Study of aging time effect on the EMI evolution of power RF LDMOS transistor in DC-DC buck converter circuit

Recent studies have shown that the aging time effect on power RF LDMOS transistor may modify electromagnetic emission significantly. It is even rarer to use of RF LDMOS (Radio Frequency Lateral Diffused Metal–Oxide–Semiconductor) devices in a power application. This paper reports on an experiment that prove to elucidate the origins of level changes in the Electro-Magnetic Interference (EMI) in DCDC buck converter. In addition, their influences on the electrical parameters and their relationship with charge trapping at the interface are studied. The experimental results (spectre and waveform parameters), obtained after various thermal aging times are presented and discussed. The experimental results have highlighted that there is an increase in the amplitude of resonances on the interference spectra after aging. The level changes are proportional to the aging time. The charge trapping in gate oxide caused Miller capacity value to decrease (C
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), thereafter in turn a decrease in the level of disturbance.