A Sub-mW 18-MHz MEMS Oscillator Based on a 98-dB Ω Adjustable Bandwidth Transimpedance Amplifier and a Lamé-Mode Resonator

Anoir Bouchami; Mohannad Y Elsayed; Frederic Nabki

doi:10.3390/s19122680

A Sub-mW 18-MHz MEMS Oscillator Based on a 98-dB Ω Adjustable Bandwidth Transimpedance Amplifier and a Lamé-Mode Resonator

Sensors (Basel). 2019 Jun 13;19(12):2680. doi: 10.3390/s19122680.

Authors

Anoir Bouchami¹, Mohannad Y Elsayed², Frederic Nabki³

Affiliations

¹ Department of Electrical Engineering, École de technologie supérieure, Montréal, QC H3C 1K3, Canada. bouchami.anoir@courrier.uqam.ca.
² Department of Electrical Engineering, École de technologie supérieure, Montréal, QC H3C 1K3, Canada. mohannad.elsayed@mail.mcgill.ca.
³ Department of Electrical Engineering, École de technologie supérieure, Montréal, QC H3C 1K3, Canada. frederic.nabki@etsmtl.ca.

Abstract

This paper presents a microelectromechanical system (MEMS)-based oscillator based on a Lamé-mode capacitive micromachined resonator and a fully differential high-gain transimpedance amplifier (TIA). The proposed TIA is designed using TSMC 65 nm CMOS technology and consumes only 0.9 mA from a 1-V supply. The measured mid-band transimpedance gain is 98 dB Ω and the TIA features an adjustable bandwidth with a maximum bandwidth of 142 MHz for a parasitic capacitance C P of 4 pF. The measured input-referred current noise of the TIA at mid-band is below 15 pA/ Hz . The TIA is connected to a Lamé-mode resonator, and the oscillator performance in terms of phase noise and frequency stability is presented. The measured phase noise under vacuum is -120 dBc/Hz at a 1-kHz offset, while the phase noise floor reaches -127 dBc/Hz. The measured short-term stability of the MEMS-based oscillator is ±0.25 ppm.

Keywords: 1-dB compression point; Lamé-mode MEMS resonator; MEMS-based oscillator; electrostatic actuation; input-referred noise; phase noise; quality factor; transimpedance amplifier.