Before we begin our tutorial on active band pass filter circuits, let’s first look at the passband characteristics of several filter types. Low-Pass Filters (LPFs): An LPF’s passband begins at 0 Hz (DC) and extends to the set cut-off frequency (fC). This cut-off frequency corresponds to -3 dB with respect to the maximum passband gain. […]
Active
Active High Pass Filter Circuits Explained with Calculations
Although the fundamental filtering mechanism continues to be the same as in the passive RC filter, the active high-pass filter (HPF) integrates an operational amplifier (op-amp) to provide some essential characteristics. Gain & Control: The op-amp amplifies and controls the gain response of the filter. This is a huge benefit over passive high-pass filters, which […]
Understanding Active Low Pass Filter Circuit with Calculations
As we learned in our previous tutorial, passive filter circuits depend exclusively on passive components such as resistors (R) and capacitors (C) to provide filtering characteristics. A simple example is a first-order low pass filter built with a series resistor and a shunt capacitor across a sinusoidal input. Active filters on the other hand use […]