Title:
CAPACITIVE DETECTION CIRCUIT, TOUCH DETECTION APPARATUS, AND TERMINAL DEVICE
Document Type and Number:
WIPO Patent Application WO/2019/183922
Kind Code:
A1
Abstract:
A capacitive detection circuit and a touch detection apparatus, being capable of improving sensitivity of capacitive detection. The capacitive detection circuit comprises a front-end circuit (210) and a processing circuit (220); the front-end circuit (210) comprises a first driving circuit (211), a first offset circuit (212), and a PGA circuit (213); the first driving circuit (211), the first offset circuit (212), and the PGA circuit (213) are connected to a first end of a capacitor to be detected; a second end of the capacitor to be detected is grounded; the first driving circuit (211) is configured to charge and discharge the capacitor to be detected; the first offset circuit (212) is configured to offset basic capacitance of the capacitor to be detected; the PGA circuit (213) is configured to convert a capacitance signal of the capacitor to be detected, of which the basic capacitance is offset, into a voltage signal; the processing circuit (220) is connected to an output end of the front-end circuit (210), and is configured to determine variation of capacitance of the capacitor to be detected with respect to the basic capacitance according to the voltage signal output by the front-end circuit (210).
Inventors:
YUAN GUANGKAI (CN)
JIANG HONG (CN)
LI GUOPAO (CN)
JIANG HONG (CN)
LI GUOPAO (CN)
Application Number:
PCT/CN2018/081331
Publication Date:
October 03, 2019
Filing Date:
March 30, 2018
Export Citation:
Assignee:
SHENZHEN WEITONGBO TECH CO LTD (CN)
International Classes:
G06F3/044
Foreign References:
| CN107820570A | 2018-03-20 | |||
| CN107192850A | 2017-09-22 | |||
| CN104199581A | 2014-12-10 | |||
| CN107560640A | 2018-01-09 |
Other References:
See also references of EP 3591507A4
Attorney, Agent or Firm:
LONGSUN LEAD IP LTD. (CN)
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