Description

L6668 is a current-mode primary controller IC, designed to build single-ended converters.

The IC drives the system at fixed frequency at heavy load and an improved Standby function causes a smooth frequency reduction as the load is progressively reduced. At very light load the device enters a special operating mode (burst-mode with fixed, externally programmed peak current) that, in addition to the on-board high-voltage start-up and the very low quiescent current, helps keep low the consumption from the mains and be compliant with energy saving regulations. To allow meeting compliance with these standards in power-factor-corrected systems too, an interface with the PFC controller is provided that enables to turn off the pre-regulator when the load level falls below a threshold.

General Features

■ MULTIPOWER BCD TECHNOLOGY

■ LOAD-DEPENDENT CURRENT-MODE CONTROL: FIXED-FREQUENCY (HEAVY LOAD), FREQUENCY FOLDBACK (LIGHT LOAD), BURST-MODE (NO-LOAD)

■ ON-BOARD HIGH-VOLTAGE START-UP

■ IMPROVED STANDBY FUNCTION

■ LOW QUIESCENT CURRENT (< 2 mA)

■ SLOPE COMPENSATION

■ PULSE-BY-PULSE & HICCUP-MODE OCP

■ INTERFACE WITH PFC CONTROLLER

■ DISABLE FUNCTION (ON/OFF CONTROL)

■ LATCHED DISABLE FOR OVP/OTP FUNCTION

■ PROGRAMMABLE SOFT-START

■ 2% PRECISION REFERENCE VOLTAGE EXTERNALLY AVAILABLE

■ ±800 mA TOTEM POLE GATE DRIVER WITH INTERNAL CLAMP AND UVLO PULL-DOWN

■ BLUE ANGEL, ENERGY STAR, EU CODE OF CONDUCT COMPLIANT

■ SO16 PACKAGE ECOPACK®

APPLICATIONS

■ HI-END AC-DC ADAPTERS/CHARGERS FOR NOTEBOOKS.

■ LCD/CRT MONITORS, LCD/CRT TV

■ DIGITAL CONSUMER