This paper describes an interface circuit for a MEMS Coriolis mass flow sensor that combines both drive and sense circuitry. The MEMS sensor consists of a suspended resonant tube, which is read-out by comb capacitors and driven into oscillation by current flowing through a drive coil in a magnet field. The interface circuit comprises a low-noise front-end that performs capacitance-to-voltage (C/V) conversion, and a drive-loop with automatic amplitude control. Drive motion can also be detected from the output of the front-end, allowing both drive and sense functions to be combined. The front-end is chopped to mitigate its 1/ f noise. When implemented with commercial off-the-shelf (COTS) components, the proposed interface draws 250 mA from a single 5-V supply. Mass flow measurements with Nitrogen gas (N2) show that the sensor's drive frequency drifts by less than 1 mHz (rms) per hour, while its zero stability is less than 2.6 mg/h during an 80s measurement.

Original languageEnglish
Title of host publication2019 IEEE Sensors, SENSORS 2019 - Conference Proceedings
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Number of pages4
Volume2019-October
ISBN (Electronic)9781728116341
DOIs
Publication statusPublished - 1 Oct 2019
Event18th IEEE Sensors, SENSORS 2019 - Montreal, Canada
Duration: 27 Oct 201930 Oct 2019

Conference

Conference18th IEEE Sensors, SENSORS 2019
CountryCanada
CityMontreal
Period27/10/1930/10/19

    Research areas

  • Coriolis, gyroscopic, mass flow, MEMS, sensor interface

ID: 69713160