Abstract: The present invention relates in one aspect to a class D audio amplifier with improved output driver topology supporting multi-level output signals such as 3-level, 4-level or 5-level pulse width or pulse density modulated output signals for application to a loudspeaker load. The present class D audio amplifiers are particularly well-suited for high-volume consumer audio applications and solutions.

Abstract: A multiphase pulse width modulator (PWM) producing N mutually phase shifted PWM signals, which is well-suited for class D audio amplifier applications. The multiphase PWM includes (a) N+1 (N ?2) analog triangular waveform generators producing N+1 mutually phase shifted triangular waveforms, and (b) N+1 comparators each having a first input coupled to each of the N+1 triangular waveforms and a second input coupled to an audio signal to generate N+1 mutually phase shifted PWM phase signals. A crosspoint switch includes N+1 inputs coupled to the N+1 PWM phase signals, and N outputs to supply the N PWM signals. A crosspoint switch controller selectively connects each of the N+1 inputs to each of the N outputs for a duration of a cycle time in a time sequence to simultaneously generate the N PWM signals such that each signal has interleaved time segments of the N+1 PWM phase signals.

Abstract: The present invention relates to a class D audio amplifier comprising a pulse width modulator, an adjustable loop filter and a feedback loop. The pulse width modulator generates a first set of pulse width modulated control signals at an adjustable modulation frequency for respective switch control terminals of a first output driver. A controller of the class D audio amplifier is configured to control frequency response characteristics of the adjustable loop filter based on a frequency setting of the adjustable modulation frequency.

Abstract: The present invention relates in one aspect to a class D audio amplifier with improved output driver topology supporting multi-level output signals such as 3-level, 4-level or 5-level pulse width or pulse density modulated output signals for application to a loudspeaker load. The present class D audio amplifiers are particularly well-suited for high-volume consumer audio applications and solutions.

Abstract: The present invention relates to a class D audio amplifier comprising a pulse width modulator, an adjustable loop filter and a feedback loop. The pulse width modulator generates a first set of pulse width modulated control signals at an adjustable modulation frequency for respective switch control terminals of a first output driver. A controller of the class D audio amplifier is configured to control frequency response characteristics of the adjustable loop filter based on a frequency setting of the adjustable modulation frequency.

Abstract: The present invention relates to a gate driver for a power transistor comprising a first charging path operatively connected between a first voltage supply and a gate terminal of the power transistor for charging the gate terminal to a first gate voltage. A second charging path is connectable between the gate terminal of the power transistor and a second supply voltage to charge the gate terminal from the first gate voltage to a second gate voltage larger or higher than the first gate voltage. A voltage of the second voltage supply is higher than a voltage of the first voltage supply.

Abstract: The present invention relates in one aspect to a class D audio amplifier with improved output driver topology supporting multi-level output signals such as 3-level, 4-level or 5-level pulse width or pulse density modulated output signals for application to a loudspeaker load. The present class D audio amplifiers are particularly well-suited for high-volume consumer audio applications and solutions.