频率抖动技术在D类放大器设计中的应用

Application of Frequency Jitter Technique on the Design for the Class D Amplifier

传统的D类放大器采用固定采样频率,引起总谐波失真和电磁干扰等问题。该文先对频率抖动调制技术的工作原理进行分析,然后对D类放大器采用的高频三角波应用频率抖动,通过仿真实验对生成的方波频谱进行分析,验证了采用频率抖动技术可以降低D类放大器的低次谐波的幅度,具有抑制电磁干扰的作用。

The modulation of traditional Class D amplifiers based on the fixed sampling frequency usually caused many problems,such as the total harmonic distortion and electromagnetic interference,etc. This paper analyzed working principle of the jitter frequency modulation in the first,and then promoted a improving method,in which frequency jitter was applied in high-frequency triangle wave used in the Class D amplifiers. By analyzed the frequency spectrum of square-wave,the simulation Experimental result was derived to verify that this method could suppress the amplitude of the lower order harmonic and the EMI.