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. […]
Understanding
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 […]
Understanding Passive Band Pass Filter with Formulas
The purpose of passive band pass filters is to filter or isolate particular frequencies within a given band. As a result, undesired frequencies outside of the intended range can be attenuated while the right frequencies can flow through selectively. As was previously noted, a non-polarized capacitor and a single series resistor may be used to accurately […]
Understanding Passive High Pass Filter with Formulas
As we already know, a low-pass filter selectively permits signals with frequencies lower than its cutoff frequency fc to pass through. This shows that although the high-frequency elements of the input signal are attenuated (weakened), the lower-frequency elements are retained in the output. A passive high-pass filter, on the other hand, functions in the opposite […]
Understanding Capacitive Reactance with Formulas
Capacitors have a special way of opposing alternating current (AC) which is called capacitive reactance. This is like an internal resistance in the capacitor which changes based on the frequency of the electricity flowing through it. Unlike normal resistance which stays the same, no matter how fast the electricity changes (frequency), capacitive reactance is affected […]