一种新型文氏桥正弦波发生器的设计_何勇.pdf

35 2 () Vol.35, No.2 2009 4 JO URNA L OF DONGHUA UN IV ERSITY (NATURA L SCIENCE) Apr.2009 　　:1671-0444(2009)02-0194-07 ＊ 何　勇, 陈　磊 ( , 201620) 　:对文氏桥正弦波发生器的反馈网络进行研究, 利用精密整流器和 I 调节器将系统的 出信号反馈到 一个N 沟道耗尽型MOSFET 的栅极, 以实现对文氏桥振荡器的负反馈增益的动态控制.另外分析了文氏桥振荡器的实际振 荡频率受VFA 型运放(Voltage Feedback Amplifier)的有限增益带宽乘积(GB )的影响而产生的误差, 并对电路进行 了仿真.由于 I 调节器对系统引入的滞后校正作用, 增加了系统的稳定性与抗干扰性, 使得新型反馈网络更适用于工 作环境恶劣或对稳定性要求较高的应用场合. :文氏桥振荡器;精密整流器;I 调节器;有限增益带宽乘积(GB ) TN 752　　　 A : : A Novel Design of Wien Bridge Sine Wave Generator H E Y ong , CH E N L ei (College of Mechanical Engineering, Donghua University, Shanghai 201620, China) Abstract:A study on the feedback network of wien bridge oscillator is described.To realize the dynamic control of the negative feedback gain of the wien bridge oscillator, a precision rectifier and a I regulator are used to feedback the output signal into the gate of a N-Channel depletion mode MOSFET .Also, the error produced by the gain-bandwidth product (GB )of the voltage feedback amplifier (VFA )has been analyzed and the circuit has been simulated.By using a I regulator which working as a phase-lag compensation element, the anti-jamming performance is improved and the stability of the system is enhanced, so the sine wave generator is suitable for applications with severe working conditions or stability requirements. Key words:wien bridge oscillator;precision rectifier; I regulator;gain-bandwidth product (GB ) 　　, 、、. , [ 1-4] , ,