## Abstract

D-class amplifiers use pulsewidth modulation to transform an input signal u into a rectangular signal p whose duty cycle linearly depends on the input signal u. After low-pass-filtering p to suppress the switching frequency and its harmonics, we obtain the output signal y that is a good approximation of u. This kind of an amplifier is attractive (as compared with the classical A-class and B-class amplifiers) due to its high efficiency. A buck power supply may be regarded as a particular instance of a D-class amplifier. While the operating principle of the D-class amplifier is intuitively clear, a rigorous mathematical analysis of this system is not trivial, as the amplifier is time-varying and nonlinear. We derive a rigorous proof of the fact that the signal p is a good approximation of u in the low-frequency range, and we provide precise error bounds for this approximation.

Original language | English |
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Article number | 5587881 |

Pages (from-to) | 772-776 |

Number of pages | 5 |

Journal | IEEE Transactions on Circuits and Systems II: Express Briefs |

Volume | 57 |

Issue number | 10 |

DOIs | |

State | Published - Oct 2010 |

## Keywords

- D-class amplifier
- Parseval's theorem
- pulsewidth modulation (PWM)
- sampling theorem
- switched power converter
- uniform sampling