Invention Grant
- Patent Title: Arrangement to calibrate a capacitive sensor interface
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Application No.: US16491705Application Date: 2018-03-07
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Publication No.: US11112276B2Publication Date: 2021-09-07
- Inventor: Colin Steele , Rene Scheuner , Thomas Christen , Mark Niederberger
- Applicant: Knowles Electronics, LLC
- Applicant Address: US IL Itasca
- Assignee: Knowles Electronics, LLC
- Current Assignee: Knowles Electronics, LLC
- Current Assignee Address: US IL Itasca
- Agency: Foley & Lardner LLP
- Priority: EP17162320 20170322
- International Application: PCT/EP2018/055594 WO 20180307
- International Announcement: WO2018/172076 WO 20180927
- Main IPC: G01R27/26
- IPC: G01R27/26 ; G01D5/24 ; G01D18/00

Abstract:
An arrangement (2) to calibrate a capacitive sensor interface (1) includes a capacitive sensor (10) having a capacitance (cmem, cmemsp, cmemsm) and a charge storing circuit (20) having a changeable capacitance (cdum, cdump, cdumm). A test circuit (30) applies a test signal (vtst) to the capacitive sensor (10) and the charge storing circuit (20). An amplifier circuit (40) has a first input connection (E40a) coupled to the capacitive sensor (10) and a second input connection (E40b) coupled to the charge storing circuit (20). The amplifier circuit (40) provides an output signal (Vout) in dependence on a first input signal (ΔVerr1) applied to the first input connection (E40a) and a second input signal (ΔVerr2) applied to the second input connection (E40b). A control circuit (60) is configured to trim the capacitance (cdum, cdump, cdumm) of the charge storing circuit (20) such that the level of the output signal (Vout) tends to the level of zero.
Public/Granted literature
- US20200249052A1 ARRANGEMENT TO CALIBRATE A CAPACITIVE SENSOR INTERFACE Public/Granted day:2020-08-06
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