March 13, 2008 -- The semiconductor industry has always forced the power-supply industry to follow its trendsetting lead. For the last decade, that trend has been to cram more transistors into a single package, particularly microprocessors. This led to microprocessors with smaller feature sizes and tighter spacing between internal components. To be operational, smaller feature sizes forced the processors to operate at a lower voltage. This, in turn, required lower voltage power supplies with greater design challenges than their predecessors of five to 10 years ago.

Designers can deliver low-voltage, high-current microprocessor supplies. But when you add the requirement for high efficiency (90% or better), the technology falls a bit short. It’s unlikely that the high-efficiency requirements can be met using present-day components and technologies, but it can reach about 70% to 80%.

By Sam Davis, Electronic Design Contributing Editor