RT9237

The RT9237 is a multi-phase buck DC/DC controllerintegrated with all control functions for highperformance processor VRM. The RT9237 drives 2,3 or 4 buck switching stages operating in interleavedphase set automatically. The multi-phasearchitecture provides high output current whilemaintaining low power dissipation on power devicesand low stress on input and output capacitors. Thehigh equivalent operating frequency also reducesthe component dimension and the output voltageripple in load transient.

RT9237 regulates both easily set voltage andcurrent loops. Precise current sharing for powerstage is achieved by differential input current senseand processing circuit. The settings of currentsense, droop tuning and over current protection areindependent to compensation circuit of voltage loop.

The feature greatly facilitates the flexibility of CPUpower supply design and tuning.The RT9237 uses a 5-bit DAC of 1.1V to 1.85V(25mV/step) output with load current droopcompensation to meet the strict VRM transientrequirement. The IC monitors the VCORE voltagefor PGOOD and over voltage protection. Soft start,over current protection and programmable undervoltage lockout are also provided to assure thesafety of microprocessor and power system.