Designing High-Efficiency Switched-Mode Power Supplies Using Advanced MOSFETS

摘要

Switch-mode power supply designers can take of advanced power MOSFETs that fea-low on resistance and fast switching speeds, ut to do so, they may need to select their circuit topologies and components in a way that yields optimal results. Take for instance, a power supply designed to deliver approximately 2 KW of output power at 48 V, a type that is commonly used in mobile phone base sta-tions (Figure 1). Using conventional bipolar power switches operating at a switching frequency of 80 kHz, such a design may require fast-recovery epitaxial diodes (FREDs) as the output rectifiers. Often, however, this requirement results in designs not optimized for any one parameter of their specification. In this case, the result is at best a compromise among key parameters.