DC/DC Converter Output Capacitor Bank's Reliability Comparison using Prediction Standard MIL-HDBK-217F and IEC 61709

When it comes of reliability many studies has shown that the output capacitor bank is demonstrated to be the most critical component [7,9,10,13]. A higher level of reliability became a compulsory demand in modern DCDC converters [7]. In this work, the failure rate of an output capacitor bank used within a high current low voltage buck converter is calculated with both the latest prediction standard IEC 61709-2017 and the older standard MIL-HDBK-217, providing a comparison between the two which is a helpful tool for the output capacitor selection in the early stage design. This newer standard is trying to make compensation of the lack of the newest component technology in older standards.The components' environmental conditions were defined by a standard buck converter POL used for both calculation methodologies [4,5]. Results are compared by taking account of the influence of component's temperature and application of specific concepts like references conditions, operating conditions, ripple capability, internal selfheating.