[RichTek]

General Description
The RT9230 is a 4-in-one power controller optimized for high-performance microprocessor and computer applications. The IC integrates two PWM controller, two linear controllers as well as monitoring and protection functions into a 28-pin SOP package. The first PWM controller regulates the microprocessor core voltage with a synchronous buck converter, while the second PWM controller supplies the computer system’s AGP 1.5V or 3.3V bus power with a standard buck converter. The first linear regulator provides power for the 1.5V GTL bus and the second linear regulator provides 1.8V power for the North/South Bridge core voltage and/or cache memory circuits.
The RT9230 features an Intel-compatible, TTL 5-bit programmable DAC that adjusts the core voltage from 2.1V to 3.5V in 0.1V increments and from 1.3V to 2.05V in 0.05V steps. The 5-bit DAC has a typical ±1% tolerance. The second PWM controller is user selectable for output level of 1.5V and 3.3V with ±2.5% accuracy. The linear controllers drives external N-MOSFET or NPN bipolar for the pass transistor to provide fixed output voltages of 1.5V ±3% and 1.8V ±3%.
The RT9230 monitors all the output voltages. A Power -good signal is issued when the core voltage is within ±10% of the DAC setting and the other levels are above their under-voltage levels. Additional build-in over-voltage protection for the core output uses the lower MOSFET to prevent output voltage above 115% of the DAC setting. The PWM over-current function monitors the output current using the voltage drop across the MOSFET’s RDS(ON), which eliminates the need for a current sensing resistor.

FEATUREs
● 4-in-one Regulated Voltages for Microprocessor
   Core, AGP Bus, North/South Bridge and/or
   Cache Memory, GTL Bus Power
● Compatible with HIP6020
● 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 Linear Regulator Output Voltage
● MOSFET or 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