Invention Grant
- Patent Title: Capacitive sensing device
-
Application No.: US14783810Application Date: 2014-04-02
-
Publication No.: US09726775B2Publication Date: 2017-08-08
- Inventor: Laurent Lamesch
- Applicant: IEE INTERNATIONAL ELECTRONICS & ENGINEERING S.A.
- Applicant Address: LU Echternach
- Assignee: IEE International Electronics & Engineering S.A.
- Current Assignee: IEE International Electronics & Engineering S.A.
- Current Assignee Address: LU Echternach
- Agency: Reising Ethington P.C.
- Priority: LU92179 20130409
- International Application: PCT/EP2014/056552 WO 20140402
- International Announcement: WO2014/166780 WO 20141016
- Main IPC: G01V3/08
- IPC: G01V3/08 ; H03K17/955 ; G01D5/24 ; H03K17/00 ; E05F15/73 ; B60N2/00 ; B60N2/56 ; B62D1/06

Abstract:
A capacitive sensing device includes an antenna electrode for emitting an alternating electric field in response to an alternating voltage caused in the antenna electrode and a control and evaluation circuit that includes a transimpedance amplifier configured to maintain the alternating voltage equal to an alternating reference voltage on a reference voltage node by injecting a current into the antenna electrode and to measure the current. The control and evaluation circuit includes a microcontroller and a multiplexer configured and arranged to switch the antenna electrode alternately to a current input of the transimpedance amplifier and to the alternating reference voltage node. The microcontroller is configured to control the multiplexer. The multiplexer and the transimpedance amplifier and a low-pass filter operatively connected to the transimpedance amplifier form together a synchronous rectifier arrangement. The current input node of the transimpedance amplifier is AC-coupled to the reference voltage node by a protection capacitor.
Public/Granted literature
- US20160306061A1 CAPACITIVE SENSING DEVICE Public/Granted day:2016-10-20
Information query