Research On Mechanism Of Fast Jamming Pulse Group Effect Of Microcontroller

Microcontroller are widely used in various electronic devices due to their advantages of small size,strong performance and high integration.However,because of these advantages,the phenomenon of mutual electromagnetic interference of microcontrollers is becoming more and more serious,resulting in a greatly reduced electromagnetic compatibility of microcontrollers.Therefore,studying the electromagnetic compatibility robustness of microcontrollers is very important for microcontroller manufacturers and enterprises electronic systems are particularly important.As a typical transient pulse,Electrical Fast transient(EFT)has the characteristics of high amplitude and fast voltage rise,which has a great impact on the performance of microcontrollers.Therefore,the research on the mechanism of the micro-controller’s fast interference burst effect is of great significance for analyzing the electromagnetic compatibility performance of integrated circuits.In this paper,a microcontroller widely used in the market is used to conduct EFT burst experiments,establish a model of microcontroller anti-EFT immunity,and explore the failure mechanism of microcontroller under EFT interference.Firstly,it introduces the research background,the related content of integrated circuit electromagnetic compatibility,the harm of EFT pulse and the current research status at home and abroad.Next,describe the internal functions of the microcontroller to be tested,design the PCB board for the EFT experiment,build the EFT anti-interference test system,and then select the power supply pins,crystal oscillator pins,clock pins and other injection pins of the microcontroller The EFT effect study was carried out to analyze its reliability under different EFT interference voltages.Then,the S-parameters of the power distribution network and load configuration of the microcontroller are extracted by a vector network analyzer,and converted into an equivalent RLC circuit.Then,a complete microcontroller EFT immunity model is established.The simulation and experimental results show that:(1)The EFT test voltage of the microcontroller pin increases,and the failure phenomenon becomes more and more serious,but some pins,such as the crystal oscillator pin,because the protection structure of the pin is turned on,which leads to the failure of a certain pin.The voltage is more sensitive,and this rule does not appear;(2)The anti-interference model of the microcontroller has a high degree of fit with the experimental results,and it can predict the internal voltage waveform and failure level of the microcontroller when the EFT pulse interference enters the pin;(3)On the one hand,the reason for the failure of the pin may be that the internal digital signal changes due to the external interference of the power supply voltage,and the wrong signal is sent to the receiver of the microcontroller,resulting in the failure or incompleteness of the microcontroller function.On the other hand,the complementary components in the device caused by metal oxide semiconductor latch-up.Finally,according to the influence of EFT pulse interference on the microcontroller,the waveform test,I-V curve inspection,X-ray inspection,electron microscope scanning and other inspections were carried out to analyze the failure cause of the microcontroller,and the measures against latch-up effect were proposed.