论文部分内容阅读
在CCD(电荷耦合器件)输出的原始信号中,混杂有幅度较大的复位脉冲干扰,它是一种高频干扰。为了得到高质量的信号,对原始信号进行低通滤波是一种有效的方法。在许多应用场合,CCD输出的原始信号中有用信号的最大频率为数兆赫。这个频率是由亲奎斯特采样定理决定的。这就要求低通滤波器的截止频率为数兆赫。如果用无源器件制作这个低通滤波器,电感的调整是很麻烦的,而且电路性能不稳定。我们采用电压跟随器LM310制作了截止频率为5MHz的两级巴特沃斯低通滤波器,经示波器观察其性能良好。LM310比一般的高速运算放大器有更好的频率响应,小信号的带宽较宽。在滤波前对输入的信号进行交流耦合并将输入
In the CCD (Charge Coupled Device) output of the original signal, mixed with a larger amplitude of the reset pulse interference, it is a high frequency interference. In order to get a high quality signal, low pass filtering the original signal is an effective method. In many applications, the maximum frequency of useful signals in the original signal output by the CCD is several megahertz. This frequency is determined by the Nyquist sampling theorem. This requires the low-pass filter cut-off frequency of several megahertz. If the passive device is used to make this low-pass filter, the inductance adjustment is very troublesome, and the circuit performance is not stable. We use the voltage follower LM310 produced a two-stage Butterworth low-pass filter with a cut-off frequency of 5MHz, the oscilloscope observed its performance is good. LM310 than the average high-speed op amp has a better frequency response, a small signal bandwidth. The input signal is ac-coupled and input before filtering