A voltage detection circuit includes a resistance dividing circuit containing a coarse adjustment variable resistance circuit and a fine adjustment variable resistance circuit, a coarse adjustment circuit controlling the coarse adjustment variable resistance circuit, a fine adjustment circuit controlling the fine adjustment variable resistance circuit, and a control circuit controlling the coarse adjustment circuit and the fine adjustment circuit based upon a detection signal of a comparator circuit.

A resistance measuring device includes an amplifying unit including an amplifier, a first and a second current supply unit, a voltage detection unit, and a controller. The controller controls the voltage detection unit to detect a first output voltage of an output terminal of the amplifier in a state where the current of the first current source flows in a forward direction to a measurement target resistor by controlling the first current supply unit, controls the voltage detection unit to detect a second output voltage of the output terminal of the amplifier in a state where the current of the second current source flows in a reverse direction to the measurement target resistor by controlling the second current supply unit, and calculates a resistance value of the measurement target resistor based on the detected first output voltage and the detected second output voltage.

A voltage sensing circuit includes voltage regulators, oscillator circuits, delay circuits, and a detector circuit. The detector circuit detects characteristics of signaling received from a first oscillator circuit and characteristics of signaling received from a second oscillator circuit. The detector circuit compares the detected characteristics of the signaling from the first oscillator circuit and the second oscillator circuit to determine whether the detected characteristics from the first oscillator circuit and the second oscillator circuit meet a particular criterion for providing voltage manipulation for the voltage sensing circuit.

A power detector includes a detection circuit and a bias circuit. The detection circuit is used to receive an input signal and output a power indication signal. The bias circuit includes a first impedance unit, a second impedance unit and a transistor. The transistor includes a first terminal and a control terminal coupled to the first impedance unit, and a second terminal. The second impedance unit is coupled between the first terminal of the transistor and an output terminal of the bias circuit, or between the second terminal of the transistor and a second terminal of the bias circuit. The output terminal of the bias circuit is coupled to an input terminal of the detection circuit, and is used to output a bias signal.

A shunt resistor is connected in series to a load. A differential amplifier circuit are inputted a first voltage that is generated at one end of the shunt resistor and a second voltage that is generated at the other end of the shunt resistor. The differential amplifier circuit outputs a third voltage equivalent to a sum of a reference voltage and a voltage obtained by performing differential amplification on the first voltage and the second voltage. A conversion circuit outputs the voltage obtained by performing differential amplification on the first voltage and the second voltage by removing the reference voltage from the third voltage. The voltage is proportional to a load current.

A power detector includes a detection circuit and a bias circuit. The detection circuit is used to receive an input signal and output a power indication signal. The bias circuit includes a first impedance unit, a second impedance unit and a transistor. The transistor includes a first terminal and a control terminal coupled to the first impedance unit, and a second terminal. The second impedance unit is coupled between the first terminal of the transistor and an output terminal of the bias circuit, or between the second terminal of the transistor and a second terminal of the bias circuit. The output terminal of the bias circuit is coupled to an input terminal of the detection circuit, and is used to output a bias signal.

A readout circuit for resistive and capacitive sensors includes a first input coupled to a reference resistor in a first mode of operation and coupled to a resistive sensor in a second mode of operation; a second input coupled to a capacitive sensor in the first mode of operation and coupled to a reference capacitor in the second mode of operation; and an output for providing a capacitive sensor data stream in the first mode of operation and for providing a resistive sensor data stream in the second mode of operation.

A readout circuit for resistive and capacitive sensors includes a first input coupled to a reference resistor in a first mode of operation and coupled to a resistive sensor in a second mode of operation; a second input coupled to a capacitive sensor in the first mode of operation and coupled to a reference capacitor in the second mode of operation; and an output for providing a capacitive sensor data stream in the first mode of operation and for providing a resistive sensor data stream in the second mode of operation.

A shunt resistor is connected in series to a load. A differential amplifier circuit are inputted a first voltage that is generated at one end of the shunt resistor and a second voltage that is generated at the other end of the shunt resistor. The differential amplifier circuit outputs a third voltage equivalent to a sum of a reference voltage and a voltage obtained by performing differential amplification on the first voltage and the second voltage. A conversion circuit outputs the voltage obtained by performing differential amplification on the first voltage and the second voltage by removing the reference voltage from the third voltage. The voltage is proportional to a load current.

A current sensor is provided with one or more magnetic field sensing elements configured to generate a magnetic field signal indicative of a magnitude of a sensed magnetic field, wherein the sensed magnetic field is related to a magnitude and frequency of a current through a conductor. A signal path is responsive to the magnetic field signal and includes a compensator configured to apply a compensation factor to the magnetic field signal to generate a sensor output signal indicative of the magnitude of the current and substantially independent of a frequency of the current. The sensed magnetic field is related to the magnitude of the current by a coupling factor and the signal path is responsive to a characterization of the coupling factor over a range of frequencies of the current in order to determine the compensation factor to be applied.