Proposed Switching Losses Model for Integrated Point-of-Load Synchronous Buck Converters

Nowadays, point-of-load (POL) converters´ investments are counted as a main part in power management markets; especially the synchronous buck converters. Today´s products forces designers to highly integrate POL converters by increasing the switching frequency; so the latest technology has used megahertz range to obtain this target. On the other hand, increasing switching frequency means increasing the switching losses. Therefore, it is very important to optimize the operating switching frequency tradeoff, which requires an accurate model taking in consideration the converter operating conditions. This paper presents an accurate mathematical loss model taking in consideration the physical behavior of the MOSFET switch in addition to the converter operating conditions. This model introduces accurate equations for every switching intervals and so accurate loss calculations. An integrated POL synchronous buck converter of 5 MHz, 5-1.8 V/3 A prototype is fabricated. The results of the proposed model are compared with simulation and experimental results under variable operating conditions. Good matching between the mathematical, experimental, and simulation results are obtained.