P
Peter
Guest
What you want is a linear phase low pass filter. Williams and Taylor are a full bottle on the subject.
https://www.amazon.com/Electronic-Filter-Handbook-McGraw-Hill-Handbooks/dp/0071471715
This means that you get a smooth and monotonic transition between voltage steps. It doesn\'t roll off the high frequency content of the step edge all that fast - a higher order linear phase filter will do that better, but you need more precise reactance values to keep close enough to linear phase.
The two amplifier version of the Sallen-Keys 2-pole low pass filter lets you use the same value of capacitance in both the capacitors, and you can use E92 resistors to get very close to the linear-phase characteristic.
Do you mean the one here
https://www.electronics-tutorials.ws/filter/second-order-filters.html
but two of them cascaded?