Detection of Electromagnetic Interference in Microcontrollers Using the Instability of an Embedded Phase-Lock Loop

This paper presents a combined hardware-software mechanism for the detection of electromagnetic interference of a microcontroller (μC) in daily usage. This detection mechanism is based on the instability of phase-lock loop embedded in the target μC. It can detect the presence of EMI with higher sensitivity than polling the hardware status of the μC internal registers and thus provides a better detection margin within the 10 kHz to 1 GHz EMI frequency range. Despite its relative slowness and its resource consumption, it is very robust, can be implemented in virtually any application software, and does not require any electromagnetic compatibility test equipment.