D类放大器的随机脉宽调制技术研究和分析

在D类放大器中,传统脉宽调制信号含有大量的高次谐波,对传导电磁干扰的产生有很大的影响。提出一种随机脉宽调制技术,能够有效地抑制和降低高次谐波的峰值。应用统计学原理,建立了随机调制信号的功率谱密度理论模型,从理论和仿真的角度,考察不同随机方式对抑制谐波能力的影响。结果表明,随机开关频率和脉冲位置相结合的调制方法具有更好的降低谐波峰值和扩展功率谱的能力,从而有利于改善D类放大器中的电磁干扰问题。

Study and Analysis on Randomized Pulse-width Modulation Scheme for Class D Amplifier

In class B amplifier,pulse-width modulation signal contains large quantity high-or harmonic,and has serious influence on the production of electromagnetic interference(EMI).A randomized pulse-width modulation scheme is proposed,which could effectively control and decrease the high-order harmonic.And by applying the statistic theory,the theoretical model of the power spectral density for the randomized pulse-width modulation is established,and the influence of different randomness schemes on the control of h...