DESIGN VIEW is the summary of the complete DESIGN SOLUTION contributed article, which begins on Page 2.
Rapidly evolving processors consistently challenge power-supply designers to solve complex power-delivery issues for desktops, workstations, and servers. In fact, powering the microprocessor presents the most difficult power solution in the whole computer system.
Faster transients and improved operation over temperature are just a few of the new design requirements. But the most difficult design challenge stems from the fact that the processor's specified operating-voltage tolerance keeps getting tighter and tighter. It's a bit like playing a video game in which each successive level becomes increasingly difficult. To be successful, you must first understand the rules—in this case, the processor's requirements.
But understanding these "rules of the game" means more than just memorizing the "numbers." You need to understand the requirements and potential options so that you can make better tradeoffs and decisions in your designs and products. Plus, you'll have an edge if you exploit the tricks and techniques that are available.
This article explores some of those tricks of the trade to better power delivery. For example, to simplify specifications and better define processor power requirements, Intel uses a "load-line" approach. Load line is basically an operating voltage window. If the voltage stays within the window, the power supply meets the processor specification. Another approach is a "droop" system, where the voltage decreases at a defined rate as the operating current increases.
Discussed in depth is the dynamic voltage identification (VID) spec, or VID "on-the-fly." VID allows the processor to save power by lowering its VCORE voltage while running. A voltage-regulation-module (VRM) control-chip design example is included.
Full article begins on Page 2