Digital Diet Slims Your Power Designs

Jul 31, 2007 3:47 PM
By Lou Pechi, President, STRATA-Strategic Advisors, San Diego, Calif.

Because this reduction in density occurred slowly, its effects were not initially noticeable. But eventually, the impact became apparent. This situation might be likened to a person who does not pay attention to what they eat and gradually adds inches to their waistline. The time for applying a “digital diet” to slim power-supply designs has arrived.

Such a diet consists of converting the fat analog signals to slim digital bits that can be easily digested by the predominant CMOS circuitry, and incorporate all the control, monitoring and management functions into slim silicon. A digital diet also will reduce and slim down the fat inductors and bulky capacitors needed in supplies using pure analog power conversion.

The arguments against converting to full digital power conversion echo the arguments against going on a food diet. One of the most common arguments is that we need to develop a common, uniform and proven digital power standard for all participants to follow. This would be nice, but as we wait for common agreement on the right diet to follow, our designs are getting fatter and fatter. We cannot wait any longer; the digital diet needs to be implemented today.

Some argue that digital conversion is too costly and that most of the functions can be achieved as well by using cheaper analog circuitry. Others indicate that digital conversion and control is too complicated to implement in power supplies. Other arguments against going on a digital diet range from the reluctance to use an unproven concept to the feeling that digital conversion and management is ineffective. There is also the basic denial of the need for digital control. Others simply take a wait-and-see attitude until it becomes an accepted technology by all.

Just as a regular diet offers the added benefits of better health, mobility and personal well being, a digital diet offers many secondary benefits beyond pc-board reduction and increased power density. For example, the number of components in a typical point-of-load distributed-power design can be reduced by a factor of 20, with the associated increase in system reliability. The number of pc-board traces, development time and the total system cost can be reduced as well.

Given all these advantages, don’t the arguments against going digital, sound more and more like the misgivings of an individual who continually puts off a needed diet, saying, “I’ll start it later”?

So power-supply designers, stop the excuses. Get your power designs in shape by putting them on a digital diet. When you take this step, you’ll produce products that are slimmer and smarter, and you’ll create them faster in the future.

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© 2007 Penton Media, Inc.