Conducted Electromagnetic Susceptibility Analysis Of A Typical 32 Bit Digital Signal Controller

With the development of microelectronics technology,electromagnetic compatibility of electronic devices and systems has attracted more and more attention in an increasingly complex electromagnetic environment.Integrated circuits are the core of electronic devices and systems,their electromagnetic sensitivity determines electromagnetic compatibility of the whole device and functional safety of the entire system.As a complex programmable integrated circuit chip,DSC(Digital Signal Controller)is susceptible to conducted electromagnetic interferences,which will result in the degradation or failure of system function and safety.Therefore,the study of conducted electromagnetic sensitivity on typical DSCs and achievement of low sensitivity ICs design are meaningful to enhance the electromagnetic compatibility of electronic information systems.This thesis is focused on the conducted electromagnetic sensitivity study of a typical 32-bit DSC.Based on the research methodology analysis for conducted electromagnetic sensitivity of DSCs,the electromagnetic sensitivity modelling and measurement for a specific functional unit are performed,and then a real-time protection method to reduce the electromagnetic sensitivity is in a further inquiry.The main contents are as follows:1.The research methodology of DSC conducted electromagnetic sensitivity is analyzed.In the modeling aspects of DSC conducted electromagnetic sensitivity,it is cleared that ICIM-CI(Integrated Circuit Immunity Model-Conducted Immunity)macro model is adopted after the comparative analysis of three types of electromagnetic sensitivity models.In the measurement aspects of DSC conducted electromagnetic sensitivity,it is cleared that DPI(Direct Power Injection)method is used after the comparative analysis of five standard IC immunity test methods.2.The conducted electromagnetic susceptibility model for DSC's GPIO block(General Purpose Input Output)is established.The macro modeling process is based on the analysis of functional structure and electrical characteristics of a typical 32-bit DSC chip TMS320F2812,and the detailed model is completed according to DSC chip information and S-parameter test information.Compared with the measurement results,simulation results show a great fit in the frequency of 10 MHz ~ 1 GHz,and the error does not exceed ± 4 dB.3.System clock frequency effects on electromagnetic susceptibility of DSC input buffer is given quantitatively.Conducted electromagnetic susceptibility of DSC's GPIO is measured by standard DPI method.Then considering Characterization of system clock frequency,GPIO electromagnetic sensitivity is measured repeatedly at eight different system clock frequencies.The results show that clock signal variations in frequency have an important influence on the GPIO susceptibility test,especially when high RF signal frequency is injected.The maximum variation of mean GPIO immunity levels over the whole injected RF signal frequency range(10 MHz –700 MHz)reaches 0.9 dB,the maximum GPIO immunity fluctuations over 600 MHz–700 MHz is 11.4 times than that over 600 MHz–700 MHz.4.A real-time protection method for DSC electromagnetic sensitivity is presented.In this method,embedded analogue-to-digital-convertor of DSC is regard as a sensor for electromagnetic interference,and then GPIO could dynamically adjust the software protection strategy based on the real-time monitoring results.A case study is performed efficiently based on this method without extra components,and the need of software resources is little.