The step response of a system in a given initial state refers to the time evolution of its output when its control input is a Heaviside step function. In electrical engineering and control theory, the step response is the manifestation of a system’s output when the input changes from 0 to 1 within a very short period of time. By using this function and the impulse function, the excitation and response of dynamic circuits can be conveniently described. The impulse response is the derivative of the step response.