Reliability Calculation Method for Output Capacitor Bank used in Telecom Power Supplies

This paper evaluates reliability of a power supply. For a telecom power supply, the capacitor bank accounts for the most of the failure rate. A complete calculation is provided herein based on IEC TR 62380 standard. This is a reliability data handbook for prediction on electronics components, PCBs and equipment, which has the advantage of taking directly into account the influence of the environment with calculation models. Thus, thermal cycling seen by components is function of equipment mission profile and replaces previously used environment factor, often having a difficult evaluation. Finally, the paper compares results from calculation with MIL-HDBK217 and IEC TR 62380.