A current sensor (12) serves to detect an alternating current (16). The current sensor (12) comprises a coupler (20) designed to decouple a proportional part of the alternating current (16) as a measurement current (22). In addition, the current sensor (12) comprises a switching terminal designed to feed in a switching signal (15). The current sensor (12) furthermore includes a switchable rectifier (21) designed to rectify the measurement current (22) in a manner controlled by the switching signal (15) and to output it as a rectified measurement current (Vsense).

A device having an impedance measurement circuit that allows for reduction of flicker noise can be implemented in a variety of applications. A carrier suppression technique can be implemented that substantially removes the carrier signal with removal of noise artifacts associated with the carrier signal from sidebands of the carrier signal. Carrier suppression in an AC impedance measurement circuit can be implemented by sensing a carrier signal of the measurement circuit at a transmit location of the measurement circuit and subtracting a weighted version of the carrier signal at a receive location of the measurement circuit. One or more compensation impedances can be used such that the sidebands of the carrier signal are received with the carrier signal suppressed with respect to the receive location.

A noise removing circuit may include: a reference voltage control circuit configured to perform a noise detection sequence operation based on noise detection sequence information, and control a reference voltage based on a counting value; a noise detection circuit configured to compare a supply voltage and the reference voltage, and generate a counting value corresponding to noise which has occurred in the supply voltage; a noise calculation circuit configured to generate a loading control signal corresponding to the noise by performing an operation on the counting value and the reference voltage; and a loading control circuit configured to control a loading value for the supply voltage based on the loading control signal.

A current sensor integrated circuit to sense a current through a resistor includes a substrate, a tub disposed in the substrate, an analog front end disposed in the tub and comprising an amplifier having inputs coupled across the resistor and a charging circuit configured to bias the analog front end and the tub to a bias voltage that is a predetermined offset voltage greater than a common mode voltage associated with the resistor. In embodiments, the analog front end is biased to a first bias voltage and the tub is biased to a second, different bias voltage.

The present application relates to current sensing circuitry (100) that comprises a differential amplifier (110) comprising first and second inputs configured to sense a current across a sense resistance, and an output configured to output a current sense signal. The circuitry (100) further comprises a first current source, a second current source and a switch network operable in: a first phase in which the first current source is connected to the first input and disconnected from the output, and the second current source is connected to the output and disconnected from the first input; and a second phase in which the first current source is connected to the output and disconnected from the first input, and the second current source is connected to the first input and disconnected from the output.

Apparatus and associated methods relate to generating a programmable differential threshold with a common mode signal derived from a received signal, and comparing a differential component of the received signal to the programmable differential threshold signal to improve signal loss detection accuracy in the presence of noise. In an illustrative example, the comparison may be performed in a signal loss detection circuit. The signal loss detection circuit may, for example, process a received input signal in an independent path in parallel with a main signal path. The programmable differential threshold may be set to a predetermined level as a function of an acceptable noise level. Based on the comparison, some implementations may advantageously respond to received signal loss, which may result from, for example, a signal path interruption.

The present application relates to current sensing circuitry (100) that comprises a differential amplifier (110) comprising first and second inputs configured to sense a current across a sense resistance, and an output configured to output a current sense signal. The circuitry (100) further comprises a first current source, a second current source and a switch network operable in: a first phase in which the first current source is connected to the first input and disconnected from the output, and the second current source is connected to the output and disconnected from the first input; and a second phase in which the first current source is connected to the output and disconnected from the first input, and the second current source is connected to the first input and disconnected from the output.

An inspection device includes a reference signal output section, a noise removal section, and an electrical characteristic measurement section. The reference signal output section is connected to an external power supply device in electrical parallel with a semiconductor sample, and outputs a reference signal according to the output of the external power supply device. The noise removal section outputs a noise removal signal obtained by removing a noise component of the output of the external power supply device from the current signal output from the semiconductor sample based on the reference signal. The electrical characteristic measurement section measures the electrical characteristic of the semiconductor sample based on the noise removal signal. The inspection device measures the electrical characteristic of the semiconductor sample to which a voltage is being applied by the external power supply device and which is being irradiated and scanned with light. The inspection device outputs a defective portion of the semiconductor sample based on the electrical characteristic.

Integrated circuitry, such as a microcontroller, for controlling an electric motor includes circuitry for measuring a bi-directional current flowing within a coil of the electric motor. The current is sensed by an externally implemented current sensing element, such as a shunt resistor, to produce a differential voltage that is delivered to input pins of the microcontroller, which are protected by electrostatic discharge protection circuits. Current sources implemented within the microcontroller are coupled to the input pins, and work in concert with external resistors to shift the differential voltage so that it is maintained within an appropriate voltage operating range so that an accurate measurement of the bi-directional current can be made by the microcontroller.

A measuring circuit for registering and processing signals received from a transducer having a plurality of transducer elements includes a first signal input, a second signal input and a third signal input. The first signal input is configured to receive a first signal from a first transducer element. The second signal input is configured to receive a first signal from a second transducer element. The third signal input is configured to receive a second signal sum indicative of a sum of a second signal from each of the plurality of transducer elements, each of the second signals being an inverse of a corresponding first signal. A processor is electrically coupled to the three signal inputs and is configured to register each of the first signals individually; register the second sum signal; and generate a differential signal based on the first and second signals.