Upgrading the ICIM-CI Model to Account for Amplitude-Modulated Interference Signals

This article presents a methodology for extracting the integrated circuit immunity model–conducted immunity (ICIM-CI) model of an electronic circuit, specifically to account for amplitude-modulated (AM) interference signals. The device under test (DUT) is a voltage follower circuit based on an operational amplifier. When its input is subjected to AM interference, the output voltage varies in accordance with the interference envelope. It is shown that the amplitude of the DUT’s output voltage depends on the modulation frequency of the interfering signal. To capture this dependence, the direct power injection test bench has been modified to inject hypoband and mesoband interference signals. This setup allows the extraction of a transfer function describing the dependence of the DUT’s output amplitude on the modulation frequency. This transfer function is then used to enhance the ICIM-CI model of the DUT, enabling accurate simulation of its behavior under exposure to AM interference signals.