Pick components, get a filter. Watch the frequency response reshape as you tune R, C, and L for low-pass, high-pass, or resonant band-pass behavior.
Analog Filter DesignerLive
RC & RLC frequency response
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Passive filters shape a signal's frequency content with resistors, capacitors, and inductors. An RC low-pass or high-pass has a cutoff at 1/(2πRC) where the response drops 3 dB; an RLC bandpass resonates at 1/(2π√(LC)) with sharpness set by its quality factor Q.
Reading this result: Low-pass: signals below the 1.6 kHz corner pass, above it they roll off at 20 dB/decade, and the response is exactly 3 dB down right at the corner.
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How it works
Passive filters use resistors, capacitors, and inductors to pass some frequencies and block others. An RC filter sets its −3 dB cutoff at 1/(2πRC); an RLC band-pass resonates at 1/(2π√(LC)) with selectivity given by its quality factor Q. Fundamental to audio, radio, and signal conditioning.
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The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.