Digital power comes full circleWe've come a long way in the five or so years since the first manufacturer announced its so-called digital power supply— actually a standard linear supply with LED readout of voltage! Then 'digital' came to mean using, say, a 4- or 8-bit digital input to set the output voltage of the supply. Then the first systems to control tracking, sequencing, and output voltage of multiple devices arrived, largely software-based. Along about this time, we had spirited debates on the meaning of power management. Digital power's promoters took the lead, touting digital's edge in speed and accuracy over traditional analog circuitry. But that wasn't true. In the mix were the great DSP versus microcontroller wars in a rather contentious debate on how to best implement digital power in power management.
The purists of definition arrived to separate marketing hype from fact. They proclaimed that true power management (versus power conservation) implied proactive, dynamic control of a system, and if implemented by digital means, then using a digital feedback loop. In the meantime, the first generation of IC devices arrived to implement all the various philosophies as digital power attempted to be everything to all people.
It still is, but now in a different way. Now we're into second-generation parts, notes Jeff Shepard of the Darnell Group, perhaps the name most associated with bringing the big industry names together in a yearly forum to reconcile the topic. The new ICs are optimized (versus customized) for specific jobs. More companies are ready right now with products for all kinds of digital power management tasks. Gone are (most of) the debates over what constitutes digital power. It's coming together. Darnell's fourth Digital Power Forum, which will be held in September in San Francisco, will have about four times the number of participants as the first gathering. That's real progress.
Indeed, in any no-nonsense system that works, there's room for all. Too bad the world doesn't run the same way.