cancellation capacitor (332), a third input terminal of the CCA circuit (310) is connected to a coding voltage, a first output terminal and a second output terminal of the CCA circuit (310) respectively output a first current and a second current, and the cancellation capacitor (332) is less than an initial value of the capacitor to be measured (331); and a PGA circuit (320), where two input terminals of the PGA circuit (320) are respectively connected to two output terminals of the CCA circuit (310); a proportion between the first current and the second current is set to be equal to a proportion between the initial value of the capacitor to be measured (331) and the cancellation capacitor (332), so that when the capacitor to be measured (331) is at the initial value, an output of the PGA circuit (320) is 0, and when the capacitor to be measured (331) changes relative to the initial value, the output of the PGA circuit (320) correlates to a capacitance change quantity of the capacitor to be measured (331).
Inventors:
YU QIAN (CN)
Application Number:
PCT/CN2020/093850
Publication Date:
December 09, 2021
Filing Date:
June 02, 2020
Export Citation:
Assignee:
SHENZHEN GOODIX TECH CO LTD (CN)
International Classes:
G06F3/041; G06F3/044
Foreign References:
| CN108064344A | 2018-05-22 | |||
| CN108475155A | 2018-08-31 | |||
| CN108124474A | 2018-06-05 | |||
| US20150338958A1 | 2015-11-26 | |||
| US20160034094A1 | 2016-02-04 |
Attorney, Agent or Firm:
LONGSUN LEAD IP LTD. (CN)
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