公开(公告)号：US10976796B2

公开(公告)日：2021-04-13

申请号：US16040025

申请日：2018-07-19

Applicant: QUALCOMM Incorporated

Inventor： Rajesh Anantharaman ,  Ajay Taparia ,  Shunxi Wang

IPC: G06F3/044 ,  G06F3/041 ,  G06F3/047 ,  G06F1/32

Abstract: Aspects of the disclosure are directed to self-capacitance measurement and cancellation. In accordance with one aspect, a self-capacitance cancellation circuit includes an input amplifier, wherein the input amplifier comprises a non-inverting input, an inverting input and an output; a coherent current source coupled to the inverting input; a feedback network coupled to the output; and a capacitance coupled to the inverting input.

公开(公告)号：US09846186B2

公开(公告)日：2017-12-19

申请号：US14530889

申请日：2014-11-03

Applicant: Qualcomm Incorporated

Inventor： Ozan E. Erdogan ,  Guozhong Shen ,  Rajesh Anantharaman ,  Ajay Taparia ,  Behrooz Javid ,  Syed T. Mahmud ,  Rahim F. Chowdhury

IPC: G06F3/044 ,  G01R27/26 ,  G06F3/041

CPC classification number: G01R27/2605 ,  G06F3/0416 ,  G06F3/044

Abstract: An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform.

公开(公告)号：US20170205948A1

公开(公告)日：2017-07-20

申请号：US15476745

申请日：2017-03-31

Applicant: QUALCOMM Incorporated

Inventor： Ozan E. Erdogan ,  Guozhong Shen ,  Rajesh Anantharaman ,  Ajay Taparia ,  Behrooz Javid ,  Syed T. Mahmud ,  Rahim F. Chowdhury

IPC: G06F3/041 ,  G06F3/044 ,  G01R27/26

CPC classification number: G01R27/2605 ,  G06F3/0416 ,  G06F3/044

Abstract: An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform.

公开(公告)号：US09857932B2

公开(公告)日：2018-01-02

申请号：US15476745

申请日：2017-03-31

Applicant: QUALCOMM Incorporated

Inventor： Ozan E. Erdogan ,  Guozhong Shen ,  Rajesh Anantharaman ,  Ajay Taparia ,  Behrooz Javid ,  Syed T. Mahmud ,  Rahim F. Chowdhury

IPC: G06F3/044 ,  G06F3/041 ,  G01R27/26

CPC classification number: G01R27/2605 ,  G06F3/0416 ,  G06F3/044

Abstract: An analog front end circuit utilizes coherent detection within a capacitance measurement application. The analog front end circuit uses coherent detection to measure capacitance of a touch screen display. An analog excitation signal is modulated by a capacitor to be measured. The modulated signal is synchronously demodulated using a correlator, which includes a discrete mixer and a discrete integrator. The excitation signal is also input to the mixer such that the modulated signal is multiplied by the excitation signal. The excitation signal is an analog signal having a sine wave function or other waveform.