When using conventional buck regulator to step down a 48 V intermediate voltage rail, the conversion becomes less efficient as the output voltage gets much lower.
Example, converting 48 V to 5 V requires a duty cycle of only about 9.6%. This low duty cycle can result in moderate conversion efficiency and higher power losses
With a transformer-based architecture, such as a push-pull or forward converter, the duty cycle can be adjusted by the winding ratio of the transformer. This would allow the conversion to take place more efficiently if it weren’t for the additional losses caused by the transformer. Especially in applications that do not require galvanic isolation, one would like to do without a transformer.
In applications where efficiency and power density are important, an alternative topology can offer a better solution.
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