General Description
The RT9231A is a 4-in-one power controller optimized for high-performance microprocessor and computer applications. The IC integrates a PWM controller, triple linear controller as well as monitoring and protection functions into a 28-pin SOP package. The PWM controller regulates the microprocessor core voltage with a synchronous buck converter. The first linear controller supplies the computer system’s AGP 1.5V or 3.3V bus power. The second linear controller provides power for the 1.5V GTL bus and the 3rd linear controller provides 1.8V power for the North/South Bridge core voltage and/or cache memory circuits.

FEATUREs
• 4-in-one Regulated Voltages for Microprocessor Core, AGP Bus, North/South Bridge and/or Cache Memory, GTL Bus Power
• Compatible with HIP6021A
• Power-good Output Voltage Monitor

Switching section
• 5-bit DAC Programmable from 1.3V to 3.5V
• ±1% DAC Accuracy
• Fast Transient Response
• Full 0% to 100% Duty Cycle Driver
• Fixed 200kHz Switching Frequency
• Adaptive Non-overlapping Gate Driver
• Over-current Monitor Uses MOSFET RDS(ON)
• Over-voltage Protection Uses Lower MOSFET

Linear Section
• Fixed or User-adjustable Linear Regulator Output Voltage
• MOSFET and NPN Driving Capability
• Ultra Fast Response Speed
• Under-voltage Protection
• Internal Thermal Shutdown

APPLICATIONs
• Full Motherboard Power Regulation for Computer
• Low-voltage Distributed Power Supplies