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by ericbarrett 1924 days ago
48V DC has always been the standard for DC-fed rack mount servers as far as I am aware. Telcos have used -/+ 48V since A. G. Bell.
1 comments

Yes, but single-stage conversion from 48 V to ~1.2 V core/memory voltages is inefficient with the typical buck topology, due to the low duty cycle.

There are solutions based on ZCS (+ZVS) (semi-)resonant switched capacitor topologies that could (technically) do this in essentially one stage. But because they are still somewhat recent and rely on either GaN enhancement-type FETs or low-average-blocking-voltage topologies that make use of e.g. small 5V-capable IC process nodes and some tricks to have the individual power transistors floating.