Методы моделирования для оценки электромагнитной совместимости звукотехнических систем с импульсными источниками питания и усилителями класса D

Abstract

The known techniques of interference simulation in switching mode operating audio units analyzed. The approach to create a model in the freeware SPICE environment LTSpice offered, with the Line Impedance Stabilization Network and the sound system units` switched-mode operation issues token into account for conducted interference prediction. Conducted interference estimation depending on the load changes at the output of the Burst Mode operating power source carried out. The developed model makes electromagnetic compatibility parameters estimation possible for different values of the audio frequency, load, class D modulation aspects and SMPS modes yet at the design stage. Analysis of simulation results summarized in the paper demonstrates the fundamental possibility of up to 20 dB output noise level reducing at the frequency of 1 MHz by means of the switched-mode power source oscillating frequency changing.