The NCP5393B is a multiphase synchronous buck regulator controller designed to power the Core and Northbridge of an AMD microprocessor. The controller has a user configurable two, three, or four phase regulator for the Core and an independent single phase regulator to power the microprocessor Northbridge. The NCP5393B incorporates differential voltage sensing, differential phase current sensing, optional load-line voltage positioning, and programmable VDD and VDDNB offsets to provide accurately regulated power parallel- and serial-VID AMD processors. Dual-edge multiphase modulation provides the fastest initial response to dynamic load events. This reduces system cost by requiring less bulk and ceramic output capacitance to meet transient regulation specifications. High performance operational error amplifiers are provided to simplify compensation of the VDD and VDDNB regulators. Dynamic Reference Injection further simplifies loop compensation by eliminating the need to compromise between response to load transients and response to VID code changes. Features