Advantages And Disadvantages Of Butterworth Low Pass Filter
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Butterworth low pass filters is a classical method of designing analog filters.
Figure 21 shows a Butterworth low pass filter. The order of the filter was chosen to be a third order filter. The advantages of having a Butterworth low pass filter is the passband is maximally flat. This means the passband of the filter have a smooth and monotonically decreasing frequency response. Another advantage of this type of filter is selecting a higher order filter will then have a steeper attenuation slope near the cut-off frequency each time the order of the filter is increased. However, the disadvantage of increasing the order of the filter is to add more components to the circuit. Another disadvantage of having a Butterworth filter is the roll-off between the passband and stopband have a slow response. There is also ringing and overshoot in the step response.
18.104.22.168.2 Chebyshev filter
The second type of filter that can used is the Chebyshev filter. Figure 22 shows a Chebyshev low pass filter. A third order filter was chosen in this design. The advantage of the Chebyshev filter is the attenuation between the passband and stopband is much steeper than a Butterworth filter, if both filters are of the same filter order. The disadvantages is that there is a ripple at the passband. The step response offers more ringing than the Butterworth filter.
4.3.3 Selection of Design
The Analog laser driver circuit will be used as the chosen design. Since, this circuit is able to