Research of Microprocessor Electrical Fast Transient Pulse Group Testing

Electrical Fast Transient Pulse (EFT) is a kind of transient pulse interference caused by lightning, grounding fault or the switching of inductive load in circuit. Researchers from Cisco, Intel and other companies have proposed a model to simulate the EFT pulse coupling into the IC's power pin and input/output (I/O) pin through the EFT transient disturbance rejection direction, which is used to study the EFT disturbance rejection capability of Microcontroller unit(MCU). However, there is no failure analysis for the failed pins. This article uses a device to conduct EFT interference experiment on MCU, and analyze the failure of the faulty pin. Experiment result shows that MCU failure occurs when the coupling voltage is about 10V, and the damage is about 30V.According to the analysis of the experimental results, during the EFT test process, the power supply pins start to fail when the coupling voltage is very small and the voltage when burning is also small, which has a great impact on the EFT performance of the entire MCU. Therefore, it is necessary to consider the protection of I/O pins and strictly design the EFT protection structure of MCU.