Position sensing and electrostatic actuation circuits for 2-D scanning MEMS micromirror

Circuits for sensing the two-dimensional (2-D) position of a dual-axis scanning micromirror are presented together with closed-loop actuation circuits based on the phase-locked-loop for driving the resonance-mode horizontal scan. A frequency multiplexing chopper stabilization scheme is used to detect horizontal (X) and vertical (Y) position information separately from the single sensing node shared between X and Y capacitive position sensors. The circuits have been fabricated in 0.18-μm high voltage CMOS process. High-resolution 2-D position sensing and wide-angle closed-loop horizontal scanning were successfully demonstrated for the micro laser projection system.