Fault tolerant voltage regulator module circuit for supplying core voltage and cache voltage to a processor

Abstract

A fault tolerant voltage regulator module (VRM) circuit for a processor simultaneously supplies a core voltage to a plurality of processors, has a plurality of main VRMs (VRM) for supplying the same core voltage to the plurality of processors, a stand-by VRM for use upon a fault occurring in the plurality of main VRMs, a plurality of diodes connected in parallel between each of the main VRMs and the stand-by VRM for automatically supplying power to the stand-by VRM, a plurality of first power islands for connecting each of the plurality of main VRMs to the processor and each of output port of the plurality of diodes, a control signal set switch for setting output voltage level of the stand-by VRM and a second power island for connecting the stand-by VRM to input ports of the plurality of diodes and the control signal set switch. When a processor core voltage level and L2 cache voltage level are different, a fault tolerant VRM circuit further has a plurality of schottky diodes and a plurality of power MOSFETs for by-passing the schottky diodes so that the stand-by VRM can support two different voltage levels. The circuit improves stability of supplying board power owing to a fault tolerant VRM in processors and enables just one stand-by VRM to effect simultaneous support of a plurality of main VRMs and even different voltage level main VRMs using schottky diodes.