US 11,929,744 B2
Differential capacitive sensing system
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 Feb. 6, 2020, as Appl. No. 16/783,291.
Claims priority of provisional application 62/950,715, filed on Dec. 19, 2019.
Claims priority of provisional application 62/803,920, filed on Feb. 11, 2019.
Prior Publication US 2020/0259493 A1, Aug. 13, 2020
Int. Cl. G01L 1/14 (2006.01); G01D 5/241 (2006.01); G01R 27/26 (2006.01); H03K 17/975 (2006.01)
CPC H03K 17/975 (2013.01) [G01D 5/241 (2013.01); G01L 1/144 (2013.01); G01R 27/2605 (2013.01)] 25 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
a first set of electrodes;
a second set of electrodes, wherein the first and second sets of electrodes define and form a pathway;
a first electrode disposed in the pathway formed by the first and second sets of electrodes and configured to move along the pathway; and
a capacitance sensing circuit coupled to the first and second sets of electrodes and configured to:
determine a capacitance of a first capacitor based on a first amount of the first electrode between the first set of electrodes;
determine a capacitance of a second capacitor based on a second amount of the first electrode between the first set of electrodes, wherein the first capacitor is coupled in parallel with the second capacitor;
determine a capacitance of a third capacitor based on a third amount of the first electrode between the second set of electrodes; and
determine a capacitance of a fourth capacitor based on a fourth amount of the first electrode between the second set of electrodes, wherein the third capacitor is coupled in parallel with the fourth capacitor, wherein the third capacitor and the fourth capacitor are electrically coupled to the first capacitor and second capacitor.