The overdrive amplifier may include: a differential input circuit arranged by connecting, in a folded-cascode style, input transistors supplied with an input signal at gates, and feedback input transistors accepting the feedback of an output signal at respective gates; a current mirror load having mirror input current paths connected to current paths of the feedback input transistors, and mirror output current paths connected to current paths of the input transistors; an output circuit accepting the input of output control signals from the mirror output current paths of the current mirror load; and an overdrive circuit which causes bias currents of directions which boost an output of the output circuit, depending on the output control signals, to pass through the current mirror load based on the output control signals in an overdrive period.

The disclosure relates to a system and method for controlling a common mode voltage of an output differential signal of a differential signal processing circuit using a replica circuit and feedback control. The differential signal processing circuit includes two load devices, two input transistors, and two current-source transistors coupled in series between voltage rails, respectively. The replica circuit includes replica load device, replica input transistor, and replica current-source transistor coupled in series between the voltage rails. The common mode voltage of the input differential signal is applied to the replica input transistor to generate a replica output common mode voltage. A feedback circuit generates a bias voltage for the replica current-source transistor and the current-source transistors of the differential circuit to set and control the replica output common mode voltage and the output common mode voltage of the differential signal processing circuit to a target common mode voltage.

Exemplary embodiments of the present disclosure are related to baseband filters. A device may include a digital-to-analog converter (DAC) configured to output a DC current. The device may also include an operational amplifier coupled to an output of the DAC and configured to bias an input stage of the operational amplifier with the DC current.

An electronic device includes a transimpedance amplifier stage having an amplifier end stage of the class AB type and a preamplifier stage coupled between an output of a frequency transposition stage and an input of the amplifier end stage. A self-biased common-mode control stage is configured to bias the preamplifier stage. The preamplifier stage is formed by a differential amplifier with an active load that is biased in response to the self-biased common-mode control stage.

An exemplary multipath feedforward amplifier includes a plurality of amplification stages configured to form at least partially distinct amplification paths extending from an input terminal to an output terminal, each amplification path defined by a respective subset of the plurality of amplification stages, wherein at least one amplification stage is a band pass resonator. In various implementations, multipath feedforward amplifier can maximize gain at a frequency of interest by having an amplification path that cascades band pass resonators. In various implementations, the plurality of amplification paths are configured to optimize gain at a center frequency ranging from about 2 GHz to about 3 GHz.

A Radio Frequency (RF) amplifier includes a depletion mode semiconductor device having a gate, a bias device and an inverting circuit. The depletion mode semiconductor device may be a HEMT and/or a MESFET. The bias device is configured to generate a bias voltage. The inverting circuit is configured to generate an inverted bias voltage from the bias voltage, and to apply the inverted bias voltage to the gate. Related circuits and methods are described.

A variable gain amplifier circuit includes a differential pair of transistors and a variable current source circuit. The differential pair of transistors generates an output signal based on an input signal. The variable current source circuit is coupled to the differential pair of transistors. A gain of the output signal relative to the input signal varies in response to variations in a bias current through the variable current source circuit. The variable gain amplifier circuit maintains a common mode voltage of the output signal substantially constant in response to the variations in the bias current through the variable current source circuit.

A Radio Frequency (RF) amplifier includes a depletion mode semiconductor device having a gate, a bias device and an inverting circuit. The depletion mode semiconductor device may be a HEMT and/or a MESFET. The bias device is configured to generate a bias voltage. The inverting circuit is configured to generate an inverted bias voltage from the bias voltage, and to apply the inverted bias voltage to the gate. Related circuits and methods are described.

Disclosed is a circuit having a differential stage comprising a pair or transistors. The transistors are biased by respective bias transistors. Each bias transistor has a respective feedback network configured to reduce transconductance of the bias transistor, to increase a gain of the differential stage.

Amplifiers with bias control for DC coupled single-ended distributed amplifiers of multi-stage amplifiers are described herein. An example amplifier with input bias control includes a distributed amplifier cell having an input coupled to a first distributed transmission line and an output coupled to a second distributed transmission line, an input coupling network coupled between the first distributed transmission line and the input of the distributed amplifier cell, and a bias interface circuit coupled between the input coupling network and the input of the distributed amplifier cell. The amplifier can also include a bias control circuit configured to control an amplifier input bias generated by the bias interface circuit at the input of the distributed amplifier cell.