DESCRIPTION

The LX1681/1682 are monolithic, pulsewidth modulator controller ICs. They are designed to implement a flexible, low cost buck (step-down) regulator supply with minimal external components.

The LX1681 is a non-synchronous controller; the LX1682 has a synchronous driver for higher efficiency.

KEY FEATURES

■ Fixed 200kHz Switching Frequency

■ Constant Frequency Voltage-Mode Control Requires NO External Compensation

■ Hiccup-Mode Over-Current Protection

■ High Efficiency

■ Output Voltage Set By Resistor Divider

■ Under-Voltage Lockout

■ Soft-Start And Enable

■ Synchronous Rectification (LX1682)

■ Non-Synchronous Rectification (LX1681)

■ Small, 8-pin Surface Mount Package

APPLICATIONS

■ 5V to 3.3V Or Less Buck Regulators

■ FPGA Supplies

■ Microprocessor Chipset Supplies (e.g. Camino, Whitney, etc.)

■ Rambus® RIMMTM Supplies

■ Hard Disk Drives

■ Computer Add-on Cards