An amplifier circuit with an overshoot suppress scheme is provided. The amplifier circuit includes an input amplifier, an output amplifier and a diode device. The output amplifier is coupled to the input amplifier and outputs an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

A power amplifier using multi-path common-mode feedback loops for radio frequency linearization is disclosed. In one aspect, a complementary metal oxide semiconductor (CMOS) power amplifier containing cascoded n-type field effect transistors (NFETs) and cascoded p-type FETs (PFETs) may have a common-mode feedback network and provides bias voltages that are dynamically varying with the signal power to keep the output common-mode fixed around a half-supply level, while the small-signal and large-signal transconductances of the FET's are kept balanced. A further feedback network may be associated with the supply voltage to assist in providing a symmetrical supply signal. The symmetrical supply signal allows for supply variations without introducing distortion for the power amplifier stage.

In an example, a system includes an amplifier having an output stage configured to provide an output voltage, where the output stage includes a p-channel transistor and an n-channel transistor. The system includes a sense transistor having a gate coupled to a gate of the p-channel transistor, where the sense transistor is configured to sense a current of the p-channel transistor and produce a sense current. The system includes a current mirror coupled to the sense transistor and configured to provide the sense current to a gate of a control transistor, the control transistor having a source coupled to the gate of the p-channel transistor. The system includes a reference current source coupled to the control transistor and configured to provide a reference current. The control transistor is configured to adjust a gate current provided to the p-channel transistor based on comparing the sense current to the reference current.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier includes a PMOSFET and an NMOSFET. The PMOSFET has a gate electrode serving as a first input end and a drain coupled to an output end. The NMOSFET has a gate electrode serving as a second input end and a drain coupled to the output end. The output amplifier outputs an output voltage at the output end, and is coupled to the input amplifier via at least one of the first and second input ends. The diode device is coupled between the output end and the at least one of the first and second input ends of the output amplifier. When a voltage difference between the output end and the at least one of the first and second input ends of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier includes a PMOSFET and an NMOSFET. The PMOSFET has a gate electrode serving as a first input end and a drain coupled to an output end. The NMOSFET has a gate electrode serving as a second input end and a drain coupled to the output end. The output amplifier outputs an output voltage at the output end, and is coupled to the input amplifier via at least one of the first and second input ends. The diode device is coupled between the output end and the at least one of the first and second input ends of the output amplifier. When a voltage difference between the output end and the at least one of the first and second input ends of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier is coupled to the input amplifier and outputs an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier is coupled to the input amplifier and outputs an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier is coupled to the input amplifier and outputting an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced. The diode device includes a variable resistor to increase the barrier voltage of the diode device.

An amplifier circuit is provided. The amplifier circuit includes an amplifier stage; a plurality of variable transistors connected to the amplifier stage; a transconductor connected to at least one of the plurality of variable transistors; and a hybrid differential envelope detector and full-wave rectifier connected to the transconductor.

An amplifier circuit including an input amplifier, an output amplifier and a diode device is provided. The output amplifier is coupled to the input amplifier and outputting an output voltage. The diode device is coupled between an output end and an input end of the output amplifier. When a voltage difference between the output end and the input end of the output amplifier is greater than a barrier voltage of the diode device, the diode device is turned on, and an overshoot of the output voltage is reduced. The diode device includes a variable resistor to increase the barrier voltage of the diode device.