Electrical fast-transient test: Conducted and radiated disturbance determination by a complete source modeling

Tests against electrical fast transient/burst (EFT) represent a serious thr eat for modern high-speed electronics: besides the conducted injection of h igh amplitude pulse, a strong radiated held is produced during this test. T he prediction of the effects of this test during the equipment early design stage requires the equivalent circuit of the generator: the output wavefor m into a resistive 50-Omega load is not sufficient to recover the complete circuit, including inductive component and parasitic elements. These are es sential to predict the disturbance produced in arbitrary loads, as the equi pment under test can be viewed. This paper describes how to characterize the EFT generator by means of the measurement of the output voltage and current produced in presence of known loads; moreover, a procedure to calculate the current an the equipment pow er cord is shown, based on the use of a circuit simulator (PSPICE). Finally , the disturbance produced on different loads and the radiated held during the test are calculated and experimentally validated.