Differential wide temperature range CMOS interface circuit for capacitive MEMS pressure sensors

Yucai Wang; Vamsy P Chodavarapu

doi:10.3390/s150204253

Differential wide temperature range CMOS interface circuit for capacitive MEMS pressure sensors

Sensors (Basel). 2015 Feb 12;15(2):4253-63. doi: 10.3390/s150204253.

Authors

Yucai Wang¹, Vamsy P Chodavarapu²

Affiliations

¹ Department of Electrical and Computer Engineering, McGill University, McConnell Engineering Building, 3480 University Street, Montreal, QC H3A 0E9, Canada. yucai.wang@mail.mcgill.ca.
² Department of Electrical and Computer Engineering, McGill University, McConnell Engineering Building, 3480 University Street, Montreal, QC H3A 0E9, Canada. vamsy.chodavarapu@mcgill.ca.

Abstract

We describe a Complementary Metal-Oxide Semiconductor (CMOS) differential interface circuit for capacitive Micro-Electro-Mechanical Systems (MEMS) pressure sensors that is functional over a wide temperature range between -55 °C and 225 °C. The circuit is implemented using IBM 0.13 μm CMOS technology with 2.5 V power supply. A constant-gm biasing technique is used to mitigate performance degradation at high temperatures. The circuit offers the flexibility to interface with MEMS sensors with a wide range of the steady-state capacitance values from 0.5 pF to 10 pF. Simulation results show that the circuitry has excellent linearity and stability over the wide temperature range. Experimental results confirm that the temperature effects on the circuitry are small, with an overall linearity error around 2%.