Second‐Order RLC Circuits Overview

Summary

Second‐order circuits have two reactive circuit elements, which store energy. Circuits with an inductor and capacitor together, where they can exchange energy, are second‐order circuits. Second‐order RLC circuits have a resonant frequency where impedances and frequency responses exhibit peak values, maximum or minimum. Ordinary differential equations, with respect to time, describe lumped element circuits and second‐order differential equations describe second‐order RLC circuits in the time domain. Transfer functions are commonly used to quantify the input‐output characteristics of circuits in the steady‐state frequency domain, using phasor quantities. Two main time domain response analyses are natural response and step response, where natural response is undriven and step response is driven. Natural response is also called zero‐input response and step response is one type of zero‐state response.