LC Filter Designer (Butterworth / Chebyshev)
Generates LC ladder component values for classic filter approximations. Butterworth gives maximally flat passband; Chebyshev trades passband ripple for sharper rolloff. Low-pass or high-pass, up to 9th order.
Equations & Parameters ▸
\(\text{LP proto: }g_k\text{ from Butterworth/Chebyshev tables; scaled: }L_k=g_k\frac{Z_0}{\omega_c},\; C_k=\frac{g_k}{Z_0\omega_c}\)
| n | Filter order. Higher order = sharper rolloff but more components. |
| Type | Low-pass (LPF) or High-pass (HPF). Bandpass can be obtained by frequency transformation. |
| Response | Butterworth: flat passband, −3 dB at fc. Chebyshev: equal ripple, faster rolloff. |
| Ripple | Chebyshev passband ripple (dB). 0.1–3 dB typical. |
| fc | Cutoff (−3 dB or ripple) frequency. |
| Z₀ | System impedance (Ω). Typically 50 Ω. |
Physical constants used
| c | Speed of light = 2.998×10⁸ m/s |
| µ₀ | Permeability of free space = 4π×10⁻⁷ H/m ≈ 1.2566×10⁻⁶ H/m |
| ε₀ | Permittivity of free space = 8.854×10⁻¹² F/m |
Inputs
1–9
dB
Ignored for ButterworthΩ
Component Values
Diagram