Abstract : This paper describes the electromagnetic interference (EMI) protection of DSP frequency converters, including the hardware of interface circuits, bus, printed circuit board EMI protection measures, and power output EMI compatibility design. Software anti-interference includes using traps to prevent the spread of out-of-order phenomena caused by interference, using time redundancy to shield interference signals, and specific coding fault tolerance, instruction redundancy, flag method and digital filtering techniques. Keywords : frequency converter; electromagnetic interference; hardware anti-interference; software anti-interference [b][align=center]Anti-Electromagnetic Interference Based on DSP Transducer LU Fan-xing, LIU Yong, Li Zhen-kai, LU Yi-min (1. Academy of Applied Science, Jiangxi University of Science & Technology, Ganzhou 341000, China; 2. Dept. of Electron & Information, Huazhong University of Science & Technology, Wuhan 430074, China)[/align][/b] Abstract: Based on DSP transducer, hardware of anti-electromagnetic interference includes interface circuit, bus, anti-jamming measure of printed circuit board, and electromagnetic compatible design of power output. Software anti-jamming design includes using traps to prevent desequencing expansion; adopting time redundancy to screen jamming signals; special coding fault tolerance; instruction redundancy; symbol method; digital filtering; and so on. Keywords: Transducer; Electromagnetic interference; Hardware anti-jamming; Software anti-jamming 0 Introduction Electromagnetic interference sources are divided into conducted interference sources and conducted electromagnetic noise interference sources. Conducted interference sources refer to interference from useless information on analog channels. Conducted electromagnetic noise interference sources are interference from electromagnetic noise without information on the frequency converter system. Conducted electromagnetic interference transmission channels are divided into capacitive, resistive, and inductive conductive coupling. Capacitive conductive coupling refers to electromagnetic conductive coupling formed by the capacitive linkage between the interference source and the signal transmission line through wires and components. Resistive conductive coupling refers to conducted electromagnetic coupling formed by the current or voltage linkage on a common impedance between the interference source and the signal transmission line, i.e., magnetic field coupling. In DSP-based digital frequency converters, resistive and inductive conductive coupling are particularly prominent. This includes the impact of transient pulse interference on digital circuits, the effects of distributed inductance and capacitance on signals, and the impact of power supply on the system. This section discusses electromagnetic interference (EMI) based on DSP frequency converters and its solutions. [b][align=center]For more details, please click: Electromagnetic Interference Immunity Based on DSP Frequency Converters[/align][/b]