US 11,863,173 B2
Capacitive coupling for connection of remotely placed capacitive sensing electrodes
Peter Spevak, Moosburg an der Isar (DE)
Assigned to TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed by TEXAS INSTRUMENTS INCORPORATED, Dallas, TX (US)
Filed on Aug. 19, 2019, as Appl. No. 16/543,874.
Claims priority of provisional application 62/719,843, filed on Aug. 20, 2018.
Prior Publication US 2020/0059231 A1, Feb. 20, 2020
Int. Cl. H03K 17/96 (2006.01); G06F 3/044 (2006.01); H03K 17/955 (2006.01); G01R 27/26 (2006.01); H01L 49/02 (2006.01)
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
OG exemplary drawing
 
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.