A MEMS interface IC with low-power and wide-range frequency-to-voltage converter for biomedical applications

Md Shamsul Arefin, Jean-Michel Redoute, Mehmet Yuce

Research output: Contribution to journalArticleResearchpeer-review

11 Citations (Scopus)

Abstract

This paper presents an interface circuit for capacitive and inductive MEMS biosensors using an oscillator and a charge pump based frequency-to-voltage converter. Frequency modulation using a differential crossed coupled oscillator is adopted to sense capacitive and inductive changes. The frequency-to-voltage converter is designed with a negative feedback system and external controlling parameters to adjust the sensitivity, dynamic range, and nominal point for the measurement. The sensitivity of the frequency-to-voltage converter is from 13.28 to 35.96 mV/MHz depending on external voltage and charging current. The sensitivity ranges of the capacitive and inductive interface circuit are 17.08 to 54.4 mV/pF and 32.11 to 82.88 mV/mH, respectively. A capacitive MEMS based pH sensor is also connected with the interface circuit to measure the high acidic gastric acid throughout the digestive tract. The sensitivity for pH from 1 to 3 is 191.4 mV/pH with 550 µ Vpp noise. The readout circuit is designed and fabricated using the UMC 0.18 um CMOS technology. It occupies an area of 0.18 mm2 and consumes 11.8 mW
Original languageEnglish
Pages (from-to)455 - 466
Number of pages12
JournalIEEE Transactions on Biomedical Circuits and Systems
Volume10
Issue number2
DOIs
Publication statusPublished - 2016

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