双运放电压模式二阶通用滤波器的实现

视无限增益多路反馈低通滤波器为变形状态变量滤波器,用2个运算放大器、2个电容和4个电阻实现了电压模式二阶通用滤波器.该电路不仅可同时实现低通、带通和高通输出,具有低的无源灵敏度,而且其品质因数、极点角频率与电容比值和电阻比值有关,从而可实现二者的独立、精确调节,实现高精度滤波.此外,该电路中两运算放大器承受的共模电压为零,降低了对运放的要求,电路简单,适合VLSI单片集成技术.通过计算机仿真表明,所提出的电路方案是可行的.

Realization of a novel voltage- mode universal two order filter on two Op- Amp

The infinite gain multiple feedback low-pass filter equals a state variable converted filter.A voltage-mode universal two order filter was designed using two Op-Amps,two capacitors and four resistances.Functions,such as low-pass,band-pass,high-pass filtering,can be realized by changing position of output signal,and its sensitivity is lower.Since its pole angular frequency and quality factor relied on the resistance ratio and capacitor ratio,the parameter of the filter can be tuned accurately and independently,and high-precise filtering was realized.Common-mode signal in input terminal of two Op-Amps of the filter is zero.The circuit is very easy,which makes it suitable for VLSI monolithic integrated circuit technology.Simulation results of EWB prove the veracity of the circuit.