Influence of Radio Frequency Interference on the Electromagnetic Emission of Integrated Circuits

An important prerequisite for ensuring the safe operation of vehicles is compliance of electronic systems with electromagnetic compatibility (EMC). To ensure compliance with the applicable EMC regulations, a wide variety of EMC tests, such as checking compliance with electromagnetic emission limits or ensuring a sufficiently high immunity to interference signals, are performed on integrated circuits (ICs) and electronic systems. In most cases, however, these tests are performed in sequence and each result is evaluated separately. A possible mutual influence of the test procedures is usually not taken into account. In this article, we discuss how radio frequency disturbances can affect the generated electromagnetic emission of an IC. Therefore we propose a simple test method which is based on the direct power injection (DPI) characterization method according to IEC 62132 and the 150-Ohm method according to IEC 61967. We show, how the operating state of ICs is changed by an interference signal, such that electromagnetic emission limits are exceeded and in addition the ICs do not fulfill the functional requirements anymore.