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US 2024/0393142 A1Published application
Capacitor sensing
AssigneeNXP USA, Inc.
InventorVaclav Bajgar
Life of this patent
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Abstract
As disclosed herein, circuitry and a method for providing a digitized voltage value of one capacitive sensor in which a second capacitive sensor is utilized for charge equalization. After charge equalization, an analog to digital converter (ADC) provides a digital value representative of the voltage of the one sensor.
Claims8
1-14. (canceled)
A circuit comprising:
- a plurality of external terminals;
- a plurality of switch circuits;
- at least one analog to digital converter;
- control circuitry for configuring the circuit to perform a capacitive sensing routine for sensing capacitive sensors coupled to the plurality of external terminals, the control circuitry configured to, during a precharge phase, control a first switch circuit of the plurality of switch circuits to charge a first external terminal of the plurality of external terminals to a first voltage and control a second switch circuit of the plurality of switch circuits to charge a second external terminal of the plurality of external terminals to a second voltage, the first voltage is different from the second voltage, after the charging, to control the first switch circuit to remove the first voltage from the first external terminal and control the second switch circuit to remove the second voltage from the second external terminal so that a capacitive sensor coupled to the first external terminal can equalize charge with a capacitive sensor coupled to the second external terminal, and after the equalization, to control to provide a digital indication of a sensed voltage level of the first external terminal by an analog to digital converter of the at least one analog to digital converter.
1 more element
Dependencies are inferred from the claim text.