This project focuses on designing a microcontroller compensated circuit for a thin-film piezoelectric on silicon microelectromechanical systems (MEMS) oscillator. MEMS oscillators have an advantage over traditional crystal oscillators in the sense that they can be fabricated using conventional semiconductor fabrication methods and can often be smaller in size. However, these MEMS oscillators vary in performance depending on ambient temperature. For this reason, this project focuses on designing a printed circuit board that will keep the resonator at a steady resistance (directly related to temperature) to stabilize and optimize the performance of the device. Oven-control circuits for MEMS oscillators have been created before; however, this one is unique because it will use a thin-film piezoelectric on silicon (TPoS) oscillator that is a subject of research for the project sponsor, Dr. Reza Abdolvand.

To keep the resonator temperature stable, current is passed through it to elevate its temperature beyond the industrial temperature limit using Ohmic resistive heating. Since the temperature and resistance of the device are directly related, the resistance of the resonator is controlled with a microcontroller and set via user input. The microcontroller was programmed to implement a control loop to keep the resonator’s resistance stable.