Several alternatives for low output voltage on board converters

Abstract

This paper shows several approaches to generate low output voltage (3.3 V and 1.5 V) through on board converters. They all are supplied from a DC voltage ranging between 3 V and 6 V (valid for 5 V or 3.3 V input). With such low input and output voltages, synchronous rectification is mandatory to keep efficiency at reasonable levels. Magnetic components play a key role when Self Driven Synchronous Rectification (SDSR) is used. Several technologies have been used to build them, namely standard multilayer PCB, specific flex foils and thick film on ferrite. Three prototypes have been built using these technologies.