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US 12,209,889 B2Granted
Device and method for touch sensing
AssigneesSTMicroelectronics France, STMicroelectronics (Grenoble 2) SAS, STMicroelectronics (Rousset) SAS
InventorsLaurent Beyly, Olivier Richard, Kenichi Oku
Life of this patent
Estimating the term…
Abstract
An embodiment of the present disclosure relates to a method of detection of a touch contact by a sensor including a first step of comparison of a voltage with a first voltage threshold; and a second step of comparison of the voltage with a second voltage threshold, the second step being implemented if the first voltage threshold has been reached within a duration shorter than a first duration threshold, the second voltage threshold being higher than the first voltage threshold.
Claims18
A touch sensor comprising:
- a contact capacitor comprising a contact region;
- a first switch having a first conduction terminal coupled to a first electrode of the contact capacitor;
- a reference capacitor having a first electrode coupled to a first power node;
- a second switch having a first conduction terminal coupled to a second electrode of the reference capacitor, and a second conduction terminal coupled to a second conduction terminal of the first switch;
- a third switch having a first conduction terminal coupled to a second power node, and a second conduction terminal coupled to the first conduction terminal of the first switch;
- a fourth switch having a first conduction terminal coupled to the first conduction terminal of the first switch, and a second conduction terminal coupled to the first power node;
- and
- a comparator configured to compare a contact voltage of the contact region with first and second voltage thresholds, the second voltage threshold being higher than the first voltage threshold.
5 more elements
An electronic device comprising:
- a package;
- and
- a touch sensor disposed in the package, the touch sensor comprising:
- a contact capacitor having a contact region on an external surface of the package;
- a first switch having a first conduction terminal coupled to a first electrode of the contact capacitor;
- a reference capacitor having a first electrode coupled to a first power node;
- a second switch having a first conduction terminal coupled to a second electrode of the reference capacitor, and a second conduction terminal coupled to a second conduction terminal of the first switch;
- a third switch having a first conduction terminal coupled to a second power node, and a second conduction terminal coupled to the first conduction terminal of the first switch;
- a fourth switch having a first conduction terminal coupled to the first conduction terminal of the first switch, and a second conduction terminal coupled to the first power node;
- a comparator having a first input coupled to the second conduction terminals of the first and second switches, and a second input coupled to an output of a reference voltage generator;
- and
- a touch sensor signal provided by an output of the comparator.
9 more elements
An electronic device comprising:
- a package;
- and
- a touch sensor disposed in the package, the touch sensor comprising:
- a contact capacitor having a contact region on an external surface of the package;
- a first switch having a first conduction terminal coupled to a first electrode of the contact capacitor;
- a reference capacitor having a first electrode coupled to a first power node, and a second electrode coupled to a second conduction terminal of the first switch;
- a comparator having a first input coupled to the second conduction terminal of the first switch, and a second input coupled to an output of a reference voltage generator;
- a second switch having a first conduction terminal coupled to an output of the comparator;
- a Schmitt trigger having an input coupled to the second conduction terminal of the first switch;
- a third switch having a first conduction terminal coupled to an output of the Schmitt trigger;
- a fourth switch having a first conduction terminal coupled to a second power node, and a second conduction terminal coupled to the first conduction terminal of the first switch;
- a fifth switch having a first conduction terminal coupled to the first conduction terminal of the first switch, and a second conduction terminal coupled to the first power node;
- and
- a touch sensor signal provided by second conduction terminals of the second and third switches.
11 more elements
Dependencies are inferred from the claim text.