A method, applied in a driving circuit including a bidirectional circuit coupled between a voltage source and a load, includes receiving a feedback signal from the load and an input signal; generating a plurality of pulse width modulation (PWM) signals according to the input signal and the feedback signal; driving the load by the bidirectional circuit according to the plurality of PWM signals such that the input signal and the feedback signal are substantially proportional to each other. The input signal is a time varying signal. The step of generating a PWM signal among the plurality of PWM signals according to the input signal and the feedback signal includes determining a difference according to the input signal and the feedback signal; and generating the PWM signal with a pulse width. The pulse width is determined according to the difference.

A switching amplifier includes a power device and a processing device. The power device is configured for powering a load and is comprised of a plurality of switches. The processing device configured to calculate a switch junction temperature for a bonding wire in each switch based at least in part on a power loss of each switch; generate a first accumulated fatigue damage of the bonding wire in each switch based on the switch junction temperature; and generate an estimated remaining lifetime of the switching amplifier based on the first accumulated fatigue damages of the bonding wires in each switch.

Transistors may be manufactured with a shared drain to reduce die area consumed by circuitry. In one example, two transistors can be manufactured that include two body regions that abut a shared drain region. The two transistors can be independently operated by coupling terminals to a source and a gate for each transistor and the shared drain. Characteristics of the two transistors can be controlled by adjusting feature sizes, such as overlap between the gate and the shared drain for a transistor. In particular, two transistors with different voltage requirements can be manufactured using a shared drain structure, which can be useful in amplifier circuitry and in particular Class-D amplifiers.

A method may include processing a first signal derived from an input signal with a first path to generate a first path voltage at a first path output, processing a second signal derived from the input signal with a second path to generate a second path voltage at a second path output, the second path comprising a linear amplifier having at least one transistor for driving the second path voltage, generating the first signal and the second signal with a signal splitter, such that the second signal comprises information of the input signal absent from the first signal, and such that the second path voltage is of a sufficient magnitude such that the at least one transistor operates in a saturation region of the at least one transistor throughout a dynamic range of a load voltage equal to the difference of the first path voltage and the second path voltage.

A transformer-based antenna switching network includes a transformer having a secondary winding that extends between a first terminal and a second terminal. The first terminal couples to ground through a first switch and connects to a first antenna. The second terminal couples to ground through a second switch and connects to a second antenna.

A digital power amplifier for a signal, the digital power amplifier comprising:

a first activatable amplifier;
a second activatable amplifier; and
an output network,
wherein an output of the first amplifier and an output of the second amplifier are coupled to the output network, and
wherein the amplifiers and/or the output network are configured such that four output levels are obtainable at an output of the output network, and said output levels are configured to optimise a linearity of the digital power amplifier for said signal.

Methods and systems for power amplification with digital quantized power supply with multiple amplifiers are disclosed herein. In one embodiment, In one embodiment, a time-varying envelope signal is sampled, quantized and decomposed into several constituent signals that are individually amplified, and then combined to form a desired amplified version of the quantized time-varying envelope. Amplitude, phase and/or frequency characteristics of one or more of the signals and supply voltages V.sub.dd and source current of one or more amplifiers are digital controlled based on the information provided by quantization process and slow and fast power control information. Amplitude, phase and/or frequency characteristics of one or more of the constituent signals to be amplified are controlled to provide the desired amplitude, phase, frequency, and/or spectral characteristics of the desired quantized version of the time-varying envelope signal.

An embodiment pulse-width modulation (PWM) modulator circuit comprises a first half-bridge stage having a first output node and a second half-bridge stage having a second output node. The first output node and the second output node are configured to have an electrical load coupled therebetween to apply thereto a PWM-modulated output signal. The circuit comprises a differential stage having input nodes configured to receive an input signal applied between the input nodes and produce a differential control signal for the first half-bridge stage and the second half-bridge stage. A current comparator is arranged intermediate the differential stage and the first and second half-bridge stages. The current comparator is configured to produce a PWM-modulated drive signal to drive the half-bridge stages as a function of the input signal applied between the input nodes in the differential stage.

A digital power amplifier comprising at least two individually activatable amplifiers connected to an output network comprising a first hybrid coupler. An output of a first amplifier is connected to a first input of the first hybrid coupler and an output of a second amplifier is connected to a second input of the first hybrid coupler such that activating an amplifier of the at least two amplifiers causes the amplifier to load modulate another activated amplifier of at least two amplifiers.

A nuclear magnetic resonance (NMR) power supply system and method are disclosed. The architecture adopts a two-stage topology to reduce the required capacitance by over ten times, leading to a four-fold improvement in power density. The first stage is an isolated converter that only supplies average power, therefore input filter and transformer sizes can be reduced. The second stage is a fast response DC-DC converter followed by a RF transmitter to produce a pulsed RF signal, so that the mid-point voltage after the first stage can be allowed to droop considerably, leading to much smaller sized capacitors. These and other embodiments enforce the isolated converter to only transfer average power, which reduces the power rating and the volume of the system's transformer.