公开(公告)号：US11824549B2

公开(公告)日：2023-11-21

申请号：US17494494

申请日：2021-10-05

Applicant: SHENZHEN GOODIX TECHNOLOGY CO., LTD.

Inventor： Junxi Chen ,  Zhengfeng Wang

IPC: H03M1/08 ,  H03F3/45 ,  H03M1/80 ,  H03M1/46 ,  G05F1/575 ,  G05F1/595 ,  H03F3/50 ,  H03M1/38

CPC classification number: H03M1/0863 ,  G05F1/575 ,  G05F1/595 ,  H03F3/45475 ,  H03F3/505 ,  H03M1/46 ,  H03M1/804 ,  H03M1/38

Abstract: A reference voltage buffer circuit is provided, which could improve the reliability of the reference voltage buffer circuit, including: at least one output branch, where each output branch includes a delay control branch, a first MOSFET, and a second MOSFET; and a feedback branch, where in a first time period, the feedback branch is configured to output a first voltage to the delay control branch, and the delay control branch is configured to control the first MOSFET and the second MOSFET to be turned on, such that a source of the first MOSFET continuously outputs a reference voltage; and in a second time period, a voltage output from the feedback branch to the delay control branch is 0, the delay control branch is configured to control the second MOSFET to be turned off before the first MOSFET is turned off.

公开(公告)号：US10921938B2

公开(公告)日：2021-02-16

申请号：US16420146

申请日：2019-05-22

Applicant: SHENZHEN GOODIX TECHNOLOGY CO., LTD.

Inventor： Zhengfeng Wang ,  Shuo Fan

IPC: G06F3/044 ,  G06F3/041 ,  H03K17/96

Abstract: A capacitance detecting circuit, includes a first front end circuit, a second front end circuit, a control circuit and a processing circuit, wherein the control circuit controls the first front end circuit and the second front end circuit such that the first front end circuit is configured to convert a capacitance signal of a detection capacitor into a first voltage signal through a first calibration capacitor, and the second front end circuit is configured to convert a capacitance signal of the detection capacitor into a second voltage signal through a second calibration capacitor; the processing circuit is calculates a differential signal of the first voltage signal and the second voltage signal to determine a capacitance variation of the detection capacitor according to the differential signal.