公开(公告)号：US10649015B1

公开(公告)日：2020-05-12

申请号：US15943154

申请日：2018-04-02

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Vikrant Arumugam ,  Amar Vellanki ,  Vamsikrishna Parupalli ,  Zhong You ,  Johann G. Gaboriau ,  John L. Melanson

IPC: G01R27/26

Abstract: A method may include applying an excitation signal to a capacitor of the capacitive sensor which causes generation of a modulated signal from an input signal indicative of a variance in a capacitance of the capacitor, detecting the modulated signal with a detector to generate a detected modulated signal that has a phase shift relative to the excitation signal, demodulating the detected modulated signal into an in-phase component and a quadrature component using a reference signal, nullifying the quadrature component by setting a phase of the reference signal relative to the excitation signal to compensate for the phase shift, and outputting the in-phase component as an unmodulated output signal representative of the capacitance.

公开(公告)号：US11119138B1

公开(公告)日：2021-09-14

申请号：US16838405

申请日：2020-04-02

Applicant: Cirrus Logic International Semiconductor Ltd.

Inventor： Vikrant Arumugam ,  Amar Vellanki ,  Vamsikrishna Parupalli ,  Zhong You ,  Johann G. Gaboriau ,  John L. Melanson

IPC: G01R27/26

Abstract: A method may include applying an excitation signal to a capacitor of the capacitive sensor which causes generation of a modulated signal from an input signal indicative of a variance in a capacitance of the capacitor, detecting the modulated signal with a detector to generate a detected modulated signal that has a phase shift relative to the excitation signal, demodulating the detected modulated signal into an in-phase component and a quadrature component using a reference signal, nullifying the quadrature component by setting a phase of the reference signal relative to the excitation signal to compensate for the phase shift, and outputting the in-phase component as an unmodulated output signal representative of the capacitance.