Micro-Electro-Mechanical Systems (MEMS) resonators have gained widespread application in high-precision sensors across various industries, including wearable devices,
automotive systems, and consumer electronics. This popularity stems from their advantages such as high precision, high resolution, small size, and ease of integration. However, despite these advantages, the circuit designs for MEMS resonators—specifically the
sustaining oscillator circuits—have remained largely unchanged for decades. Traditional
excitation methods have faced limitations, particularly in terms of low output amplitude
and restricted linearity of the MEMS devices. These constraints present challenges in improving the overall performance of MEMS resonator-based sensors, making the search
for new excitation methods a crucial area of research.
Recently, a novel excitation scheme called Blue Sideband Excitation(BSE) has been
proposed, which can simultaneously excite multiple modes of the MEMS resonator and
significantly enhance output amplitude and sensor sensitivity. This new method opens
the door to substantial performance improvements for MEMS-based sensing applications, however, there has been little research on it so far.
The goal of this project is to develop a sensor interface based on the BSE technique
for MEMS resonators. The proposed interface incorporates a transimpedance amplifier
(TIA), a phase-locked amplifier, and an automatic amplitude control module. This paper presents a comprehensive theoretical analysis, detailed design specifications, and
performance testing of the interface.It is the first on chip sensor interface based on BSE.
The final implementation is set to undergo tape-out in April 2024.