There is provided a differential amplifier including: an inverting input terminal to which a first voltage is applied; a non-inverting input terminal to which a second voltage proportional to the first voltage is applied; and an offset part configured to generate a predetermined input offset voltage between the inverting input terminal and the non-inverting input terminal.

A voltage regulator and a power supply are provided. The voltage regulator includes an operational amplifier and an offset voltage control module. The operational amplifier includes an input terminal and an output terminal, and is configured to generate an output voltage to be output from the output terminal based on a reference voltage received from the input terminal. The offset voltage control module includes one stage of regulation branch or more stages of regulation branches connected in parallel, and is configured to control an offset voltage of the operational amplifier based on selection of the regulation branch to regulate the output voltage. Since sine each stage of regulation branch in the offset voltage control module is based on a transistor structure, as compared with the voltage dividing resistor in the related art, the transistor has lower power consumption, and thus power consumption of the voltage regulator is lowered.

In optical receivers, cancelling the DC component of the incoming current is a key to increasing the receiver's effectiveness, and therefore increase the channel capacity. Ideally, the receiver includes a DC cancellation circuit for removing the DC component; however, in differential receivers an offset may be created between the output voltage components caused by the various amplifiers. Accordingly, an offset cancellation circuit is required to determine the offset and to modify the DC cancellation circuit accordingly.

In optical receivers, cancelling the DC component of the incoming current is a key to increasing the receiver's effectiveness, and therefore increase the channel capacity. Ideally, the receiver includes a DC cancellation circuit for removing the DC component; however, in differential receivers an offset may be created between the output voltage components caused by the various amplifiers. Accordingly, an offset cancellation circuit is required to determine the offset and to modify the DC cancellation circuit accordingly.

A circuit arrangement for generating a supply voltage with a controllable ground potential level includes a voltage source that provides the supply voltage ungrounded, a control unit that generates an adjustable control d.c. voltage to ground, and an operational amplifier that is connected via its voltage supply terminals to the supply voltage source, where the control d.c. voltage is applied to the inverting input of the operational amplifier, the non-inverting input of the operational amplifier is connected via a resistor network to the voltage source and to a ground terminal and the output of the operational amplifier is fed back to the inverting input via a capacitor.

A circuit comprises: a circuit input; a circuit output; at least one passive feedback loop coupled between the circuit output and the circuit input; an active element, coupled in a feed-forward path of the circuit between the circuit input and the circuit output and configured to drive the at least one feedback loop in order to establish a function of the circuit, wherein the feed-forward path of the circuit comprises a second node (Vx) and a first node which are internal nodes of the active element and which are coupled between the circuit input and the circuit output, wherein the first node is configured to have a first voltage, the first voltage being a function of the circuit output, wherein the active element comprises a first voltage drop element coupled between the second node (Vx) and the first node.

An integrated circuit includes a first high-pass filter having an input coupled to receive a first signal and an output coupled to a first input of a first differential pair of transistors. A second high-pass filter includes an input coupled to receive a second signal and an output coupled to a second input of the first differential pair of transistors. The second signal may be a complementary signal of the first signal. A second differential pair of transistors includes control electrodes coupled to a first voltage supply terminal. A boost circuit is coupled between the second differential pair of transistors and the first voltage supply terminal. A low-pass filter is coupled between the first differential pair of transistors and the second differential pair of transistors.

A circuit device includes a differential circuit including differential input terminals; a differential amplifier circuit in which differential input nodes are connected to the differential input terminals; a first power supply terminal supplied with a first voltage; a second power supply terminal supplied with a second voltage; a common terminal; a first resistive element of which one end is connected to one differential input terminal and another end is connected to the common terminal; a second resistive element of which one end is connected to the first supply terminal and another end is connected to the common terminal; a third resistive element of which one end is connected to one differential input terminal and another end is connected to the second supply terminal; a bonding wire, and a capacitor of which one end is connected to the second supply terminal and another end is connected to the common terminal.

A voltage regulator and a power supply are provided. The voltage regulator includes an operational amplifier and an offset voltage control module. The operational amplifier includes an input terminal and an output terminal, and is configured to generate an output voltage to be output from the output terminal based on a reference voltage received from the input terminal. The offset voltage control module includes one stage of regulation branch or more stages of regulation branches connected in parallel, and is configured to control an offset voltage of the operational amplifier based on selection of the regulation branch to regulate the output voltage. Since sine each stage of regulation branch in the offset voltage control module is based on a transistor structure, as compared with the voltage dividing resistor in the related art, the transistor has lower power consumption, and thus power consumption of the voltage regulator is lowered.

The overall performance of a current sense amplifier system may be improved by increasing the common mode rejection of the system. In particular, improved current sense amplifiers may be configured to use a first signal path coupled to the amplifier and a first input terminal, wherein the first signal path is configured to measure the current through a device by generating a voltage proportional to the measured current, wherein the generated voltage includes a small signal voltage with a large common mode voltage, and a second signal path coupled to the amplifier and the first input terminal, wherein the second signal path is configured to reduce the common mode of the generated voltage by level shifting the generated voltage to reduce the common mode voltage.