Digital Power
By Staff -- EDN, September 18, 2008
Digital power comprises two different capabilities: The first and relatively simple, capability, digital communication, allows a system host to monitor and control the power subsystem. The second, and much more complex capability, is closing the power feedback loop digitally. Proponents of the well-established analog feedback loop disparage digital power loop control as being complex, expensive, and adding only a small increase in efficiency, perhaps only half a percent. In 2006, the total market for digital power management ICs was about $6M.
The introduction of at least five digital management ICs in 2007 focused attention on the young market, and market analysts made predictions for its size to be anywhere from $800M to $1B by 2010. Steve Ohr, research director for Gartner Dataquest, came in at a more conservative $387M target for 2011. His prediction looks pretty smart right now, because the digital power market did not take off in the past year and doesn’t appear to be on course to hit $1B by 2010.
But Ohr isn’t trying to grab bragging rights. “The [digital power] market is starting essentially from nothing, and there are so many unknowns: What will the price of energy do, and how quickly will engineers accept and design in a radically new technology?” Ohr says. “It’s crystal ball gazing. I have no idea if its going to grow that fast – or faster.”
As an example of the uncertainties in the nascent market, his 2011 forecast included almost nothing for digital power control on the PC mother board, but he points to the apparent early success of CHiL Semiconductor, which has a state-machine-based digital controller with a serial bus control that targets just that market. Who knew?
So while the power supply market has not universally jumped on the digital power bandwagon, today’s skyrocketing power bills may accelerate digital power’s acceptance now, with even half a percent of power savings justifying the increased parts and engineering costs of digital power.
So, because of the turbulence in the digital power market, here is a list of digital power management ICs vendors — in alphabetical order:
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Analog Devices
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ChiL Semiconductor
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Linear Technology
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Marvell
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Maxim
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Primarion
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Silicon Laboratories
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Summit Micro
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Texas instruments
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Zilker Labs
Digital Power supplies
In addition to the general uncertainty about the rate of acceptance of digital power, the power supply world has the added uncertainty of a patent claim covering serial bus communication for dc-dc point-of-load (POL) converters. Power-One claims that the PMBus architecture, developed by an industry consortium of power supply manufacturers and power management IC vendors, is the same as Power-One’s patented “Z-One” architecture. The power supply industry could be taking a wait-and-see attitude about the outcome of the patent court case, or the relatively slow adoption of digital control for dc-dc POL converters could just be due to caution on the part of end customers, who will have to implement and justify a complex new subsystem communication system. So for this also-new market, the vendors are again ranked in alphabetical order.
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American Power Systems
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Artesyn (a division of Emerson Electric)
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Astec (a division of Emerson Electric)
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Cherokee International
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Coldwatt
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Ericsson
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Power-One
