Butterworth filter is a type of filter whose frequency response is flat over the passband region. Low-pass filter (LPF) provides a constant output from DC up to a cutoff frequency f(H) and rejects all ...

Several people asked for more information about anti-alias filters used with analog-to-digital converters to remove unwanted signals. This column describes a filter-selection "gotcha," and includes ...

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 ...

Analog variable frequency filters require the use of variable passive components. The higher the slope of the filter, the greater the number of needed variable passive components. These elements are ...