Amplifier devices includes a first amplifier connected to receive an input voltage. The first amplifier outputs an internal voltage. These structures also include a second amplifier having an input node connected to receive the internal voltage and an output node outputting an output voltage. A resistive feedback loop is connected to the input node and the output node of the second amplifier. A first cross-coupled bandwidth boosting stage is connected to the input node of the second amplifier and a second cross-coupled bandwidth boosting stage connected to the output node of the second amplifier. The cross-coupled bandwidth boosting stages form a distributed differential positive feedback structure.

Provided is a reception circuit that suppresses skew of a waveform of a signal and enables high-speed data communication.

A reception circuit according to the present disclosure includes: a first differential stage that receives a first input signal and a second input signal at a first input unit and a second input unit, respectively, and causes first and second currents corresponding to the first and second input signals, respectively, to flow; a second differential stage including a first current path that generates and outputs a first amplified signal corresponding to the first current and a second current path that generates and outputs a second amplified signal corresponding to the second current; a power supply line that supplies power to the first and second differential stages; and at least one variable resistance unit provided in the first or second current path.

The present invention is gallium nitride based operational amplifier because reliability and performance of the gallium nitride is better than the silicon counterpart in radiation environment. The operational amplifier includes four stages, first stage is dual input balanced output differential amplifier, second stage is dual input unbalanced differential amplifier, third stage is buffer stage to couple second and fourth stage, and fourth stage is cascaded common source amplifier with degeneration. A capacitor coupled between second and third stage is to enhance the stability of operational amplifier.

In described examples, an amplifier can be arranged to generate a first stage output signal in response to an input signal. The input signal can be coupled to control a first current coupled from a first current source through a common node to generate the first stage output signal. A replica circuit can be arranged to generate a replica load signal in response to the input signal and in response to current received from the common node. A current switch can be arranged to selectively couple a second current from a second current source to the common node in response to the replica load signal.

A power amplifier circuit includes a first transistor having an emitter electrically connected to a common potential, a base to which a first high-frequency signal is input, and a collector from which a third high-frequency signal is output; a second transistor having an emitter electrically connected to the common potential, a base to which a second high-frequency signal is input, and a collector from which a fourth high-frequency signal is output; a first capacitance circuit electrically connected between the collector of the second transistor and the base of the first transistor; and a second capacitance circuit electrically connected between the collector of the first transistor and the base of the second transistor.

An amplifier circuit comprises a multi-stage amplifier having a plurality of amplifiers cascaded between an input port V.sub.in and an output port V.sub.out to form a differential input stage and N subsequent gain stages, a capacitive load C.sub.L coupled to the output port V.sub.out, and a compensation network coupled to the multi-stage amplifier and configured for positioning Pole-Zero pairs of each stage of the multi-stage amplifier below a unity gain frequency ω.sub.t of the multi-stage amplifier when compensated, with Zeros positioned lower than Poles so as to increase the unity gain frequency ω.sub.t.

A fully-differential two-stage operational amplifier circuit is provided, and it includes a first-stage amplification circuit, a second-stage amplification circuit, a common-mode signal acquisition circuit, a common-mode feedback circuit and a bias circuit. The first-stage amplification circuit has a telescopic structure and receives differential input signals IN.sub.P and IN.sub.N. The second-stage amplification circuit has a common-source structure and outputs differential output signals OUT.sub.P and OUT.sub.N. The common-mode signal acquisition circuit receives differential output signals, and outputs an operational amplifier output common-mode signal V.sub.CMO. The common-mode feedback circuit outputs common-mode feedback signals VB.sub.1 and VB.sub.2 to the first-stage amplifier circuit and the second-stage amplifier circuit respectively; The bias circuit outputs a bias voltage VB.sub.3 to the first-stage amplifier circuit, and outputs bias voltages VB.sub.4 and VB.sub.5 to the first-stage amplifier circuit respectively.

A receiving circuit may include a first amplifying circuit, a second amplifying circuit, a third amplifying circuit, and a feedback circuit. The first amplifying circuit amplifies a first input signal and a second input signal to generate a first amplified signal and a second amplified signal, respectively. The second amplifying circuit amplifies the first amplified signal and the second amplified signal to generate a first preliminary output signal and a second preliminary output signal, respectively. The third amplifying circuit amplifies the first preliminary output signal and the second preliminary output signal to generate a first output signal and a second output signal, respectively. The feedback circuit changes voltage levels of the first amplified signal and the second amplified signal based on a current control signal, the first output signal, and the second output signal.

A circuital system that includes a differential low-pass filter having a differential output and operable in a first voltage domain. Some embodiments include a differential integrator including a differential input and a differential output, and operable in a second voltage domain different from the first voltage domain. Some embodiments include a pair of AC coupling capacitors coupling the differential output of the differential low-pass filter to the differential input of the differential integrator.

A power amplifier circuit includes a first transistor having an emitter electrically connected to a common potential, a base to which a first high-frequency signal is input, and a collector from which a third high-frequency signal is output; a second transistor having an emitter electrically connected to the common potential, a base to which a second high-frequency signal is input, and a collector from which a fourth high-frequency signal is output; a first capacitance circuit electrically connected between the collector of the second transistor and the base of the first transistor; and a second capacitance circuit electrically connected between the collector of the first transistor and the base of the second transistor.