Apparatuses and methods of converting a capacitance measured on a sense element to a digital value are described. One apparatus includes a modulator having a modulator capacitor, a sense element selectively coupled in a feedback loop of the modulator to operate as a switching capacitor. The apparatus also includes a first switch coupled between a voltage source and a first node of the switching capacitor and a second switch coupled between the first node of the switching capacitor and a first node of the modulator capacitor. The switching capacitor provides a charge current to the modulator capacitor via the second switch. The modulator measures a capacitance of the sense element and converts the measured capacitance to a digital code representing the capacitance.

Press-button circuit and a driving method thereof are provided. A press-button circuit includes a first sampling port; a second sampling port; a common terminal; a first control device, coupled to the first sampling port and the second sampling port; at least one first press-button sub-circuit, coupled to the first sampling port and the common terminal; and at least one second press-button sub-circuit, coupled to the second sampling port and the common terminal.

Press-button circuit and a driving method thereof are provided. A press-button circuit includes a first sampling port; a second sampling port; a common terminal; a first control device, coupled to the first sampling port and the second sampling port; at least one first press-button sub-circuit, coupled to the first sampling port and the common terminal; and at least one second press-button sub-circuit, coupled to the second sampling port and the common terminal.

A key scanning method and an input device thereof are provided. The key scanning method for an input device with at least a first key group and a subsidiary key group comprises: triggering a first main scan line electrically connected to the first key group and reading electrical signals received via a plurality of signal sensing lines electrically connected to the first key group to determine whether any said key among the first key group is triggered; and triggering a non-triggered one of a plurality of subsidiary scan lines electrically connected to the subsidiary key group and reading electrical signals received via another plurality of signal sensing lines electrically connected to the subsidiary key group to determine whether any said key among the subsidiary key group is triggered, wherein the first main scan line and the subsidiary scan lines are triggered one after another for multiple times.

A key scanning method and an input device thereof are provided. The key scanning method for an input device with at least a first key group and a subsidiary key group comprises: triggering a first main scan line electrically connected to the first key group and reading electrical signals received via a plurality of signal sensing lines electrically connected to the first key group to determine whether any said key among the first key group is triggered; and triggering a non-triggered one of a plurality of subsidiary scan lines electrically connected to the subsidiary key group and reading electrical signals received via another plurality of signal sensing lines electrically connected to the subsidiary key group to determine whether any said key among the subsidiary key group is triggered, wherein the first main scan line and the subsidiary scan lines are triggered one after another for multiple times.

Apparatuses and methods of converting a capacitance measured on a sense element to a digital value are described. One apparatus includes a modulator having a modulator capacitor, a sense element selectively coupled in a feedback loop of the modulator to operate as a switching capacitor. The apparatus also includes a first switch coupled between a voltage source and a first node of the switching capacitor and a second switch coupled between the first node of the switching capacitor and a first node of the modulator capacitor. The switching capacitor provides a charge current to the modulator capacitor via the second switch. The modulator measures a capacitance of the sense element and converts the measured capacitance to a digital code representing the capacitance.

Apparatuses and methods of converting a capacitance measured on a sense element to a digital value are described. One apparatus includes a modulator having a modulator capacitor, a sense element selectively coupled in a feedback loop of the modulator to operate as a switching capacitor. The apparatus also includes a first switch coupled between a voltage source and a first node of the switching capacitor and a second switch coupled between the first node of the switching capacitor and a first node of the modulator capacitor. The switching capacitor provides a charge current to the modulator capacitor via the second switch. The modulator measures a capacitance of the sense element and converts the measured capacitance to a digital code representing the capacitance.

A circuit, system, and method for converting self capacitance to a digital value may include a pair of charge transfer circuits, each including a switch network, a sensor capacitor or modulation capacitor, and an integration capacitor may be coupled to a comparator to produce a data signal representative of the capacitance of the sensor capacitor of one of the charge transfer circuits. The data signal may be used to indicate a capacitance value of the self capacitance through conversion by a circuit.

A circuit, system, and method for converting self capacitance to a digital value may include a pair of charge transfer circuits, each including a switch network, a sensor capacitor or modulation capacitor, and an integration capacitor may be coupled to a comparator to produce a data signal representative of the capacitance of the sensor capacitor of one of the charge transfer circuits. The data signal may be used to indicate a capacitance value of the self capacitance through conversion by a circuit.

A circuit, system, and method for converting self capacitance to a digital value may include a pair of charge transfer circuits, each including a deadband switch network, a sensor capacitor or modulation capacitor, and an integration capacitor may be coupled to a comparator to produce a bitstream representative of the capacitance of the sensor capacitor of one of the charge transfer circuits. The bitstream may be used to indicate a capacitance value of the self capacitance through conversion by a digitizing circuit element.