使用雙相位雙電壓脈波寬度調變之設計應用於Class D放大器

Abstract

本論文主要是設計一個使用雙電壓雙相位脈波寬度調變之方法,應用於Class D放大器之電路，內部包含一個雙電壓位階及雙相位之三角載波產生器、多個比較器組成的DPDL PWM(Dual Phase and Dual Level Pulse Width Modulation)混合路、雜訊抑制積分電路以及多電壓輸出級之驅動電路。

傳統的類比Class D使用PWM取樣技術，因其驅動輸出級，為了省電之目的，使用數位方波之輸出，所以會有EMI(Electromagnetic Interference)以及THD(Total Homonic Distortion)之失真問題，這是Class D電路所比不上Class A放大器的特性。

本論文改善傳統PWM之單一數位方波輸出的缺點，利用DPDL-PWM之取樣和編碼，利用多電源的輸出去驅動負載，藉此降低EMI及THD之缺點，並保持Class D高驅動效率之優點，來達到兼具低耗能和高性能之目的。可應用在手持產品以實現高效率、高效能的D類放大器。

This thesis proposes the Dual Phase Dual Level PWM for Class D Amplifier that consists of a triangle wave generator circuit with Dual-level and Dual-phase sampling carrier to modulate with input signal，consists of a noise shaping filter to de-noise and consists of a multi power switching circuit to reduce the EMI and distortion. The MLMP-PWM based Class D through the use of technology without any static current consumption can have the advantage of high power efficiency. Although the square output waveform will have the problem of EMI and THD, the proposed Class D can use Dual-level Dual-phase triangle carrier to sample input signal to lower EMI and distortion and switch multi-level output voltage to drive output load for DPDL-PWM waveform similar to continuous sine wave. The proposed Class D achieves high efficiency, low EMI, and low THD by using the DPDL-PWM technology for portable products.