Title:
FINGERPRINT DETECTION AMPLIFICATION CIRCUIT AND FINGERPRINT IDENTIFICATION DEVICE
Document Type and Number:
WIPO Patent Application WO/2023/160391
Kind Code:
A1
Abstract:
Provided are a fingerprint detection amplification circuit (20a) and a fingerprint identification device. The fingerprint detection amplification circuit (20a) comprises a fully differential amplifier (21), a switch group (23), a first feedback circuit (25a), and a second feedback circuit (27a). The switch group controls a first input end (211) and a second input end (213) of the fully differential amplifier to be electrically connected to a sensing electrode alternately. The first feedback circuit (25a) converts a capacitance value of a sensing capacitor inputted to the first input end (211) into a voltage signal. The second feedback circuit (27a) converts a capacitance value of the sensing capacitor inputted to the second input end (213) into a voltage signal. A signal in the fingerprint detection amplification circuit works in a specified voltage domain. A low level signal in the specified voltage domain is a floating signal. The low level signal is switched between a first low voltage and a second low voltage. When the low level signal is switched between the first low voltage and the second low voltage, a first output end (VOUTP) and a second output end (VOUTN) of the fully differential amplifier alternately output; and the voltage of the first output end (VOUTP) and the voltage of the second output end (VOUTN) have a common-mode voltage.
Inventors:
JIANG XINXI (CN)
CHENG ZHENJUAN (CN)
SUN TIANQI (CN)
ZHANG JINGKAI (CN)
CHENG ZHENJUAN (CN)
SUN TIANQI (CN)
ZHANG JINGKAI (CN)
Application Number:
PCT/CN2023/074960
Publication Date:
August 31, 2023
Filing Date:
February 08, 2023
Export Citation:
Assignee:
FOCALTECH ELECTRONICS SHENZHEN CO LTD (CN)
International Classes:
G06V40/13; H03F3/45
Foreign References:
| CN114627514A | 2022-06-14 | |||
| CN110363184A | 2019-10-22 | |||
| CN110598515A | 2019-12-20 | |||
| US20200161493A1 | 2020-05-21 | |||
| CN110390317A | 2019-10-29 | |||
| CN113922776A | 2022-01-11 | |||
| US20200343864A1 | 2020-10-29 | |||
| CN112016378A | 2020-12-01 |
Other References:
JIANG, PEILIANG ET AL.: "Discussion on Pressure Sensor based on Plantar Pressure Information Collection", ZHONGGUO GAO-XIN JISHU QIYE = CHINA HIGH TECHNOLOGY ENTERPRISES, ZHONGGUO GAO-XIN JISHU QIYE FAZHAN PINGJIA ZHONGXIN, CN, no. 15, 20 May 2015 (2015-05-20), CN , pages 66 - 67, XP009548886, ISSN: 1009-2374, DOI: 10.13535/j.cnki.11-4406/n.2015.15.034
Attorney, Agent or Firm:
SHENZHEN SCIENBIZIP INTELLECTUAL PROPERTY AGENCY CO., LTD. (CN)
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