放大器非線性失真研究裝置設計與測試

競之　李希平

摘 要：基于STM32F334單片機設計制作的一個放大器非線性失真研究裝置。該設計采用晶體管放大電路將信號源放大，使用四雙向模擬開關（CD4066BM）做模擬開關，利用單片機自帶ADC采集電壓變化，用FFT算法實現的低頻諧波失真度的測量。使用THD的計算公式計算出線性放大器的“總諧波失真”近似值。通過EKT043顯示觸摸屏顯示當前輸出波形和失真度并且可以通過按鍵進行波形選擇。

關鍵詞：STM32F334單片機 晶體管 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