A ring-down technique implemented in CMOS-MEMS resonator circuits for wide-range pressure sensing applications

Abstract

In this work, a 1.2-MHz CMOS-MEMS DETF (double-ended tuning fork) resonator with its on-chip tunable transimpedance amplifier (TIA) is designed to measure the ring-down response of the resonator circuit for pressure sensing applications. From the time-domain ring-down waveform, the frequency and quality factor of the resonator circuit can be extracted corresponding to its environmental pressure. Due to the effect of the squeezed-film damping caused by environmental pressure, the quality factor would change accordingly, thus affecting the waveform of the ring-down characteristic. By measuring the ring-down response under various pressure levels, the designed resonator circuit features a wide pressure sensing range from 0.8 Torr to 220 Torr.