RT9241B

The RT9241A/B is a two-phase buck DC/DC controller integrated with all control functions for high performance processor VRM. The RT9241A/B drives 2 buck switching stages operating in 180 degree phase shift. The twophase architecture provides high output current while maintaining low power dissipation on power devices and low stress on input and output capacitors. The high equivalent operating frequency also reduces the component dimension and the output voltage ripple in load transient.

RT9241A/B regulates both easily set voltage and current loops. Precise current sharing for power stage is achieved by differential input current sense and processing circuit. The settings of current sense, droop tuning and over current protection are independent to compensation circuit of voltage loop. The feature greatly facilitates the flexibility of CPU power supply design and tuning.

The RT9241A/B uses a 5-bit DAC of 1.1V to 1.85V (25mV/step) output with load current droop compensation to meet the strict VRM transient requirement. The IC monitors the VCORE voltage for PGOOD and over voltage protection. Soft start, over current protection and programmable under voltage lockout are also provided to assure the safety of microprocessor and power system.