This application note covers the extraction of signals for use with RingDown. RingDown is a prognostic method that analyzes the state of health (SoH) of a power supply or power drive system by examining the output current or voltage “signature”. For accurate prognostic and advanced diagnostic analysis, signature analysis provides a sound method of observing the level of aging and/or degradation. From this, the remaining useful life (RUL) can also be derived.