Precision readout circuits for capacitive microaccelerometers


Yazdi N., Kulah H., Najafi K.

IEEE Sensors 2004 Conference, Vienna, Austria, 24 - 27 October 2004, pp.28-31 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume:
  • Doi Number: 10.1109/icsens.2004.1426091
  • City: Vienna
  • Country: Austria
  • Page Numbers: pp.28-31
  • Keywords: capacitive sensor readout circuit, MEMS accelerometer, interface, micro-g accelerometer, INTERFACE, CHIP

Abstract

This paper presents a review of capacitive readout front-end circuits for high-precision accelerometers. The primary design parameters and the trade-offs affecting the resolution are presented. The discussions apply to all capacitive microsensor interfaces. Also a high-sensitivity capacitive accelerometer interface circuit for hybrid-integration with a surface/bulk micromachined micro-g accelerometer is described [7, 10]. The first generation of the circuit resolves 75aF of capacitance on similar to 120pF parasitic capacitance with a 200kHz sampling rate, and the second generation resolves 20aF with 1MHz sampling rate. The overall sensor-circuit module has a noise floor of 1.6 mu g/root HZ at ambient atmosphere.