The present invention relates to an amplification device (10) of an input signal comprising: a first amplification stage (12), a second amplification stage (14), each amplification stage (12, 14) comprising: a switching circuit (22), the switching circuit (22) being able to generate, as output (22A, 22B), a switched signal having at least two states, and an inductive element (24) able to smooth the switched signal to obtain a smoothed signal (I1, I3), the smoothed signal (I1, I3) having a useful component and a stray component. The amplification device (10) further comprises a compensation circuit (16), for each amplification stage (12, 14), able to generate a compensation signal (I2, I4) of the stray component of the smoothed signal (I1, I3) generated in the inductive element (24) of the corresponding amplification stage (12, 14).

A MMIC support and cooling structure having a three-dimensional, thermally conductive support structure having a plurality of surfaces and a circuit having a plurality of heat generating electrical components disposed on a first portion of the surfaces and interconnected by microwave transmission lines disposed on a second portion of the plurality of surfaces of the thermally conductive support structure.

An amplification apparatus as the embodiment of the present invention includes a switching amplifier and an adjuster. The switching amplifier is driven on the basis of a control signal and amplifies an input signal to be amplified to generate an amplified signal. The adjuster adjusts the control signal before it is inputted into the switching amplifier. Specifically, the adjuster adjusts at least one of a pulse width of the control signal and a delay time of the control signal with respect to the signal to be amplified.

A gradient amplifier driver stage circuit includes: a gradient coil and a plurality of gradient driver modules electrically cascaded with each other and forming an output end, the output end being electrically connected to the gradient coil, wherein each gradient driver module includes a pre-stage power supply and a bridge amplifier connected in parallel, output voltage of the pre-stage power supplies of the plurality of gradient driver modules are the same, and each gradient driver module is configured to provide an inductive voltage drop and a resistive voltage drop on the gradient coil.

An audio amplifier has a first H bridge and a second H bridge, to drive a speaker as a load. The second H bridge drives the speaker through resistors for increased output impedance. Control logic operates the first H bridge as a class D amplifier for larger amplitudes of audio signal, and operates the second H bridge as a class D amplifier for smaller amplitudes of audio signal. Other aspects are also described and claimed.

An audio amplifier has a first H bridge and a second H bridge, to drive a speaker as a load. The second H bridge drives the speaker through resistors for increased output impedance. Control logic operates the first H bridge as a class D amplifier for larger amplitudes of audio signal, and operates the second H bridge as a class D amplifier for smaller amplitudes of audio signal. Other aspects are also described and claimed.

A power converter produces power at a greater voltage than provided by a power source, while drawing power from the power source, wherein the power converter has a variable input current limit or a variable input power limit. One or more audio amplifiers are configured into i) drawing power from the power source bypassing the power converter and ii) drawing power from the power converter, according to audio signal amplitude, during audio playback and in accordance with an audio signal being amplified. A load of each amplifier is determined for when the amplifier is drawing power from the power source bypassing the power converter. The variable input limit of the power converter is adjusted in accordance with the determined load, during the audio playback. Other aspects are also described and claimed.

An audio amplifier has an analog current source amplifier and a class D amplifier. The analog current source amplifier is active in a first mode to drive a speaker when an audio signal has smaller amplitude. The class D amplifier is active in a second mode to drive the speaker when the audio signal has larger amplitude. Other aspects are also described and claimed.

Systems and methods according to one or more embodiments are provided for correcting a current measurement through a speaker in an audio system. In one example, a system for driving a speaker includes an output stage configured to drive a current through the speaker. The system further includes a first and second current sensor coupled to the output stage and configured to measure a positive current including a first measurement error and a negative current including a second measurement error through the speaker, respectively. The system further includes a processing block coupled to the first and second current sensors to receive the measured positive and negative current signals and configured to add a positive offset value to an input of each first and second current sensors, determine the first and second measurement errors, and correct a measured current using the positive and negative currents and the determined first and second measurement errors.

A MMIC support and cooling structure having a three-dimensional, thermally conductive support structure having a plurality of surfaces and a circuit having a plurality of heat generating electrical components disposed on a first portion of the surfaces and interconnected by microwave transmission lines disposed on a second portion of the plurality of surfaces of the thermally conductive support structure