A Viable Nontesting Method to Predict the Lifetime of LED Drivers

As the weakest links in light-emitting diode (LED) luminaires, LED drivers dominate the luminaire lifetime. This paper proposes a viable method to predict the reliability and lifetime of LED drivers. It obtains the failure rate of LED drivers using part stress analysis based on the failure rate models provided in MIL-HDBK-217F N2 (MIL) and then uses the Weibull distribution model to estimate the lifetime of LED drivers. In order to improve the accuracy, the original failure rate models in MIL of the dominant components, such as aluminum electrolytic capacitors, are replaced with more accurate models. As an experimental verification of the proposed method, the lifetime estimation from accelerated life testing (ALT) is also presented. The lifetime profile of a quasi-flyback LED driver based on 24/7 operation is obtained using the proposed method and compared with the ALT result. The consistency between the two methods well demonstrates the effectiveness and accuracy of the proposed method.