RT9245B Datasheet | Richtek

Description RT9245B is a multi-phase buck DC/DC controller integrated with all control functions for AMD K8 CPU. The RT9245B could be operated with 2, 3 or 4 buck switching stages operating in interleaved phase set automatically. The multiphase 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 ponent dimension and the output voltage ripple in load transient. RT9245B implements both voltage and current loops to achieve good regulation, response and power stage thermal balance. RT9245B applies the DCR sensing technology newly. The RT9245B extracts the ESR of output inductor as sense ponent to deliver a precise load line regulation and good thermal balance for next generation processor application. Current sense setting, droop tuning, VCORE initial offset and ov er current protection are independent on pensation circuit of voltage loop. The feature greatly facilitates the flexibility of CPU power supply design and tuning. The DAC output of RT9245B supports AMD K8 6-bit VID, precise offset value & smooth VCORE transient at VID jump. 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. The RT9245B es to a small footprint package TSSOP-28. Features l l l l l l l l l Multi-Phase Power Conversion with Automatic Phase Selection 6-bit AMD K8 M2 DAC Output with Active Droop pensation for Fast Load Transient Smooth VCORE Transition at VID Jump Power Stage Thermal Balance by DCR Current Sense Hiccup Mode Over-Current Protection Programmable Switching Frequency (50k Hz to 400k Hz per Phase), Under-Voltage Lockout and Soft Start High Ripple Frequency Times Channel Number 28-TSSOP Package Ro HS pliant and 100% Lead (Pb)-Free Applications l l l AMD K8...