公开(公告)号：US10277244B1

公开(公告)日：2019-04-30

申请号：US16046053

申请日：2018-07-26

Applicant: QUALCOMM Incorporated

Inventor： Ankit Srivastava ,  Sameer Wadhwa ,  Shunxi Wang

IPC: H03M1/38 ,  H03M1/46 ,  H03G3/30

Abstract: Certain aspects of the present disclosure provide a successive approximation register (SAR) analog-to-digital converter (ADC) implemented with a passive gain scaling architecture. Certain aspects provide a circuit for analog-to-digital conversion. The circuit generally includes a plurality of capacitive elements, a plurality of switches coupled to the plurality of capacitive elements, and SAR logic having an output coupled to control inputs of the plurality of switches. The circuit also includes a comparator having an output coupled to an input of the SAR logic, a sampling circuit coupled to an input node of the circuit, and a first capacitive element coupled in series between the sampling circuit and the plurality of capacitive elements.

公开(公告)号：US20190294295A1

公开(公告)日：2019-09-26

申请号：US15926728

申请日：2018-03-20

Applicant: QUALCOMM Incorporated

Inventor： Zongyu Dong ,  Sameer Wadhwa ,  Shunxi Wang

IPC: G06F3/041 ,  H03F3/21 ,  H03F3/45 ,  H03F3/213 ,  H03F1/02 ,  G06F3/044

Abstract: A touchscreen controller includes a set of transmitters for generating transmit signals applied to electrically-conductive transmit lines of a touchscreen panel, and a set of receivers configured to receive the signals via electrically-conductive receive lines that are capacitively coupled to the transmit lines. Each receiver includes an integrator to integrate the received current signal to generate an output voltage used for determining a location, if any, of a finger or object touching the panel. The integrator includes input and output amplification stages, and a feedback capacitor coupled between an input and output of the cascaded amplification stages. The capacitance of the feedback capacitor is configured so that the integrator achieves a desired rejection of a received jammer current signal. To reduce the size of the feedback capacitor, a bypass amplification stage is provided to steer away some of the input jammer current from the input of the integrator.

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.