Steve L. Garverick
Department of EECS, Case School of Engineering
In this research, we are developing integrated circuit technology for MEMS-based, wireless microsensors for operation in harsh environments, especially high temperature. This presentation features a capacitance-to-voltage converter IC that combines correlated double sampling with delta modulation in a fully differential circuit to achieve a low-noise, sensor interface circuit with user-selectable gain and bandwidth. Dynamic tests of the IC yielded 0.16% nonlinearity, 190-aF resolution, and 68-dB dynamic range at 6-ksps sample rate.
The IC was used to evaulate a silicon carbide MEMS resonator, which demonstrated
a Q of 51 at 760 Torr, increasing to 6900 at 175 mTorr. Such resonators are
being studied for potential application as sensors, as as frequency reference
for communication and data acquisition circuits operating in high-temperature
environments.