A charge compensation circuit is disclosed that provides amplified charge cancellation. A touch controller is disclosed that includes such a charge compensation circuit and may realize improved immunity to baseline capacitance signals that are much larger than a change in capacitance due to proximity of an object. Such a charge compensation circuit may include a capacitor, a driver circuit arranged to apply a pulsed voltage signal to the capacitor, and a current conveyor having a programmable gain and arranged to amplify an initial charge generated by the capacitor in response to the pulsed voltage signal and provide an amplified charge to an output of the charge cancellation circuit.

The present disclosure provides a capacitance detection circuit capable of reducing a chip area. The present disclosure relates to a capacitance detection circuit and an input device. A sense pin of the capacitance detection circuit is connected to a sensor electrode. A first driving unit applies a high voltage or a low voltage to the sense pin. A second driving unit applies the high voltage or the low voltage to a first terminal of a reference capacitor. A third driving unit applies the high voltage or the low voltage to a second terminal of the reference capacitor. A first switch is disposed between the sense pin and the first terminal of the reference capacitor. A second switch is disposed between an input of a post-stage circuit block and the first terminal of the reference capacitor.

A hand-held machine tool (1) including a drive device (4) by which a tool that can be brought into operative connection with the machine tool (1) can be actuated, with a control device (8) for actuating the drive device (4) and at least one capacitive sensor element (30, 35) operatively connected to the control device (8) being provided. The at least one element (2, 75) of the machine tool that is arranged in the region of the capacitive sensor element (30, 35) is grounded.

A capacitive sensor that includes: a sensing electrode having a capacitance to be measured; an alternating voltage source, configured to apply an alternating voltage to the sensing electrode; a capacitive first transfer device; a measurement circuit configured to measure the capacitance of the sensing electrode; and a switching arrangement. The switching arrangement is configured to alternately, in a first switching state, connect the first transfer device to the sensing electrode to enable a charge transfer from the sensing electrode to the first transfer device and, in a second switching state, connect the first transfer device to the measurement circuit to enable a charge transfer from the first transfer device to the measurement circuit.

A capacitance detection circuit, a detection chip, and an electronic device are provided. The circuit includes: a first drive module, a conversion module, a processing module, and a control module. The first drive module is configured to charge a first capacitor to be detected. The conversion module is configured to perform charge conversion processing on the first capacitor to be detected to generate an output voltage. The control module is configured to control a first suppression module of the conversion module to suppress an interference signal with a frequency less than a first frequency or greater than a second frequency when the conversion module generates the output voltage, and the second frequency is greater than the first frequency. The processing module is configured to determine a capacitance change before and after the first capacitor to be detected is affected by an applied electric field based on the output voltage.

A system for sensing touch or proximity include: a first number of input terminals configured to couple one or more capacitive sensors, a second number of transferring units configured to transfer charges from the one or more capacitive sensors through the first number of input terminals in transferring phases of cycles of the one or more capacitive sensor, wherein at least one of the first and second numbers is equal to or greater than two, and a first switching unit, coupled between the first number of input terminals and the second number of transferring units, configured to selectively electrically couple any one of the first number of input terminals to any one of the second number of transferring units in the transferring phases.

An electronic device that includes a first switch, a second switch, a capacitive sensing circuit, and control circuitry. The first switch is electrically coupled between a first terminal of a load and a first terminal for a power source. The second switch is electrically coupled between a second terminal of the load and a second terminal for a power source. The control circuitry is configured to perform operations including connecting the load to the first and second power source terminals by controlling the first and second switches to close during a first portion of a switching cycle, disconnecting the load from the first and second power source terminals by controlling the first and second switches to open during a second portion of the switching cycle, and detecting the capacitance of the load based on the output signal of the capacitive sensing circuit during the second portion of the switching cycle.

A device for detecting steering wheel contact comprises at least a first electrode (12) which is provided in a steering wheel (10) and which forms, together with a human body acting as a second electrode and a dielectric situated therebetween, at least one sensor capacitor (26). The device also comprises an evaluation circuit (24) having a reference capacitor (30) of known capacitance which can be connected parallel to the sensor capacitor (26), a direct current voltage source (34) which can be connected to the reference capacitor (30), and a measuring device for measuring the voltage at the reference capacitor (30). A method for detecting steering wheel contact using such a device comprises the following successive steps: charging the reference capacitor (30) by applying a known reference voltage, or charging the reference capacitor (30) and subsequently measuring a first voltage at the reference capacitor (30); connecting, in parallel, the sensor capacitor (26) to the reference capacitor (30) so that a portion of the charge of the reference capacitor (30) is transmitted to the sensor capacitor (26); measuring a second voltage at the reference capacitor (26); end determining the capacitance of the sensor capacitor (26) from the known capacitance of the reference capacitor (30), the reference voltage or the first voltage and the second voltage.

A method is provided for actuating a hand-held machine tool including a drive device, with a control device for actuating the drive device and at least two capacitive sensor elements operatively connected to the control device being provided. The method includes the following method steps of determining an electrical charge of the first and second sensor element comparing the determined first electrical charge with a defined first threshold value and the determined second electrical charge with a defined second threshold value; enabling the actuation of the drive device and/or defined activation of the drive device via the control device when a predefined condition exists between the determined first electrical charge of the first sensor element and the determined detected second electrical charge of the second sensor element. A machine tool for carrying out a method of this kind is also described.

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.