VRM (voltage regulator module)
Beginner
A circuit right next to a chip. It turns the board’s voltage, its push of electricity, down to the weak push the chip runs on.
Novice
A DC-to-DC converter that steps a supply such as 12 V down to the chip’s core voltage, under 1 V, and holds it steady while the chip’s current jumps around. Big chips need hundreds of amps from it.
Expert
Usually a multiphase buck converter with a digital controller, placed as close as possible to the load (point of load). Efficiency, transient response (droop under load steps), phase count and the board area it takes are the main trade-offs.
Explained in Board and server (Systems).
See also: Point of load (PoL), Multiphase buck converter.