The two T-notch filter can be used to block unwanted frequencies or if placed in an op amp as a bandpass filter. the notch frequency occurs where the capacitive reactance equals the resistance (Xc = R ...

In the last edition of Don’t Fear the Filter, we built up two examples of the simplest and most-used active filter of all time: the two-pole Sallen-Key lowpass. This time, we’re going to put two of ...

One of the biggest problems for designers of op-amp circuitry arises when the circuit must be operated from a single supply, rather than ± 15 V. This application note provides working circuit examples ...

Michael Steffes challenges conventional approaches to Sallen Key Filter design. He says today's components and VFAs offer greater flexibility. This opinion piece links to more detailed explanations.

As analog engineers, it’s tempting to fantasize about one day coming close to designing the ideal operational amplifier we encountered in college: infinite bandwidth, zero output resistance, and so on ...