When you design an analog, lowpass, antialiasing filter, you would expect its gain amplitude to continuously decrease beyond the filter's cutoff frequency. For the most part, this assumption is a safe ...

Editor’s note: This article is a follow-up to the 2011 article, ‘Design second- and third-order Sallen Key filters with one op amp’ on EDN. Author’s Note: The author is revising this article to ...

I was concocting a rather silly low-pass filter design, when I remembered that Messrs Sallen and Key did it better in the 1950s, and decided to use their two-pole design to implement a Butterworth ...

Recently, people in various publications have been pointing out that using an ordinary op amp in a Sallen-Key filter can cause problems. A typical op-amp circuit, as shown in Figure 1, can have a ...

There comes a time in every electronic designer’s life when, whether they know it or not, they need an analog filter in their design. If you’re coming from a digital background, where everything is ...

Imperfect Amplifiers, Parasitic Capacitance, And Component Selection All Impact Filter Performance At High Frequencies. Since professors R.P. Sallen and E.L. Key described it in 1955, the Sallen-Key ...