A systematic approach for reliability assessment of electrolytic capacitor-free LED drivers

Abstract

In this paper, a systematic approach for reliability assessment of electrolytic capacitor-free LED drivers is developed to investigate the failure rate of MOSFETs in the drivers. An original fly-back driver with electrolytic capacitor and two modified electrolytic capacitor-free drivers are studied, and their performances are compared. Due to LED lumen depreciation during operation, current of the MOSFET decreases over time, which cancels out the effect of junction temperature increase. As a result, the junction temperature of MOSFET increase mildly for the case study, but failure rate is accelerated.