在Multisim 10軟件環(huán)境下，設(shè)計一種由運算放大器構(gòu)成的精確可控矩形波信號發(fā)生器，結(jié)合系統(tǒng)電路原理圖重點闡述了各參數(shù)指標的實現(xiàn)與測試方法。通過改變RC電路的電容充、放電路徑和時間常數(shù)實現(xiàn)了占空比和頻率的調(diào)節(jié)，通過多路開關(guān)投入不同數(shù)值的電容實現(xiàn)了頻段的調(diào)節(jié)，通過電壓取樣和同相放大電路實現(xiàn)了輸出電壓幅值的調(diào)節(jié)并提高了電路的帶負載能力，可作為頻率和幅值可調(diào)的方波信號發(fā)生器。Multisim 10仿真分析及應用電路測試結(jié)果表明，電路性能指標達到了設(shè)計要求。
Abstract:
Based on Multisim 10， this paper designed a kind of rectangular-wave signal generator which could be controlled exactly composed of operational amplifier， the key point was how to implement and test the parameter indicators based on the circuit diagram. The duty and the frequency were adjusted by changing the time constant and the way of charging and discharging of the capacitor， the width of frequency was adjusted by using different capacitors provided with multiple switch， the amplitude of output voltage was adjusted by sampling voltage and using in-phase amplifier circuit，the ability of driving loads was raised， the circuit can be used as squarewave signal generator whose frequency and amplitude can be adjusted. The final simulation results of Multisim 10 and the tests of applicable circuit show that the performance indicators of the circuit meets the design requirements.
