一种无需滤波的D类音频功率放大器

摘要

The traditional class-D audio power amplifier requires external LC filter and increases the cost of increased distortion. According to high efficient and low distortion,a Summing integrator negative feedback scheme and a H-bridge output stage structure circuit is designed,it eliminates the output low pass LC filter. The circuits are completed using Cadence software based on the CSMC 0.6μm BCD process. The simulation results show the THD+N is less than 0.1 %and the efficiency is up to 85 %,when the delivered power is 6 W,the load is 8 Ω and the supply power is 15 V,can meet the prospective specification.%传统的D类音频功率放大器都需要外接LC滤波器，从而增加了成本加大了失真。针对高效率、低失真的要求，设计了一种采用求和积分负反馈技术和H桥输出结构代替滤波器功能的电路结构。电路采用CSMC公司的0.6滋m BCD工艺模型，基于Cadence仿真平台对电路进行了前仿真，仿真结果表明：在15 V电源电压，输出功率为6 W，8Ω负载下芯片效率高达85豫，输出音频信号失真小于0.1豫。