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.

Various embodiments disclose a method and a device. The device includes: an antenna; a switching regulator; a communication chip including an amplifier, a first linear regulator operably connected to the amplifier and the switching regulator and configured to be supplied with a first voltage from the switching regulator, and a second linear regulator operably connected to the amplifier and the switching regulator and configured to be supplied with a second voltage higher than the first voltage from the switching regulator, the communication chip configured to transmit a radio-frequency signal outside of the electronic device through the antenna; and a control circuit. The control circuit is configured to produce an envelope of an input signal input to the amplifier in connection with the radio-frequency signal and to provide the produced envelope to at least one of the first linear regulator or the second linear regulator. The first linear regulator is configured to provide a third voltage corresponding to the envelope to the amplifier using the first voltage based on the envelope having a voltage in a first range. The second linear regulator is configured to provide a fourth voltage higher than the third voltage to the amplifier using the second voltage based on the voltage of the envelope being in a second range including values larger than values included in the first range.

The present document relates to differential amplifiers. A differential amplifier may comprise a current source, a first transistor, a second transistor, and a compensation circuit. A reference voltage may be applied to a first terminal of the first transistor, and a second terminal of the first transistor may be coupled to an output of the current source. A feedback voltage may be applied to a first terminal of the second transistor, and a second terminal of the second transistor may be coupled to the output of the current source. The compensation circuit may comprise a capacitive element coupled to the first terminal of the first transistor, and the compensation circuit may be configured to reduce a change of the reference voltage at the first terminal of the first transistor.

An amplifier includes a first amplification circuit, a second amplification circuit including first and second amplification transistors controlled by the first amplification circuit to generate first and second output signals and a bias transistor turned on based on a bias signal to generate the first output signal, a filter circuit including a bias capacitor connected to the first amplification transistor and the bias transistor to generate the first bias signal using a first bias voltage, and a feedback circuit configured to receive the first and second output signals and output a feedback signal that adjusts an average of the first and second output signals to correspond to a reference signal, to the first amplifier. The filter circuit adjusts a voltage of the bias capacitor such that a voltage of the bias capacitor when the amplifier is disabled corresponds to a voltage of the bias capacitor when the amplifier is enabled.

The present invention suppresses unevenness of an input/output current of a full bridge circuit, which is caused due to a cross current generated by a delay operation or the like of a switching element and unevenness of a driver voltage of each switching element, and suppresses an occurrence of an erroneous operation of an amplifier of a class-D full bridge circuit. A driver device of a class-D full bridge amplifier according to the present invention sets, at the same potential in terms of DC, reference potentials on a low-voltage side of two high-side driver circuits which drive two high-side switching elements which constitute a full bridge circuit, and suppresses an occurrence of unevenness of a driver voltage of the switching elements due to a cross current which flows between the bridge circuit and the high-side driver circuits. In the configuration in which a plurality of class-D full bridge amplifiers are driven, a driver power supply is individually provided to driver circuits which drive the class-D full bridge amplifiers, and cross currents which flow between the plurality of class-D full bridge amplifiers are suppressed.

An enhanced current mirror can be utilized to accurately control a bias current associated with an amplifier. A current controller component (CCC) can employ the enhanced current mirror and can be associated with the amplifier. The CCC can comprise a comparator that can compare an adjusted supply voltage level to a reference voltage level, the adjusted supply voltage level relating to a supply voltage level of a supply voltage supplied to the amplifier and CCC. The CCC can control switching of an operational state of a transistor of the comparator to switch in or out a resistance of a reference resistor component associated with the supply voltage, based on a result of the comparison of the adjusted supply voltage level to the reference voltage level, to facilitate accurately controlling an amount of bias current associated with the amplifier. The CCC and amplifier can be situated on the same die.

A power amplifier module includes first and second amplifiers, a first bias circuit, and an adjusting circuit. The first amplifier amplifies a first signal. The second amplifier amplifies a second signal based on an output signal from the first amplifier. The first bias circuit supplies a bias current to the first amplifier via a current path on the basis of a bias drive signal. The adjusting circuit includes an adjusting transistor having first, second, and third terminals. A first voltage based on a power supply voltage is supplied to the first terminal. A second voltage based on the bias drive signal is supplied to the second terminal. The third terminal is connected to the current path. The adjusting circuit adjusts the bias current on the basis of the power supply voltage supplied to the first amplifier.

Microwave amplifiers tolerant to electrical overstress are provided. In certain embodiments, a monolithic microwave integrated circuit (MMIC) includes a signal pad that receives a radio frequency (RF) signal, a ground pad, a balun including a primary section that receives the RF signal and a secondary section that outputs a differential RF signal, an amplifier that amplifies the differential RF signal, and a plurality of decoupling elements, some of them electrically connected between the primary section and the ground pad, others electrically connected in the secondary section to a plurality of the amplifier's nodes, and operable to protect the amplifier from electrical overstress. Such electrical overstress events can include electrostatic discharge (ESD) events, such as field-induced charged-device model (FICDM) events, as well as other types of overstress conditions.

A radio frequency circuit includes a power amplifier configured to selectively amplify one of a first radio frequency signal and a second radio frequency signal that have different bandwidths, and when the first radio frequency signal is input to the power amplifier, a first bias signal is applied to the power amplifier, and when the second radio frequency signal is input to the power amplifier, a second bias signal different from the first bias signal is applied to the power amplifier.

Techniques are described for dynamically changing a power draw from a power source of a portable device based on an audio output of the portable device. In an example, the portable device determines that an audio signal to be output by the portable device is associated with an audio mode. The portable device sets a voltage of a power converter of the portable device to a voltage level based at least in part on the audio mode. An amount of power is supplied from a power source of the portable device to the power converter based at least in part on the voltage level. In addition, the portable device outputs the audio signal based at least in part on the amount of power.