放大器非线性失真研究装置设计与测试

竞之　李希平

摘 要：基于STM32F334單片机设计制作的一个放大器非线性失真研究装置。该设计采用晶体管放大电路将信号源放大，使用四双向模拟开关（CD4066BM）做模拟开关，利用单片机自带ADC采集电压变化，用FFT算法实现的低频谐波失真度的测量。使用THD的计算公式计算出线性放大器的“总谐波失真”近似值。通过EKT043显示触摸屏显示当前输出波形和失真度并且可以通过按键进行波形选择。

关键词：STM32F334单片机 晶体管 ADC采集 FFT算法

Design and Test of Amplifier Nonlinear Distortion Research Device

Zang Jingzhi Li Xiping

Abstract：An amplifier nonlinear distortion research device is designed and manufactured based on STM32F334 single-chip microcomputer. The design uses a transistor amplifier circuit to amplify the signal source， uses a four-way analog switch，CD4066BM， as an analog switch， uses the microcontroller's own ADC to collect voltage changes， and uses the FFT algorithm to achieve low-frequency harmonic distortion measurement. The article uses the THD calculation formula to calculate the approximate value of the "total harmonic distortion" of the linear amplifier. The EKT043 display touch screen displays the current output waveform and distortion degree and can select the waveform by pressing the button.

Key words：STM32F334 microcontroller， transistor， ADC acquisition， FFT algorithm