Intel Corporation
STACKED BUCK CONVERTER WITH INDUCTOR SWITCHING NODE PRE-CHARGE AND CONDUCTION MODULATION CONTROL

Abstract:

A stacked voltage regulator (VR) that pre-charges inductor switching node to mitigate EOS. The stacked VR comprises at least three n-type devices (low-side) and three p-type devices (high-side) coupled in series. The three p-type stacked devices are part of a high-side of the VR. Node Vx coupling one of the n-type devices and one of the p-type devices is coupled to an inductor, which is also coupled to a load capacitor. During the inductor charging phase, in the low-to-high transition, a small p-type device is added to pre-charge the inductor switching node (V.sub.x) from "0" to "VDD-Vth" through the low-side by connecting a generated mid-rail "Vdd" to the internal node of the n-type stack for a short period (e.g., about 50 ps). A controlled conductance modulation (CCM) scheme on the high-side top switch during the inductor charging phase is used to mitigate the ringing without controlling the gate drive strength.