The Achilles heel of all non-isolated voltage-regulator modules and point-of-load converters is the size and cost of the passives that store the energy needed when their loads require a big increase in current. Primarion tackled this problem with a phase-control approach.
Under normal load conditions, an array of Primarion's PX3520 Power Stage Chips supplies the load with multiphase power in a conventional manner (see the figure). When current demand jumps, Primarion's PX3536 controller resequences the phases so multiple power stages operate in tandem instead of sequentially. (The figure shows four phases using a PX3536. There's also a six-phase PX3535 controller.) The controllers are programmed via a PC, using a GUI-based setup program.
The Primarion PowerCode PX3535 and PX3536 Digital Controllers and Primarion PowerCode PX3520 Power Stage are available now. Volume pricing for both controllers and power converters is under $2 each.