Part One: Power Distribution Leads to Multiple On-Board Bus Paths

Oct 17, 2007 2:13 PM
By Lou Pechi, President, STRATA-Strategic Advisors, San Diego

Despite the warning in the popular Frank Sinatra song “Fools Rush In Where Angels Fear to Tread,” I will be very brave and attempt to look into the future of on-board power distribution trends.

Forecasting trends is like walking on ice. The closer you are to the shore, where the ice is thickest, the more solid your predictions are. As you venture further into the future, the closer you get to the center of the lake, where the ice is wafer thin. There, predictions become more precarious.

By carefully examining and then projecting trends, without stepping too far onto the thin ice, we just might catch a glimpse of the power-handling progress that will be achieved by 2020.

As we all know, power converters provide power mostly to microprocessors and integrated circuits (ICs). The trend of such ICs and microprocessors has been a continuous increase in power consumption combined with a lowering of the voltages and increases in current usage. As long as silicon is the base material for such devices, the trend will continue and devices that power them will have to accommodate their ever-greater requirements.

This in turn means that there will be an increasing need to develop higher efficiency, denser and more thermally efficient converters.

On the other hand, there’s a possibility that other methods such as optical computing could emerge. Or, perhaps there will be devices that do not require power in the way that traditional ICs do. If either of those cases comes to be, then power supplies will take quite a different direction.

I feel that within the next 20 years there is a strong probability silicon will remain the computational vehicle for IC processors. That being said, solutions to the power-conversion needs of ever-increasing power on the circuit board will have to be solved by the power-supply industry.

A distributed power architecture (DPA) — where a single voltage, supplied to several isolated dc-dc converters, generates the required lower voltages on the board — has already been replaced by an intermediate bus voltage architecture (IBA). In an IBA, a single isolated front-end dc-dc converter (DC-DC FE) provides power to multiple point-of-load converters (POLs) interspersed across the circuit board.

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© 2007 Penton Media, Inc.