CPC H03K 17/962 (2013.01) [G01R 27/2605 (2013.01); G06F 3/044 (2013.01); H01L 28/60 (2013.01); H03K 17/955 (2013.01); H03K 2017/9602 (2013.01)] | 20 Claims |
1. A system, comprising:
a housing having an outer surface and an inner surface, the inner surface defining an internal volume;
a sensing electrode disposed within the housing;
a connecting electrode disposed on the inner surface within the internal volume; and
a capacitive sensing circuit galvanically connected to the connecting electrode at a first port, but not to the sensing electrode, the capacitive sensing circuit configured to:
determine a first capacitance between the first port and a ground, the first capacitance including a variable capacitance between the connecting electrode and a person when the person is touching the housing;
determine a second capacitance between the first port and the ground associated with a time when the person is not touching the housing; and
determine a difference between the second capacitance and the first capacitance.
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