Frequência de Ressonância LC
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
f = 1/(2π√LC)
About this calculator
The LC Resonance Frequency Calculator determines the natural oscillation frequency of an LC circuit, composed of an inductor (L) and a capacitor (C). The resonant frequency is where inductive and capacitive reactances are equal, leading to maximum energy transfer. The formula used is f = 1/(2π√(LC)), where f is frequency in hertz, L inductance in henrys, and C capacitance in farads.
This calculator is essential for designing radio frequency circuits, filters, oscillators, and communication systems. For example, when tuning a radio, you adjust the capacitor so that the resonant frequency matches the desired station. It is also used in switched-mode power supplies and impedance matching circuits.
Important precautions: units must be in SI (henrys and farads) for correct results. Very small or large values require scientific notation (e.g., 1e-6 for micro). The formula assumes ideal components without resistance; in real circuits, resistance reduces frequency and amplitude at resonance.
Frequently asked questions
What is the resonant frequency in an LC circuit?
It is the frequency at which the circuit naturally oscillates, with maximum energy transfer between the capacitor and inductor.
How does resistance affect the resonant frequency?
Resistance slightly reduces the resonant frequency and decreases the oscillation amplitude, but the ideal formula ignores this effect.
Can I use units like microhenrys and picofarads?
Yes, but convert to henrys and farads before using the formula. Example: 10 μH = 10e-6 H, 100 pF = 100e-12 F.
What is the practical application of resonant frequency?
It is used in radios to tune stations, in filters to select frequencies, and in oscillators to generate signals.
What happens if L or C is zero?
If L or C is zero, the circuit does not oscillate; the frequency tends to infinity, but in practice there is no resonance.