The present disclosure relates to devices and methods for detecting and preventing occurrence of a saturation state in a power amplifier. A power amplifier module can include a power amplifier including a cascode transistor pair. The cascode transistor pair can include a first transistor and a second transistor. The power amplifier module can include a current comparator configured to compare a first base current of the first transistor and a second base current of the second transistor to obtain a comparison value. The power amplifier module can include a saturation controller configured to supply a reference signal to an impedance matching network based on the comparison value. The impedance matching network can be configured to modify a load impedance of a load line in electrical communication with the power amplifier based at least in part on the reference signal.

A detection apparatus for unbalanced DC link capacitor voltage, the DC link provides a DC voltage and includes a plurality of capacitors coupled in series to two ends of the DC link and a plurality of balanced resistors coupled in series to two ends of the DC link and corresponding to the capacitors. The detection apparatus includes a plurality of sense resistors and a current sensor. One end of each sense resistor is coupled to a common-connected node of two capacitors, and the other end thereof is coupled to a common-connected node of two balanced resistors. The current sensor is coupled to one of the sense resistors and measures a current value of a current flowing through the sense resistor coupled to the current sensor.

The invention relates to a circuit containing a transimpedance amplifier for converting two input currents into two output voltages, having a first amplifier part containing a first input, to which a first input voltage is applied, and into which a first input current flows, and having a second amplifier part containing a second input, to which a second input voltage is applied and into which a second input current flows, wherein the first amplifier part and the second amplifier part are connected to a common supply voltage, the first amplifier part and the second amplifier part are connected to a common current source, the input of the first amplifier part and the input of the second amplifier part have a differing direct voltage, and the first amplifier part and the second amplifier part are designed such that an output voltage of the first amplifier part is proportional to the input current of the first amplifier part and an output voltage of the second amplifier part is proportional to an input current of the second amplifier part.

An envelope tracking supply modulator for a power amplifier is disclosed. The envelope tracking supply modulator comprises a multilevel push-pull converter. The multilevel push-pull converter comprises a control logic configured to generate a first and second control signals based on an envelope reference signal; a source multilevel converter configured to receive the first control signal and generate a source multilevel power supply signal; a sink multilevel converter configured to receive the second control signal and generate a sink multilevel power supply signal. The envelope tracking supply modulator further comprises a power recycling supply coupled to the sink multilevel converter; a low-pass filter coupled to outputs of the source and sink multilevel converters to filter the power supply signals generated from the source and sink multilevel converters.

Certain aspects of the present disclosure are generally directed to circuitry and techniques for current sensing. For example, certain aspects provide a circuit for signal amplification including a first amplifier, a second amplifier, and a third amplifier. The circuit also includes a first capacitive element coupled between a first output of the first amplifier and a first input of the third amplifier, a second capacitive element coupled between a second output of the first amplifier and a second input of the third amplifier, a third capacitive element coupled between a first output of the second amplifier and the first input of the third amplifier, and a fourth capacitive element coupled between a second output of the second amplifier and the second input of the third amplifier.

This application relates to current sensing, in particular for a signal processing circuit (500) for outputting an output signal (Sout) based on an input signal (Sin). An output stage (101) includes an output transistor (102) driven, in use, by a drive signal. A current monitor (501) is configured to monitor, in use, a first current through the output transistor, wherein the current monitor comprises a current sensor (105) having a sense transistor (106) configured to be driven based on the drive signal so as to generate a sense current related to the first current. A compensation controller (301) receives an indication of signal level of the input signal and controllably varies operation of the current monitor (501) so as to at least partially compensate for signal-dependent variation in a relationship between the first current and the first sense current.

A power conversion system comprising a system controller configured to generate an input signal in response to a system input and a switch controller coupled to the system controller, the switch controller configured to control a power switch. The switch controller comprises a driver interface configured to receive the input signal that indicates whether the power switch should be ON or OFF, the driver interface further configured to transmit one or more current pulses across a galvanic isolation using an inductive coupling. The driver interface further comprises a first local power supply configured to increase an output voltage of the first local power supply when a transmission of current pulses is imminent.

Examples provide methods and apparatus for controlling a DC bias current in an RF amplifier. In one example where the RF amplifier is implemented on an amplifier die, a reference voltage is produced across a reference resistor implemented on the amplifier die, the DC bias current is measured, and a current controller, which is implemented on a controller die that is separate from the amplifier die, operates a feedback loop using the reference voltage to control a level of the DC bias 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 device includes an amplifier for amplifying and supplying a high frequency power supplied to a load, a parameter detector for detecting a parameter of a current, a voltage, or a power from the amplifier to the load, a current supply unit for supplying a driving current for the amplifier, and an output unit for outputting a command signal for changing an amplification degree of the amplifier based on the detected parameter such that the parameter becomes a target value. The device further includes a first abnormality detector for detecting an abnormality by monitoring the command signal, and/or a current detector for detecting the driving current, a current data storage unit storing an upper and a lower limit value of the driving current, and a second abnormality detector for detecting the abnormality based on at least one of the upper limit value or the lower limit value.