Invention Grant
- Patent Title: Capacitive charge measurement
- Patent Title (中): 电容电荷测量
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Application No.: US13436688Application Date: 2012-03-30
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Publication No.: US09274643B2Publication Date: 2016-03-01
- Inventor: Kirk Hargreaves
- Applicant: Kirk Hargreaves
- Applicant Address: US CA San Jose
- Assignee: Synaptics Incorporated
- Current Assignee: Synaptics Incorporated
- Current Assignee Address: US CA San Jose
- Main IPC: G01R27/26
- IPC: G01R27/26 ; G06F19/00 ; G06F3/041 ; G06F3/044 ; H03K17/96 ; G01R29/24

Abstract:
A circuit for measuring a capacitive charge comprises a latched comparator and a determination module. The latched comparator comprises an input and an output. The input is coupled with a sensor electrode of a capacitive input device. An inverted version of the output is coupled with a feedback loop. The feedback loop is configured to provide feedback to the input to maintain the input at a predetermined voltage. The feedback is provided in clocked charge quanta steps based on a clock signal. The determination module is coupled with the output and configured to determine a change in capacitance on the sensor electrode by equating output signals from the output with an amount of charge provided to the input to reach the predetermined voltage.
Public/Granted literature
- US20130262004A1 CAPACITIVE CHARGE MEASUREMENT Public/Granted day:2013-10-03
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