A low pass RC filter is a second-order circuit that allows low-frequency signals to pass through but attenuates frequencies above a cutoff frequency. The user can set the cutoff frequency by adjusting the RC circuit. The Low-pass RC filter blocks high-frequency noise from electric circuits to minimize interference with other devices and prevent distortion in electric circuits.
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What Is a Low Pass RC Filter?
A low-pass RC filter is a special band-pass filter with a restricted transition from passband to stopband. The transmission curve and the impedance plot are similar to a low-pass filter (a.k.a. Butterworth filter) and an ideal low-pass filter with an infinitesimal bandwidth, but the cutoff is different.
Low-pass RC filters have many applications in electronics and telecommunications, such as the first stage RC network in GSM900/DCS1800 mobile phone link path attenuation enhancement and other applications.
Low-Pass RC Filter Working Principle
Are you wondering how does a Low-pass RC filter work? Read this article to understand. A Low-pass RC filter is a kind of 3-term filter. The first stage adds an RC circuit and resistor to the output of the second stage, then the circuit can block high-frequency noise present in the first stage, but low-frequency signals can be transmitted.
The second stage amplifies low frequency and outputs the signal, but when it generated some high-frequency noise and amplified it, we added a 3rd stage to filter out high-frequency noise again.
Where Do We Use a Low-pass RC Filter?
A low-pass RC filter is a reactive (or integrator) circuit or radio frequency (RF) filter that passes low-frequency signals and attenuates, or reduces, signals with frequencies above the cutoff frequency. A low-pass filter works on the same principle as a high-pass filter.
Low-pass or low-cut filters are the ones that can pass low frequencies of the signal but block high frequencies from passing. These filters have been widely used in audio applications because they allow low bass and treble to pass through. Some applications of Low-pass RC filter includes Audio Systems, Measurement Circuits, Filters.
Why Low-Pass RC Filter
A low-pass RC filter is one of the essential passive analog filters. The advantage of this filter is its very low-cost, compact size, and wide range of use. In the following, we can see how to build a simple low-pass RC filter using two resistors and a capacitor.