放大器非线性失真测试系统设计

Design of amplifier nonlinear distortion test system

以STC8A8K64S4A12单片机为核心设计的放大器非线性失真测试系统,由信号放大电路、有源滤波电路、AD转换电路、显示电路等组成。阐述了测试系统的工作原理,对系统的硬件电路进行了仿真实验,给出了系统测试的软件流程,通过外接不同的信号对系统进行了性能测试,系统可以显示观测图形和输出电压的总谐波失真近似值THD。系统采用分立元器件进行放大电路设计,降低了成本;系统单片机留有多余的接口,便于对系统功能进行扩展;THD测量结果与失真度测试数据进行了比对,误差较小,性能稳定,具有一定应用价值。

The amplifier nonlinear distortion test system based on stc8a8k64s4a12 MCU is composed of signal amplifier circuit,active filter circuit and AD converterCircuit,display circuit,etc.The working principle of the test system is described,the hardware circuit of the system is simulated,and the software flow of the system test is given,The performance of the system is tested by different external signals,and the system can display the observed figure and the approximate THD of the output voltage.The system adopts sub-systemThe cost is reduced by designing the amplifier circuit;The single chip microcomputer of the system has redundant interface,which is convenient to expand the function of the system;Thd measurement results and error analysisCompared with the truth test data,the error is small and the performance is stable,which has a certain application value.