In one embodiment, an electrical circuit can include one or both of two different circuit architectures that provide robust protection against spurious common-mode signals, including common-mode degradation and transient common-mode signals. When used in electrical isolators, these circuit architectures improve common-mode signal quality over the isolation barrier and maintain signal quality by reducing common-mode degradation.

An example apparatus includes: current source circuitry having a first terminal, a second terminal, a third terminal, and a fourth terminal; current sink circuitry having a first terminal, a second terminal, a third terminal, and a fourth terminal; common mode voltage circuitry having a first terminal and a second terminal, the first terminal of the common mode voltage circuitry coupled to the first terminal of the current source circuitry and the first terminal of the current sink circuitry, the second terminal of the common mode voltage circuitry coupled to the second terminal of the current source circuitry and the second terminal of the current sink circuitry; idle current source circuitry having a terminal coupled to the third terminal of the current source circuitry; and feedback current source circuitry having a terminal coupled to the fourth terminal of the current source circuitry.

A differential amplifier circuit is provided. The circuit includes a PWM modulator for generating a PWM signal representative of a difference between the first and the second staircase-like reference signals and the digital input signal, a DM-IDAC for receiving the PWM signal and providing a first and second differential mode current, a CM-IDAC for receiving the PWM signal and providing a common mode current, first and second loop integrators, and first and second comparators; each loop integrator comprising virtual ground node terminal for receiving the differential mode current, the common mode current, and a feedback signal from an output stage of the differential amplifier circuit via a feedback loop, and integrator output terminal for providing loop integrator output signal proportional to an integral of the signals received at the virtual ground node terminal, the comparators receiving the loop integrator output signal, and triangular reference signal.

The present disclosure relates to a current sensor, including a magnetic-field sensor for measuring a magnetic field induced by an electrical current; an output connection for providing an amplified measurement signal from the magnetic-field sensor, the magnetic-field sensor and the output connection being connected by an analog signal path having at least one amplifier, the analog signal path having a frequency response; a temperature sensor for measuring a temperature; and a compensation circuit which is coupled to the analog signal path and is configured to correct the frequency response of the analog signal path based on the temperature.

Disclosed is a four-phase generation circuit, comprising a pair of input ports configured to receive a differential signal having a common mode voltage; a polyphase filter having a pair of polyphase filter input ports and first, second, third and fourth output ports; a first circuit configured to provide the differential signal with an adjusted common mode voltage to the pair of polyphase filter input ports; wherein the first, second third and fourth output ports are each configured to output a square-wave signal, with 90 phase separation between consecutive output signals; and a feedback circuit from the first, second, third and fourth outputs ports to the first circuit; wherein the feedback circuit is configured to provide a feedback signal to the first circuit to set the adjusted common mode voltage from the common mode voltage.