The RT9247 is a multi-phase buck DC/DC controllerintegrated with all control functions for GHz CPU VRM.The RT9247 controls 2 or 3 buck switching stages operatingin interleaved phase set automatically. The multi-phasearchitecture provides high output current while maintaininglow power dissipation on power devices and low stress oninput and output capacitors. The high equivalent operatingfrequency also reduces the component dimension and theoutput voltage ripple in load transient.RT9247 controls both voltage and current loops to achievegood regulation, response & power stage thermal balance.Precise current loop using RDS(ON) as sense componentbuilds precise load line for strict VRM DC & transientspecification and also ensures thermal balance of differentpower stages. The settings of current sense, droop tuning,VCORE initial offset and over current protection areindependent to compensation circuit of voltage loop. Thefeature greatly facilitates the flexibility of CPU power supplydesign and tuning.The DAC output of RT9247 supports VRD10 by 6-bit VIDinput, precise initial value & smooth VCORE transient atVID jump. The IC monitors the VCORE voltage for PGOODand over-voltage protection. Soft-start, over-currentprotection and programmable under-voltage lockout are alsoprovided to assure the safety of microprocessor and powersystem.