Abstract: A method for capacitive touch sensing with high safety integrity includes measuring at least one of a first mutual-capacitance of an electrode pair comprising two of a first electrode, a second electrode and a third electrode, and a self-capacitance between the third electrode and a body biased to a fixed voltage. A contact of the body to a dielectric overlaying each of the first electrode, the second electrode and the third electrode is detected by comparing at least one of the first mutual-capacitance of the electrode pair to a first reference range, and the self-capacitance to a second reference range.

Abstract: A touch sensitive capacitive keypad system (100) is provided with an analog-to-digital converter, a keypad sensing electrode (114) coupled to measure capacitance voltages using a configurable electrode scan rate, and a controller (120) configured to provide scan-rate independent capacitance voltage measurements from the keypad sensing electrode to the analog-to-digital converter when there is a change in the configurable electrode scan rate by repetitively sampling a capacitance voltage measurements (e.g., 524a-f) from the keypad sensing electrode over a plurality of sequential electrode scan cycles and then discarding a predetermined number of the capacitance voltage measurements (e.g., 524a-b) to generate the scan-rate independent capacitance voltage measurements (e.g., 524c-f) that are provided to the analog-to-digital converter.

Abstract: A touch sensitive capacitive keypad system (100) is provided with an analog-to-digital converter, a keypad sensing electrode (114) coupled to measure capacitance voltages using a configurable electrode scan rate, and a controller (120) configured to provide scan-rate independent capacitance voltage measurements from the keypad sensing electrode to the analog-to-digital converter when there is a change in the configurable electrode scan rate by repetitively sampling a capacitance voltage measurements (e.g., 524a-f) from the keypad sensing electrode over a plurality of sequential electrode scan cycles and then discarding a predetermined number of the capacitance voltage measurements (e.g., 524a-b) to generate the scan-rate independent capacitance voltage measurements (e.g., 524c-f) that are provided to the analog-to-digital converter.

Abstract: A touch sensitive capacitive keypad system (300) is provided with a keypad sensing electrode (304) disposed within sensing proximity of multiple electrodes (E0-E9) and formed under a keypad touch panel having defined key areas, where the electrodes are respectively aligned with the defined key areas to facilitate touch detection at the keypad touch panel with a controller (310) that is configured to determine which of the plurality of defined key areas is being touched by detecting a predetermined signal characteristic at the keypad sensing electrode (304) before sequential scanning the plurality of capacitive key electrodes to identify which capacitive key electrode is aligned with a defined key area being touched.

Abstract: A touch sensitive capacitive keypad system (300) is provided with a keypad sensing electrode (304) disposed within sensing proximity of multiple electrodes (E0-E9) and formed under a keypad touch panel having defined key areas, where the electrodes are respectively aligned with the defined key areas to facilitate touch detection at the keypad touch panel with a controller (310) that is configured to determine which of the plurality of defined key areas is being touched by detecting a predetermined signal characteristic at the keypad sensing electrode (304) before sequential scanning the plurality of capacitive key electrodes to identify which capacitive key electrode is aligned with a defined key area being touched.

Abstract: A capacitive sensor system includes a capacitive sensor device having a sense electrode that includes a first capacitor, a first supply voltage in , a first switch operable to couple the sense electrode to the first supply voltage during a first mode and an analog to digital converter during a second mode, a second switch operable to couple a second capacitor to a second supply voltage during the first mode and to an open circuit during the second mode, and a resistive element that includes a first terminal coupled between the first capacitor and the first switch, and a second terminal coupled between the second capacitor and the second switch.

Abstract: A capacitive sensor system includes a capacitive sensor device having a sense electrode that includes a first capacitor, a first supply voltage in , a first switch operable to couple the sense electrode to the first supply voltage during a first mode and an analog to digital converter during a second mode, a second switch operable to couple a second capacitor to a second supply voltage during the first mode and to an open circuit during the second mode, and a resistive element that includes a first terminal coupled between the first capacitor and the first switch, and a second terminal coupled between the second capacitor and the second switch.