Constant frequency drive method for MEMS for improved failure detection

We have analyzed several automotive gyroscopes that failed during production or in vehicles. This paper discusses the analysis results and introduces a method for improved failure detection for automotive MEMS devices based on constant drive frequency. Exchanging the internal oscillation frequency of the integrated MEMS device by an external fixed frequency improves the failure detection capabilities. With our novel method we propose to reduce the complexity of the MEMS signal processing nevertheless enabling the detection of up to now undetectable slight changes of the MEMS structures. The performed electrical measurements and Finite Element Analysis simulation experiments are presented to demonstrate the feasibility of the proposed method.