Title:
HIGH-SENSITIVITY CAPACITIVE SENSOR CIRCUIT
Document Type and Number:
WIPO Patent Application WO/2019/027124
Kind Code:
A1
Abstract:
The present invention relates to a high-sensitivity capacitive sensor circuit which has improved sensitivity by implementing a plurality of detection units using charging and discharging. The capacitive sensor circuit of the present invention comprises: an oscillation unit for generating a control clock; a first charge/discharge unit connected to a sensor unit terminal so as to generate a sensing signal while being charged/discharged according to the control clock; a second charge/discharge unit connected in parallel to the first charge/discharge unit so as to generate a reference signal while being charged/discharged according to the control clock; and a detection unit for detecting a change in the capacitance on the side of the sensor unit terminal by comparing the sensing signal from the first charge/discharge unit with the reference signal from the second charge/discharge unit. The first charge/discharge unit comprises: a first capacitor which is connected at one end thereof to the sensor unit terminal and is charged/discharged according to the control clock; a first constant-current source for supplying a predetermined amount of constant-current to the first capacitor so as to charge the first capacitor; and a first switch for controlling the first capacitor such that, according to the control clock, the first capacitor is repetitively charged and discharged every half cycle of the clock. The second charge/discharge unit comprises: a second capacitor which is charged/discharged according to the control clock; a second constant-current source for supplying a predetermined amount of constant-current to the second capacitor so as to charge the second capacitor; and a second switch for controlling the second capacitor such that, according to the control clock, the second capacitor is repetitively charged and discharged every half cycle of the clock.
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Inventors:
SONG CHUNG DAM (KR)
Application Number:
PCT/KR2018/004480
Publication Date:
February 07, 2019
Filing Date:
April 18, 2018
Export Citation:
Assignee:
SONG CHUNG DAM (KR)
International Classes:
H03K17/955; H03K17/945
Foreign References:
| KR101046666B1 | 2011-07-06 | |||
| JPH0760185B2 | 1995-06-28 | |||
| US6456198B1 | 2002-09-24 | |||
| KR20100100773A | 2010-09-15 | |||
| KR20110134886A | 2011-12-15 |
Attorney, Agent or Firm:
SHIN WOO PATENT & LAW FIRM (KR)
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