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 line driver circuit includes a first input terminal, a second input terminal, a first input stage, a second input stage, a first output stage, and a second output stage. The first input stage includes a first input coupled to the first input terminal, and a second input coupled to the second input terminal. The second input stage includes a first input coupled to the first input terminal, and a second input coupled to the second input terminal. The first output stage includes a first input coupled to a first output terminal of the first input stage and a second input coupled to a first output terminal of the first input stage. A second output stage includes a first input coupled to a second output terminal of the first input stage and a second input coupled to a second output terminal of the first input stage.

An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.

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.

An audio amplifier includes: a buck controller configured to control an output voltage at a first supply terminal, the output voltage selected from a set including a plurality of output voltages, where the output voltage takes a settling time to settle; a first audio bridge including: a class-AB driver stage coupled to the first supply terminal, and a delay insertion circuit configured to receive a processed digital stream and provide the processed digital stream to the class-AB driver stage a delay time after receiving the processed digital stream, where the delay time is based on the settling time; and an audio amplitude detector configured to detect a first peak amplitude in the first digital audio stream, where the buck controller is configured to select a lowest output voltage from the set that is higher than the first peak amplitude plus a headroom voltage.

A ripple pre-amplification based fully integrated LDO pertains to the technical field of power management. The positive input terminal of a transconductance amplifier is connected to a reference voltage Vref, and the negative input terminal of the transconductance amplifier is connected to the feedback voltage V.sub.fb. The output terminal of the transconductance amplifier is connected to the negative input terminal of a transimpedance amplifier and the negative input terminal of an error amplifier. The positive input terminal of the transimpedance amplifier is connected to the ground GND, and the output terminal of the transimpedance amplifier is connected to the positive input terminal of the error amplifier. The gate terminal of the power transistor M.sub.P is connected to the output terminal of the error amplifier, the source terminal of the power transistor M.sub.P is connected to an input voltage V.sub.IN, and the drain terminal of the power transistor M.sub.P is grounded.

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 ripple pre-amplification based fully integrated LDO pertains to the technical field of power management. The positive input terminal of a transconductance amplifier is connected to a reference voltage Vref, and the negative input terminal of the transconductance amplifier is connected to the feedback voltage V.sub.fb. The output terminal of the transconductance amplifier is connected to the negative input terminal of a transimpedance amplifier and the negative input terminal of an error amplifier. The positive input terminal of the transimpedance amplifier is connected to the ground GND, and the output terminal of the transimpedance amplifier is connected to the positive input terminal of the error amplifier. The gate terminal of the power transistor M.sub.P is connected to the output terminal of the error amplifier, the source terminal of the power transistor M.sub.P is connected to an input voltage V.sub.IN, and the drain terminal of the power transistor M.sub.P is grounded.

An apparatus and method are disclosed for providing output signal swings that are greater than the supply voltage in a class-D amplifier. The amplifier circuit boosts the voltage across the amplifier load, such as a loudspeaker, by using capacitors to charge pump the voltage across the load and thus increase the voltage temporarily. This is done by using two or more output bridges rather than one, and connecting the bridges through the capacitors. For signals of less than the supply voltage, only an inner bridge, similar to a full bridge of the prior art, operates. For signals above the supply voltage, an outer bridge charges capacitors, which are then used to boost the voltage on the bridge output for the short period of the Class-D switching period. Thus, only relatively small value boosting capacitors are needed, as they do not need to supply charge for very long.

This application relates to methods and apparatus for multichannel drivers for driving transducers in different channels. A multichannel driver has a plurality of output stages configured such that two output nodes can be modulated between selected switching voltages with a controlled duty cycle to generate a differential output signal across a respective transducer, each output stage being operable with different switching voltages in different modes of operation. A first set of two or more of the output stages are arranged to receive a voltage output by a capacitive voltage generator to use as a switching voltage. A controller is configured to control the mode of operation and duty-cycle of each of the output stages based on a respective input signal and also based on operation of the other output stages of the first set.