Study On The ESD EMP Effects And Preventing Techniques Of CPLD System

With the rapid development of electron technology, the harm and potential menace of Electro-Static discharge (ESD) to electronic device and system become more serious and difficult to control. In this paper, the failure effect that caused by Electro-Static discharge Electromagnetic Pulse (ESD EMP) and protective techniques in CPLD system are researched, And the major contents of this paper can be summarized as follows:Based on the analysis of current station and problem about ESD caused disturbance and coupling path to electron system,ESD protective method at home and abroad, the characteristic of ESD EMP is analyzed and the primary reason of system disturbance caused by ESD is summarized, such as:the current of ESD directly access to circuit is the failure cause of system; through the break-over path caused by stray capacitance, ESD current can couple to circuit to destroy system; ESD current coupled to systemt through by the capacitance and inductance of adjacent circuit during transmission, ESD current can generate potential difference when flow through chassis to disturb the circuit ground wire; the second discharge between circuit and chassis can lead circuit accident; interconnected equipment can influence each other, and so on.A CPLD system for carrying out ESD EMP effect experiment have designed, associated with the standard of IEC61000-4-2 about ESD immunity test platform, and take irradiation effect experiment by the method of indirect discharge, the threshold voltage when appear system failure is obtained, then the law of system under ESD EMP effect is summarize by analyzing the reason of problem.The interference's mechanism of ESD EMP on system was analyzed, and the method of anti-interference in system was summarized:grounding technology,masking techniques,suitable overlap,piezoresistor,transient voltage suppressor,integrated electrostatic protected device and so on. Based on the failure effect experiment, combining the A/D conversion error module, and several effective reinforcement of ESD in system was comparative analyzed by the test in lab. It comes to the conclusion that ESD protection of future is software forecast.