The Research On The Reverse Recovery Mechanism Of A PIN Diode

Since the1950s, the silicon diode began to be used in power electronic field, howeverthe diode in modern power electronics always underestimated the role, especially in theinverter circuit and frequency conversion circuit. The reverse recovery characteristics ofthe diode is very important in power electronic field, so It needs to be further research.In this paper, at first PIN diode reverse recovery mechanism was detailed analysis, thePIN diode shutoff physical process was thorough research, the establishment of a PINdiode reverse recovery process step calculation model was deduced, the reverse recoveryprocess calculation model in each stage of time calculation formula, and in some simplifiedapproximation, based on the sum up for reverse recovery time calculation formula by usingthe simplified formula of analysis on the PIN diode reverse recovery time and softnessfactor and dynamic avalanche breakdown factors. Implemented the PIN diode fast softrecovery conditions: make the minority carrier life increase with the distance from the PNjunction can increase the softness factor; make the PN junction nearby non-equilibriumcarrier concentration reduce can reduce the reverse current peak; reasonable reduce thebase zone width and minority carrier life can reduce the reverse recovery time.Then using silvaco established the analysis of the PIN diode reverse recovery processof the device structure model and simulation circuit simulated the PIN diode reverserecovery current and reverse recovery time and softness factor, analyzed the reverserecovery process in each stage intrinsic area carrier distribution, and verified the timecalculation formula of the rationality which was simplified approximation. Simulated theimportant influence factors of the PIN diode reverse recovery time was the forward currentdensity, the intrinsic area carrier life, the width of the intrinsic zone and the K value fourinfluence factor. Got the reverse recovery time and softness factor with the influencefactors of the change trend, verified the reduced reverse recovery peak current and reverserecovery time, and increased the softness factor to realize soft recovery methods, laid thefoundation for reasonable design the related parameters of the PIN diode.