Analysis of sensor disturbances caused by IEMI

Abstract

Sensors are the link between the digital and the analog world. They can be found in almost all electronic systems and provide the system with access to environmental data. The disturbance of such enviromental data can have serious consequences. For example, an oil pressure sensor on a U.S. Navy ship was disturbed by an RF signal in such a way that a shutdown signal in the automatic power control system was triggerd. Likewise, some early ABS systems in Germany were affected by a radio transmitter in such a way that there were severe problems with the brakes in certain highway sections [3]. Although sensors systems are susceptible to interference, there is insufficient research on the susceptibility of sensors systems to interference. There are studies on the susceptibility of microelectromechanical systems (MEMS) to acoustic signals [7, 8]. However, it was pointed out in [5] that electromagnetic interference is generally not explicitly addressed or even neglected in sensor design. In our previous work [4] we have shown that a MEMS sensor with Inter-Integrated Circuit (I²C) interface can be disturbed by electrical fields. The effects include communication breakdowns, controller crashes, short term and permanent sensor value errors. In [2], similar errors are reported for two other sensors with I²C interface. In this work, we focus on the cause of the observed interference by localizing the interference susceptibility and analyzing the I²C communication. First, the measurement setup and the sensors used are presented in Section 2. The measurement results are shown in Section 3. Finally, in Section 4 we give a short conclusion and an outlook.