The present disclosure describes aspects of a capacitance-to-voltage modulation circuit. In some aspects, the circuit is used in touch sensing. In some aspects, a modulation circuit comprises a first pair of switches having one switch connected between a voltage source and a capacitor, and another switch connected between ground and the input of the circuit. The circuit also includes a second pair of switches having one switch connected between the voltage source and the input of the circuit, and another switch connected between ground and the capacitor. A third pair of the circuit's switches comprise one switch connected between the capacitor and an input of an analog-to-digital converter (ADC) and another switch connected between the input of the circuit and the input of the ADC. The third pair of switches may enable charge sharing of signals modulated by the first and second pairs of switches, a result of which can be used to sense touch input based on capacitance at the input of the circuit.

An apparatus and method for determining a valid user input in an electronic device is provided. The electronic device generally includes a touch unit included in a touch input circuit, wherein the touch unit corresponds to a touch area, a signal generator configured to transmit a signal to a first signal line and a second signal line by generating the signal, a signal measuring device configured to measure a part of a modified signal based on the transmitted signal, and a signal determiner configured to determine whether a user input is provided to the touch area based on the measured signal. The first signal line connects the signal generator and the touch unit, and the second signal line extends from the signal generator and is parallel with the first signal line.

Systems and methods receive multiple of trigger signals and responsive to each trigger signal transition a sensing block from operating in a first mode to operating in a second mode by turning on power to one or more portions of the sensing block. Operating in the second mode includes performing multiple sensor scans during multiple sensing periods of a monitoring period. Based on performing a first scan during a first sensing period, systems and methods transition from operating the sensing block in the second mode to operating the sensing block in the first mode by turning off the power to the one or more portions of the sensing block. Based on performing a second scan during a second sensing period, of the plurality of sensing periods, systems and methods transition a processing module from operating in a first processing mode to operating in a second processing mode.

An operation apparatus includes: an operation plate having an operation surface performed by a pressing operation with an operation body; a vibrator including a movable yoke and a fixed yoke for generating a magnetic circuit for guiding a magnetic flux, and an exciting coil for generating the magnetic flux, and the vibrator vibrating the operation plate through a magnetic force generated by an electrical conduction on the exciting coil; a detector detecting a pressing amount by the pressing operation; a press determinator determining based on the pressing amount detected by the detector whether the pressing operation is performed; and a vibration controller for an electrical conduction on the exciting coil when the press determinator determines that the pressing operation is performed. The detector detects the pressing amount by detecting a change in an electrostatic capacitance generated between the movable yoke and the fixed yoke.

A capacitive sensor includes a switching capacitor circuit, a comparator, and a charge dissipation circuit. The switching capacitor circuit reciprocally couples a sensing capacitor in series with a modulation capacitor during a first switching phase and discharges the sensing capacitor during a second switching phase. The comparator is coupled to compare a voltage potential on the modulation capacitor to a reference and to generate a modulation signal in response. The charge dissipation circuit is coupled to the modulation capacitor to selectively discharge the modulation capacitor in response to the modulation signal.

A reading device for capacitive sensing element comprises a differential capacitive sensing element, a modulator, a charge-voltage conversion circuit, a phase adjustment circuit, a demodulator and a low-pass filter. The modulator outputs a modulation signal to the common node of the capacitive sensing element and modulates the output signal of the capacitive sensing element. The two input terminals of the charge-to-voltage conversion circuit are connected to two non-common nodes of the capacitive sensing element. The charge-to-voltage converter read the output charge of the capacitive sensing element and convert it into a voltage signal. The modulator generates a demodulation signal through the phase adjustment circuit. The demodulator receives the demodulation signal from the phase adjustment circuit and demodulates the output of the charge-to-voltage conversion circuit. The low-pass filter is connected to the output of the demodulator for filtering the demodulated voltage signal to output the read signal.

The present invention relates to an evaluation circuit for a capacitive sensor for detecting the distance, speed or position of an object, comprising a reference capacitance and two measuring capacitances, wherein the reference capacitance and the measuring capacitances are supplied with a square-wave voltage via a resistor, and wherein by use of a logic unit a time variable pulse is obtained the duration of which is a measure for the respective measuring capacitance.

A capacitive proximity sensor including a detection circuit, including a detection capacitor, a storage capacitor and switches, a DC voltage generator and a microcontroller which is configured to control the switches and to: obtain a voltage value across the terminals of the storage capacitor and across the terminals of the detection capacitor; calculate a first average defined by the average of the voltage values which are obtained at the end of each iteration of a first acquisition phase and a second average defined by the average of the voltage values at the end of each iteration of a second acquisition phase; and detect a human presence when the difference between the first average and the second average is above a predefined detection threshold.

An impedance measurement circuit for determining a complex impedance of a capacitive sensor that is configured for employing at least one electric heater member as an electrode to be operated in loading mode. The measurement circuit includes: a signal generating unit for providing an electric measurement signal; a signal sensing circuit measuring current through the at least one electric heater member; an electric heater member connection circuit comprising a plurality of MOSFETs for selectively electrically connecting the electric heater member either to the signal sensing circuit for complex impedance measurement or to a DC electric power unit for heating purposes; and a control and evaluation unit that is configured for controlling a switching status of the plurality of MOSFETs according to a predefined sequence, and for determining a complex impedance from the determined currents with reference to a complex reference potential during predefined stages of the predefined sequence.

A wearable sensor is described. In an embodiment, the wearable sensor comprises: an electrically conductive contacting member adapted to be in constant electrical contact with a first part of a user of the wearable sensor: an electrically conductive sensing member adapted to detect an input via an electrical contact caused by a second part of the user; and a dielectric sandwiched between the contacting member and the sensing member to provide a sensor capacitance, wherein, in use, the constant electrical contact and the electrical contact caused by the second part of the user forms a capacitive circuit comprising a capacitance of a portion of the user in parallel to the sensor capacitance. A method of sensing using the wearable sensor and a method for forming the wearable sensor are also described.