DESCRIPTION

The LX1668 is a Monolithic Switching Regulator Controller IC designed to provide a low cost, high performance adjustable power supply for advanced microprocessors and other applications requiring a very fast transient response and a high degree of accuracy. It provides a programmable switching regulator output, together with one internal linear low dropout regulator and one adjustable linear regulator driver. The LX1668 offers a triple-output single-chip power supply for Pentium® II and other processors.

KEY FEATURES

■ 5-Bit Programmable Output For CPU Core Supply

■ Internal Fixed 2.5V Low Dropout Regulator

■ Adjustable Linear Regulator Driver

■ Complete Single-Chip Power Solution For Pentium II Processors

■ No Sense Resistor Required For Short-Circuit Current Limiting

■ Soft-Start And Hiccup-Mode Current Limiting Functions

■ Modulated Constant Off-Time Control Mechanism For Fast Transient Response And Simple System Design

■ Power Good Flag

■ Over-Voltage Pin & SCR

■ Digital-Compatible Inputs (Including VID Pins)

■ Output Disable Function Shuts Off PWM While Keeping 2.5V LDO Active - Compatible With Green PC And Instant On Requirements

■ Compatible to VRM8.2 - 8.4 Specifications

APPLICATIONS

■ Pentium II & Pentium III Processor Supplies

■ Voltage Regulator Modules

■ General Purpose And Microprocessor DC:DC Supplies