Application specific efficiency improvement for an industrial point of load converter

Today, many electrical applications use the DC-DC buck converter topology as point of load (POL) converter with synchronous rectifiers to provide the desired output voltage for different loads and components [1–3]. While its efficiency is usually optimized for high output powers, in case of low and mid power it is often off the optimum. Nevertheless, since many applications force these converters to operate at part load condition most of the time, the system´s overall power consumption can be reduced noticeably by optimizing the efficiency at its main operating point. This paper deals with the specific efficiency improvement of an existing industrial POL converter (Po,max = 60 W) towards its main operating point at part load with Po = 15 W. In a first step, the converter is analyzed in the time-domain by means of a sampled data modeling (SDM) approach in order to simulate and predict its behavior as accurate as possible. In a second step, based on the derived converter model the POL is optimized for Po = 15 W by simulations using the SDM model. Finally, practical measurements are performed in order to verify the correctness of the identified options for improvements.