A class AB amplifier with improved DC gain. An amplifier includes an input stage and an output stage. The output stage is configured to amplify an output of the input stage. The output stage includes output transistors, class AB amplifier circuitry, minimum selector circuitry, and gain boost amplifier circuitry. The class AB amplifier circuitry includes a first transistor and a second transistor connected as a differential amplifier. The minimum selector circuitry is configured to control bias current in the output transistors by driving a control input of the first transistor. The gain boost amplifier circuitry is coupled to the class AB amplifier circuitry. The gain boost amplifier circuitry is configured to drive a common mode signal onto the control input of the first transistor and a control input of the second transistor, the common mode signal based on the output of the input stage.

An integrated circuit having a plurality of miniaturized transistors, wherein the plurality of transistors include: high concentration transistors which include channel regions having impurity concentrations of a first concentration; and low concentration transistors which include channel regions having impurity concentrations of a second concentration lower than the first concentration.

Methods, circuits, and apparatuses that provide Buffer Amplifier, containing Amplifiers and Buffer Drivers, one or more of the following: ultra low power Buffer Amplifier, capable of having high gain, low noise, high speed, near rail-to-rail input-output voltage span, high sink-source current drive capability for an external load, and able to operate at low power supply voltages. Methods, circuits, and apparatuses that provide regulated cascode (RGC) current mirrors (CM) capable of operating at low power supply and having wide input-output voltage spans.

Methods, circuits, and apparatuses that provide Buffer Amplifier, containing Amplifiers and Buffer Drivers, one or more of the following: ultra low power Buffer Amplifier, capable of having high gain, low noise, high speed, near rail-to-rail input-output voltage span, high sink-source current drive capability for an external load, and able to operate at low power supply voltages. Methods, circuits, and apparatuses that provide regulated cascode (RGC) current mirrors (CM) capable of operating at low power supply and having wide input-output voltage spans.

Disclosed herein are circuits, devices and methods that address challenges associated with power amplifier systems. A power amplifier system includes two or more fast error amplifiers coupled to corresponding power amplifiers. The fast error amplifiers are configured to generate envelope tracking signals based on a signal envelope, the envelope tracking signals modifying a DC-DC regulated voltage from a DC-DC converter to more efficiently operate the power amplifiers. By splitting the envelope tracking between two or more fast error amplifiers and amplification between corresponding two or more power amplifiers, the power, frequency or bandwidth, linearity, signal-to-noise ratio, efficiency, or the like of the power amplifier system can be improved. Wireless communications configurations with such power amplifier systems can provide uplink carrier aggregation and/or cellular signals based on standards and protocols that require increased bandwidth and/or power.

The present disclosure relates to an integrated circuit comprising a transconductance amplifier which is connectable to a microelectromechanical systems (MEMS) transducer. The transconductance amplifier comprises a first input coupled to a first current conveyor and a second input coupled to a second current conveyor for converting a single-ended or differential transducer signal voltage into an intermediate signal current representative of the transducer signal voltage through a shared reference resistor. The transconductance amplifier further comprises first and second output circuits coupled to the shared reference resistor and being configured to convert the intermediate current signal into a corresponding differential output current signal through first and second output terminals for driving a load.

The present invention relates to a novel and inventive compound device structure for a low noise current amplifier or trans-impedance amplifier. The trans-impedance amplifier includes an amplifier portion, which converts current input into voltage using a complimentary pair of novel n-type and p-type current-injection field-effect transistors (NiFET and PiFET), and a bias generation portion using another complimentary pair of NiFET and PiFET. Trans-impedance of NiFET and PiFET and its gain may be configured and programmed by a ratio of width (W) over length (L) of source channel over the width (W) over length (L) of drain channel (W/L of source channel/W/L of drain channel).

A power amplifier includes an input terminal configured to receive a low voltage input signal, an output terminal configured to output a high voltage output signal, and a plurality of amplifiers stacked in series between a first voltage terminal and a second voltage terminal. Each of the amplifiers includes an input capacitor, an output capacitor, an input coupled to the input terminal through the input capacitor, an output coupled to the output terminal through the output capacitor, and a feedback element coupled between the input and the output of the amplifier.

An amplifier includes an input stage, a folded cascode stage, and a class AB output stage. The folded cascode stage is coupled to the input stage. The class AB output stage is coupled to the folded cascode stage. The class AB output stage includes a high-side output transistor, a low-side output transistor, and a high-side feedback circuit that is coupled to the high-side output transistor. The high-side feedback circuit includes a high-side sense transistor and a high-side feedback transistor. The high-side sense transistor includes a control terminal that is coupled to a control terminal of the high-side output transistor. The high-side feedback transistor is coupled to an output of the high-side sense transistor and to the folded cascode stage. A first output of the folded cascode stage is coupled to the control terminal of the high-side sense transistor and to the control terminal of the high-side output transistor.

An apparatus includes a Transimpedance Amplifier (TIA), an input interface and input masking circuitry. The TIA is configured to convert input current pulses into output voltage pulses. The input interface is configured to receive a control signal indicative of one or more time intervals. The input masking circuitry is configured to prevent the input current pulses from saturating the TIA during the one or more time intervals indicated by the control signal.