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Patent Searching and Data


Title:
CONSTANT CURRENT CIRCUIT FOR SENSOR, AND CAPACITANCE DETECTION DEVICE USING SAME
Document Type and Number:
WIPO Patent Application WO/2021/101197
Kind Code:
A1
Abstract:
Disclosed in one embodiment of the present invention is a constant current circuit for forming a constant drain current of an FET for capacitance detection of a capacitive sensor, and a capacitance detection device using same. The disclosed constant current circuit comprises: a reference FET; a sawtooth waveform voltage generation unit for applying a sawtooth waveform voltage of a predetermined clock cycle to the gate of the reference FET; a smoothing circuit connected between a Vcc and the drain of the reference FET so as to apply a smoothed voltage; a current mirror for supplying a constant current to the sawtooth waveform voltage generation unit, and causing the drain current of the reference FET to be constant; and a comparator, which compares the drain voltage of the reference FET with a predetermined reference voltage so as to feed same back to the current mirror.

Inventors:
SONG CHUNG DAM (KR)
Application Number:
PCT/KR2020/016131
Publication Date:
May 27, 2021
Filing Date:
November 17, 2020
Export Citation:
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Assignee:
SONG CHUNG DAM (KR)
International Classes:
G05F3/22; G05F3/26; H03K17/96
Domestic Patent References:
WO2012176746A12012-12-27
Foreign References:
KR20190101217A2019-08-30
JP2010044470A2010-02-25
KR20190101218A2019-08-30
KR20100062217A2010-06-10
Attorney, Agent or Firm:
SHINWOO PATENT & LAW FIRM (Teheran-ro 21-gilGangnam-gu, Seoul, KR)
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