A method for operating a charge pump having a variable switching frequency may include comparing a target minimum output voltage with an output voltage generated at an output of the charge pump and controlling switching of switches of the charge pump based on the comparison such that the variable switching frequency varies as an output current driven by the charge pump varies.

A method for using driver circuitry to drive a load having an unknown impedance magnitude includes (a) in a configuration mode of the driver circuitry, determining a required power supply voltage for a driver stage to drive the load, and (b) in a driving mode of the driver circuitry, (1) driving the load via the driver stage in response to an input signal, and (2) controlling a power supply to provide the required power supply voltage to the driver stage as a static voltage, while driving the load via the driver stage in response to the input signal.

An electromagnetic energy delivery apparatus comprises: an amplifier; an amplifier input configured to provide to the amplifier a signal to be amplified; bias circuitry configured to provide a bias signal to the amplifier, wherein amplifying of the input signal by the amplifier is dependent on the bias signal provided by the bias circuitry; an amplifier output configured to provide an output signal comprising an amplified version of the input signal, for providing energy delivery to a radiating element to produce electromagnetic radiation; and a controller configured to control operation of the bias circuitry to provide a time- varying bias signal thereby to provide a desired time variation of the output signal.

A variable-gain power amplifying technique includes generating, with a network of one or more reactive components included in an oscillator, a first oscillating signal, and outputting, via one or more taps included in the network of the reactive components, a second oscillating signal. The second oscillating signal has a magnitude that is proportional to and less than the first oscillating signal. The power amplifying technique further includes selecting one of the first and second oscillating signals to use for generating a power-amplified output signal, and amplifying the selected one of the first and second oscillating signals to generate the power-amplified output signal.

A power converter may include an input for receiving an input signal and output for generating an intermediate signal that is a power converted signal from the input signal wherein the intermediate signal is determined based on various parameters of a signal path that utilizes the intermediate signal, wherein the various parameters comprise one or more of the following: a peak output signal of the signal path, energy requested over a period of time by the signal path, available energy from an energy source to the power converter, stored energy at an output of the power converter, and stored energy of a battery for providing electrical energy at the input.

A field-effect transistor system is provided that comprises a field-effect transistor having a back-gate terminal that can be adjusted by a back-gate voltage, a gate-source voltage and a drain-source voltage additionally being present at the field-effect transistor, and a drain current flowing through the field-effect transistor. In addition, the field-effect transistor system includes a control unit connected to the back-gate terminal, which unit is set up to set the drain current flowing through the field-effect transistor to a setpoint current via a controlling of the back-gate voltage at the back-gate terminal, the controlling of the back-gate voltage taking place as a function of at least the gate-source voltage. In addition, a method is provided for setting a drain current of a field-effect transistor.

A variable-gain power amplifying technique includes generating, with a network of one or more reactive components included in an oscillator, a first oscillating signal, and outputting, via one or more taps included in the network of the reactive components, a second oscillating signal. The second oscillating signal has a magnitude that is proportional to and less than the first oscillating signal. The power amplifying technique further includes selecting one of the first and second oscillating signals to use for generating a power-amplified output signal, and amplifying the selected one of the first and second oscillating signals to generate the power-amplified output signal.

An apparatus includes a controller that controls operation of an amplifier. The amplifier receives a sample voltage produced by a resistive path; the sample voltage from the resistive path is indicative of a magnitude of current through a motor winding. The controller selects a gain setting to apply to the amplifier based on one or more conditions. The selected gain setting is selected amongst multiple possible gain settings. Subsequent to selection, via application of the selected gain setting to the amplifier, and based on an output of the amplifier, the controller monitors a magnitude of the current through the motor winding. According to one configuration, the amplifier adjusts the magnitude of the selected gain setting depending on one or more parameters such as the magnitude of the current through the motor winding, a selected operational range of controlling current through the motor winding, etc.

A system may include a power converter having a maximum allowable input power drawn from a power source, an energy storage element coupled to an output of the power converter at a top plate of the energy storage element, wherein the energy storage element is configured to store excess energy, and control circuity configured to, when an input power of the power converter exceeds the maximum allowable input power, cause excess energy stored in the energy storage element to be consumed by circuitry coupled to the output of the power converter, and in order to maintain positive voltage headroom for the circuitry coupled to the output of the power converter, selectively couple a bottom plate of the energy storage element to the power source such that excess energy stored by the circuitry coupled to the output of the power converter is consumed from the energy storage device when the input power of the power converter exceeds the maximum allowable input power.

A system may include a power converter having a maximum allowable input power drawn from a power source, an energy storage element coupled to an output of the power converter at a top plate of the energy storage element, wherein the energy storage element is configured to store excess energy, and control circuity configured to, when an input power of the power converter exceeds the maximum allowable input power, cause excess energy stored in the energy storage element to be consumed by circuitry coupled to the output of the power converter, and in order to maintain positive voltage headroom for the circuitry coupled to the output of the power converter, selectively couple a bottom plate of the energy storage element to the power source such that excess energy stored by the circuitry coupled to the output of the power converter is consumed from the energy storage device when the input power of the power converter exceeds the maximum allowable input power.