Digital Power Q&A

Question:
"Is the power design community ready to switch from analog PWM controllers to digital PWM controllers?"

Answers:

Bob White Staff EngineerArtesyn Technologies

"There are two reasons to use digital instead of analog in a given application: it costs less or can do something valuable that cannot be done in analog. Cost is an open question. However, there are some clear opportunities to add value in digital PWM that are difficult or impossible in analog. One possibility is tuning control loops to their loads by GUI rather than by soldering iron.

Another is adaptive control loops that adjust their compensation ’on the fly’ to maintain optimum performance over dynamically changing conditions. As soon as the IC suppliers offer such devices with only a 10% to 20% price penalty, power designers will start making the switch. However, I do expect digital and analog PWM to co-exist for many, many years."

"To answer this question perhaps it is better to ask 'Are power designers prepared to stay with analog-based solutions?' Given the ever increasing demands for performance and features placed on power systems today, analog based solutions require complex, expensive and costly support circuitry to enable those features. With analog solutions there is a need for PLLs for synchronization and interleave, ADCs and a MUX for monitoring, sensing and feedback circuits for current share, a DAC for output voltage set point and margining, etc. - and all this is fixed circuitry on the board.

With a digital solution these features and many more are completely integrated into the silicon resulting in a lower cost, lower complexity, lower risk and more feature-enabled system all configurable via a standard interface. Only those who enjoy the fine art of tedious debug and engineering redesign will stay with analog-based solutions in the future."