Abstract: In a variable gain amplifier, a base of a bipolar first transistor receives a first differential input signal. The emitter of the first transistor is connected in series between a first resistor and a MOSFET coupled to ground. An output of the amplifier is a current through the collector. The conductivity of the MOSFET controls a gain of the amplifier. A bipolar second transistor receives a second differential input signal, and the second transistor provides a modulated gate voltage to the MOSFET. The drain voltage of the MOSFET is modulated by the first differential input signal and thus undesirably generates distortion. To reduce the distortion, the modulated gate voltage causes the AC component for a certain DC voltage at the drain of the MOSFET to be lowered, improving linearity. Since no current source is used, the amplifier has a large headroom, allowing operation using a low operating voltage.

Abstract: A power management system, which includes a parallel amplifier circuit and a switch mode power supply converter, is disclosed. The switch mode power supply converter cooperatively operates with the parallel amplifier circuit to form the power management system. The power management system operates in one of a high power modulation mode, a medium power modulation mode, and a low power average power tracking mode. Further, during the high power modulation mode and the medium power modulation mode, the power management system controls a power amplifier supply voltage to a radio frequency power amplifier to provide envelope tracking. During the low power average power tracking mode, the power management system controls the power amplifier supply voltage to the radio frequency power amplifier to provide average power tracking.

Abstract: There is disclosed a power supply stage, and a method of controlling such, comprising: a means for generating an intermediate supply signal in dependence on a reference signal representing a desired power supply; and a plurality of adjusting means, each adapted to generate an adjusted supply signal tracking the reference signal, in dependence on the generated intermediate supply signal and the reference signal.

Abstract: Tunable matching circuits for power amplifiers are described. In an exemplary design, an apparatus may include a power amplifier and a tunable matching circuit. The power amplifier may amplify an input RF signal and provide an amplified RF signal. The tunable matching circuit may provide output impedance matching for the power amplifier, may receive the amplified RF signal and provide an output RF signal, and may be tunable based on at least one parameter effecting the operation of the power amplifier. The parameter(s) may include an envelope signal for the amplified RF signal, an average output power level of the output RF signal, a power supply voltage for the power amplifier, IC process variations, etc. The tunable matching circuit may include a series variable capacitor and/or a shunt variable capacitor. Each variable capacitor may be tunable based on a control generated based on the parameter(s).

Abstract: The present disclosure relates to power supply circuitry that has wide bandwidth and achieves high efficiency by using at least one energy storage element for efficient power transfer between two power supply circuits and to an amplitude modulated load. Specifically, the power supply circuitry may include a first power supply circuit, which may be a switching power supply circuit, a second power supply circuit, which may be a linear power supply circuit and may include the energy storage element, and control circuitry to facilitate efficient power transfer. The control circuitry may select one of multiple operating modes, which may include a first operating mode, during which the first power supply circuit may provide power to the energy storage element, and a second operating mode, during which the second power supply circuit may provide power to the amplitude modulated load from the energy storage element.

Abstract: A power module at least includes an ET (Envelope Tracking) module. The ET module includes a buck converter, an inductor, and a capacitor. The buck converter is coupled to a work voltage. The buck converter has a first input terminal for receiving a first control signal, a second input terminal coupled to a supply node, and a buck output terminal The inductor is coupled between the buck output terminal of the buck converter and the supply node. The capacitor is coupled between the supply node and a ground voltage. The ET module is configured to supply a first adaptive supply voltage at the supply node. The first adaptive supply voltage is determined according to the first control signal.

Abstract: Disclosed herein is a differential amplifier circuit that includes: first and second transistors coupled to form a differential circuit; a first current mirror circuit generating first and second currents in response to a third current flowing through the first transistor; and a second current mirror circuit generating a fourth current in response to a fifth input current. A sum of the second and fourth currents flowing through the second transistor.

Abstract: Systems and methods are provided for amplifying multiple input signals to generate multiple output signals. An example system includes a first channel, a second channel, and a third channel. The first channel is configured to receive one or more first input signals, process information associated with the one or more first input signals and a first ramp signal, and generate one or more first output signals. The second channel is configured to receive one or more second input signals, process information associated with the one or more second input signals and a second ramp signal, and generate one or more second output signals. The first ramp signal corresponds to a first phase. The second ramp signal corresponds to a second phase. The first phase and the second phase are different.

Abstract: An amplifier circuit includes an input terminal and an output terminal. A current sinking transistor includes a first conduction terminal coupled to the output terminal and a second conduction terminal coupled to a reference supply node. A voltage sensing circuit has a first input coupled to the input terminal and a second input coupled to the output terminal. An output of the voltage sensing circuit is coupled to the control terminal of the current sinking transistor. The voltage sensing circuit functions to sense a rise in the voltage at the output terminal which exceeds the voltage at the input terminal, and respond thereto by activating the current sinking transistor.

Abstract: Combination circuitry includes a relatively small preamplifier and includes hybrid circuitry. The hybrid circuitry is configured to perform mode switching while also performing some amplification, thus allowing the relatively small preamplifier to be smaller than a conventional power amplifier. In one embodiment, the hybrid circuitry includes first series portion configured to amplify when ON, a first shunt portion, a second series portion configured to amplify when ON, and a second shunt portion. The first series portion may include: a first transistor; a first variable impedance in communication with a gate of the first transistor, wherein the first variable impedance is configured to receive a first transistor control signal; a second transistor in series with the first transistor; and a second variable impedance in communication with a gate of the second transistor, wherein second variable impedance is configured to receive a second transistor control signal.

Abstract: An audio amplifier is powered by a switch mode power supply optimized for audio applications. The power supply includes a rectifier circuit and a discontinuous mode multiphase isolated flyback power circuit and does not require a separate power factor correction stage. The discontinuous mode multiphase isolated flyback power circuit includes multiple isolated flyback converters operating synchronously to each convert a portion of the power and supply a phase-summed direct current voltage to the audio amplifier.

Abstract: Embodiments of RF switching amplifiers are described generally herein. Other embodiments may be described and claimed.

Abstract: Various embodiments are directed to apparatuses and methods to generate a first signal representing modulation data and a second signal representing an amplitude of the modulation data, the first signal and the second signal to depend on an output signal and vary a power supply voltage to a gain stage in proportion to the amplitude of the modulation data.

Abstract: There is provided a radio frequency amplifying apparatus having a protection voltage varying function, including a radio frequency amplifying unit amplifying a radio frequency signal, and a protection circuit unit connected between an output node of the radio frequency amplifying unit and a ground and limiting a voltage in the output node to a level of a preset protection voltage or less when the voltage in the output node is higher than the preset protection voltage, wherein the protection voltage is varied with a control signal.

Abstract: An amplifier circuit, comprising: an input, for receiving an input signal to be amplified; a power amplifier, for amplifying the input signal; a switched power supply, having a switching frequency, for providing at least one supply voltage to the power amplifier; and a dither block, for dithering the switching frequency of the switched power supply. The dither block is controlled based on the input signal. Another aspect of the invention involves using first and second switches, each having different capacitances and resistances, and using the first or second switch depending on the input signal or volume signal. Another aspect of the invention involves controlling a bias signal provided to one or more components in the signal path based on the input signal or volume signal.

Abstract: A power amplifier includes a power amplifier core including a plurality of gain stages to receive a radio frequency (RF) signal and to output an amplified RF signal, an output network coupled to the power amplifier core to receive the amplified RF signal and output a transmit output power signal, and a directional coupler coupled to the output network to obtain a coupled signal proportional to the transmit output power signal. Each of these components can be configured on a single semiconductor die, in an embodiment.

Abstract: Programmable delay circuitry, which includes an input buffer circuit and variable delay circuitry, is disclosed. The variable delay circuitry includes an input stage, a correction start voltage circuit, and a variable delay capacitor. The input buffer circuit is coupled to the input stage, the correction start voltage circuit is coupled to the input stage, and the variable delay capacitor is coupled to the input stage. The programmable delay circuitry is configured to provide a fixed time delay and a variable time delay.

Abstract: A low-noise amplifier (LNA) filter for use with global navigation satellite system (GNSS) devices is disclosed. A first LNA stage, which is configured to connect to an antenna configured to receive GNSS signals, includes an LNA. A second LNA stage, which is connected to the output of the first LNA stage, has a surface acoustic wave (SAW) filter and an LNA. A third LNA stage, which is connected to the output of the second LNA stage, also has a SAW filter and an LNA.

Abstract: Circuits for reducing power consumption in power amplifier circuits are disclosed. In certain embodiments, a circuit for power control in the transmitter includes a coupling circuit, a first power amplifier circuit and a second power amplifier circuit. The coupling circuit includes a primary winding inductively associated with a first secondary winding and a second secondary winding. The coupling circuit provides a signal at output terminals of the first secondary winding and the second secondary winding in response to a signal at the primary winding. A first power amplifier circuit is coupled with output terminals of the first secondary winding, and a second power amplifier is coupled with output terminals of the second secondary winding. The first power amplifier circuit and second power amplifier circuit are configured to be enabled or disabled based on a bias voltage.

Abstract: A multi-band, multi-standard programmable power amplifier having tunable impedance matching input and output networks and programmable device characteristics. The impedance of either or both of the impedance matching input and output networks is tunable responsive to one or more control signals. In one example, the programmable power amplifier incorporates a feedback control loop and the control signal(s) are varied responsive to the feedback loop.