E.08RC / RL / LC Filter Calculator
Choose the circuit type and enter component values.
Results
- Cut-off / resonant frequency
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- Angular frequency ω
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- Time constant τ
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- Characteristic impedance
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- Period
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Formulas
- RC
- fc = 1 / (2π·R·C) τ = R·C
- RL
- fc = R / (2π·L) τ = L / R
- LC
- f₀ = 1 / (2π·√(L·C)) Z₀ = √(L / C)
Note
At the cut-off frequency a first-order filter’s gain is −3 dB (about 70.7% of the amplitude). Low-pass and high-pass versions share the same cut-off frequency; they differ only in how the components are connected.
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