Precursor parameter identification for power supply prognostics and health management

Prognostics and health management (PHM) seeks to identify and isolate reliability problems in products (diagnostics) and predict a product's remaining useful life (prognostics). In this paper, a four-step PHM approach for power supplies is presented: 1) precursor parameter identification based on historical data analysis and failure mechanism analysis; 2) baseline establishment by conducting experiments under different environmental and usage conditions and characterizing precursor parameters for healthy power supplies; 3) baseline verification by conducting similar experiments for fielded power supplies; and 4) testing. Precursor parameter identification for one switch-mode power supply (SMPS) was carried out. The power metal-oxide semiconductor field-effect transistor, insulated-gate bipolar transistor, and the Schottky diode were identified as the majority cause by historical data analysis. Gate oxide leakage current, threshold voltage, transconductance, junction temperature, VCE (on), and contact resistance were determined to be monitored parameters for this SMPS after a failure mechanism analysis.