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 ...

Part 1 of this series addressed a pitfall to be avoided when using Sallen-Key active filters. Please also see my article Avoid Misuse of Sallen-Key Filters. The key point of that essay was that the op ...

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 ...

It is common to see higher-order, multistage, Sallen-Key filters designed with each stage at a gain of 1. This has component-sensitivity advantages, but always produces significant noise gain peaking ...