RT9246A Datasheet | Richtek

Description The RT9246A is a multi-phase buck DC/DC controller integrated with all control functions for GHz CPU VRM. The RT9246A controls 2 or 3 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. RT9246A controls both voltage and current loops to achieve good regulation, response & power stage thermal balance. Precise current loop using Inductor DCR as sense ponent builds precise load line for strict VRM DC & transient specification and also ensures thermal balance of different power stages. The settings of current sense, droop tuning, VCORE initial offset and over current protection are independent to pensation circuit of voltage loop. The feature greatly facilitates the flexibility of CPU power supply design and tuning. The DAC output of RT9246A supports K8 CPU by 5-bit VID input, precise initial 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. Features z z z z z z z z Multi-Phase Power Conversion with Automatic Phase Selection K8 DAC Output with Active Droop pensation for Fast Load Transient Smooth VCORE Transition at VID Jump Power Stage Thermal Balance by Inductor 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 Ro HS pliant and 100% Lead (Pb)-Free Applications AMD® Athlon TM 64 and Opteron TM Processors Voltage Regulator z Low Output Voltage, High Current DC-DC Converters z Voltage Regulator...