Disclosed is a voltage protection circuit for preventing power amplifier burnout in an electronic device. The electronic device includes a power amplifier (PA) configured to amplify a transmission signal, a switch configured to set a path of a signal outputted from the PA, a bias control circuit configured to control the supply of a bias current driving the PA, and a voltage protection circuit configured to provide a main control signal for turning off the PA earlier than turning off the switch based on a battery voltage providing a driving power of the electronic device, and forward the main control signal to the bias control circuit, wherein, in response to receiving the main control signal instructing to turn off the PA from the voltage protection circuit, the bias control unit stops the supply of the bias current driving the PA.

A method comprises: measuring reflected and forward power at a power amplifier output; determining if the reflected power equals to or exceeds a first level; if the reflected power is equal to or exceeds the first level, then reduce power of a power amplifier input signal; determining if a standing wave ratio at the power amplifier output equals or exceeds a second level; if the standing wave ratio at the power amplifier output equals or exceeds the second level, then reducing the power amplifier input signal power level and/or sending an alarm; determining if the power amplifier output power equals or exceeds a third level; and if the power output from the power amplifier equals or exceeds the third level, then reducing the power amplifier input signal power level until such power level is less than or equal to the third level and/or sending an alarm.

An amplification circuit includes a switch circuit, an amplifier, and a control circuit. The switch circuit has a first terminal coupled to a radio frequency signal input terminal or a system voltage terminal, a second terminal coupled to an input terminal of the amplifier, and a control terminal configured to receive a control signal. The amplifier amplifies a radio frequency signal. The control circuit generates the control signal according to a driving current generated by the amplifier. When the control circuit determines that the amplifier operates in a high power mode, the control circuit controls the control signal to adjust a conducting level between the first terminal and the second terminal of the switch circuit according to the intensity of the driving current.

An amplifier overload power limit circuit, system, and a method thereof comprising a monitoring of a current gain of a BJT based on a current detector and limiting power to the BJT based on the monitored current gain to prevent the BJT from driven into a saturation mode and the amplifier overdrive.

A power amplifier includes an amplifying circuit, including an amplifying transistor configured to amplify an input signal and configured to output an output signal, a bias circuit, including a bias transistor comprising an emitter configured to provide a bias current into a base of the amplifying transistor, and a base into which a control current is input, and an overcurrent protecting circuit configured to bypass the control current into a ground, according to a current level of the output signal.

An output OUT is coupled to a load. A high-side transistor MH is arranged such that its source is coupled to a power supply line, and such that its drain is coupled to an output terminal OUT. A first OCP circuit compares a first current detection signal I.sub.CS1 that corresponds to a current I.sub.SRC that flows through the high-side transistor MH with a first threshold value I.sub.OCP having a positive correlation with a power supply voltage V.sub.DD of a power supply line, and generates a first OCP signal S.sub.OCP that indicates the comparison result. A driving circuit latch-stops the driving operation of the high-side transistor MH according to the first OCP signal S.sub.OCP.

Integrated circuits, such as power amplifier integrated circuits, are disclosed containing compact-footprint, vertically-integrated capacitor-avalanche diode (AD) structures. In embodiments, the integrated circuit includes a semiconductor substrate, a metal layer system, and a vertically-integrated capacitor-AD structure. The metal layer system includes, in turn, a body of dielectric material in which a plurality of patterned metal layers are located. The vertically-integrated capacitor-AD structure includes a first AD formed, at least in part, by patterned portions of the first patterned metal layer. A first metal-insulator-metal (MIM) capacitor is also formed in the metal layer system and at least partially overlaps with the first AD, as taken along a vertical axis orthogonal to the principal surface of the semiconductor substrate. In certain instances, at least a majority, if not the entirety of the first AD vertically overlaps with the first MIM capacitor, by surface area, as taken along the vertical axis.

An operational amplifier includes a first output transistor and a second output transistor connected in series between two power nodes, the second output transistor having a semiconductor type opposite to the first output transistor, the first output transistor and the second output transistor being electrically coupled at an output node, and gates of the first output transistor and the second output transistor being connected to a first drive node and a second drive node respectively; and a decoupling capacitor circuit electrically connected between the first drive node and the second drive node.

A power amplifier includes an amplifying circuit, including an amplifying transistor configured to amplify an input signal and configured to output an output signal, a bias circuit, including a bias transistor comprising an emitter configured to provide a bias current into a base of the amplifying transistor, and a base into which a control current is input, and an overcurrent protecting circuit configured to bypass the control current into a ground, according to a current level of the output signal.

Disclosed is an amplifier circuit for providing an output of at least 100 W, preferably of at least 200 W and most preferably of at least 250 W comprising a field effect transistor. A drain of the field effect transistor is connected with a protective feedback circuit. The protective feedback circuit is arranged to reduce an over-voltage energy at the drain of the field effect transistor if the voltage between the gate and a drain of the field effect transistor exceeds a feedback threshold voltage. Further disclosed is a radio frequency amplifier comprising an amplifier circuit, an electrical radio frequency generator comprising the radio frequency amplifier and a plasma processing system comprising an electrical radio frequency generator. Still further disclosed is a method of protecting a field effect transistor in an amplifier circuit.