描述 Description

Key Features:
? INTERNAL START-UP CIRCUIT
? INTERNAL CURRENT SENSE BLANKING
? IMPROVED MICROPOWER START-UPCURRENT (300μA max.)
? CLAMPED E.A. OUTPUT FOR LOWERTURN-ON OVERSHOOT
? MULTIPLIER CLAMP LIMITS MAXIMUMINPUT CURRENT
? INTERNAL OVERVOLTAGE PROTECTIONREPLACES BUILT-IN C.S. OFFSET
? PWM OUTPUT CLAMP LIMITS MOSFETGATE DRIVE VOLTAGE
? INCREASED UVLO HYSTERESIS REDUCESSTART-UP TIMING (LX1562 only)
? LOW OPERATING CURRENT CONSUMPTION
? INTERNAL 1.5% REFERENCE
? TOTEM POLE OUTPUT STAGE
? AUTOMATIC CURRENT LIMITING OF BOOSTSTAGE
? DISCONTINUOUS MODE OF OPERATIONWITH NO CURRENT GAPS
? NO SLOPE COMPENSATION REQUIREDThe LX1562 is a second-generation family of power factor correction controllers using a discontinuous mode of operation. They are optimized for electronic ballast applications. Many improvements have been made over the original SG3561A controller introduced by Silicon General Semiconductor in 1992.New features include the addition of an internal start-up circuit eliminating bulky external components while allowing independent boost converter operation. Addition of internal current sense blanking eliminating the need for an external R/C filter network. Internal clamping of the error amplifier and multiplier outputs improves turn on overshoot characteristics and current limiting. Special circuitry has also been added to prevent no load runaway conditions. And finally, output drive clamps limiting power MOSFET gate drive independent of supply voltage greatly enhance the products practical application.Although the IC design has been optimized for electronic ballast applications, it can also be used for power factor correction in lower power (typ ??ROHS