Disclosed herein is a circuit for determining failure of a movable MEMS mirror. The circuit includes an integrator receiving an opening angle signal representing an opening angle of the movable MEMS mirror, and a differentiator receiving the opening angle signal. A summing circuit is configured to sum the integrator output and the differentiator output. A comparison circuit is configured to determine whether the sum of the integrator output and differentiator output is not within a threshold window. An indicator circuit is configured to generate an indicator signal indicating that the movable MEMS mirror has failed based on the comparison circuit indicating that the sum of the integrator output and differentiator output is not within the threshold window.