DESCRIPTION

· The LT1249 is an 8-pin power factor controller designed for universal offline power systems.

· It employs fixed high-frequency PWM current averaging, eliminating the need for slope compensation.

· The device minimizes line current distortion and uses a smaller magnetic element compared to peak current detection or zero current switching methods.

· It features a multiplier with a square gain function to maintain low line current distortion and high system stability at light loads.

· The LT1249 includes filtering capabilities to reject line switching noise and offers various protection features like peak current limiting and overvoltage protection.

· The internal switching frequency is set at 100kHz.

FEATURES

· High power factor over a wide load range with line current averaging.

· International operation without switches.

· Instantaneous overvoltage protection.

· Minimal line current dead zone.

· Typical 250 mA start-up supply current.

· Rejects line switching noise.

· Synchronization capability.

· Low quiescent current: 9mA.

· Fast 1.5A peak current gate driver.

APPLICATIONS

· Universal power factor corrected power supplies.

· Preregulators up to 1500W.