A Comparison of Two Excitation Modes for MEMS Electrothermal Displacement Sensors

作者：Mohammadi Ali^*; Moheimani S O Reza; Yuce Mehmet Rasit

来源：IEEE Electron Device Letters, 2014, 35(5): 584-586.

DOI：10.1109/LED.2014.2313291

• Micro-electromechancial systems (MEMS)
• electrothermal sensor
• noise

MEMS electrothermal displacement sensors can be operated in constant current (CC) or constant voltage (CV) excitation modes. The CV mode is more commonly used. However, there have been reports that the CC excitation mode may lead to a larger measured signal, and thus, it may be a better choice than the CV mode. In this letter, we present an analytic comparison of the two methods, and show that from a signal-to-noise-ratio point of view, benefits of operating a sensor in CC mode are only marginal. The analytical investigation is supported by experiments performed on sensors integrated in a SOI-MEMS nanopositioner with low noise read out circuits, which leads to 0.04-nm/root Hz displacement resolution for both excitation modes.

• 出版日期2014-5