L4981

Active

L4981A: Fixed Frequency Average Current Mode; L4981B: Line Modulated Frequency Average Current Mode

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Product overview

Description

The L4981 I.C. provides the necessary features to achieve a very high power factor up to 0.99.

Realized in BCD 60II technology this power factor corrector (PFC) pre-regulator contains all the control functions for designing a high efficiency-mode power supply with sinusoidal line current consumption.

The L4981 can be easily used in systems with mains voltages between 85V to 265V without anyline switch. This new PFC offers the possibility to work at fixed frequency (L4981A) or modulated frequency (L4981B) optimizing the size of the input filter; both the operating frequency modes working with an average current mode PWM controller, maintaining sinusoidal line current without slope compensation.

Besides power MOSFET gate driver, precise voltage reference (externally available), error amplifier, under voltage lockout, current sense and the soft start are included. To limit the number of the external components, the device integrates protections as overvoltage and overcurrent. The overcurrent level can be programmed using simple resistor for L4981A. For a better precision and for L4981B an external divider must be used.

  • All features

    • PRECISE 2% ON CHIP REFERENCE EXTERNALLY AVAILABLE
    • OVERVOLTAGE, OVERCURRENT PROTECTION
    • SOFT START
    • LOW START-UP CURRENT (0.3mA TYP.)
    • HIGH CURRENT BIPOLAR AND DMOS TOTEM POLE OUTPUT
    • CONTROL BOOST PWM UP TO 0.99P.F.
    • UNIVERSAL INPUT MAINS
    • LIMIT LINE CURRENT DISTORTION TO < 5%
    • AVERAGE CURRENT MODE PWM FOR MINIMUM NOISE SENSITIVITY
    • UNDER VOLTAGE LOCKOUT WITH HYSTERESIS AND PROGRAMMABLE TURN ON THRESHOLD
    • FEED FORWARD LINE AND LOAD REGULATION

Circuit Diagram

The current status of a product:
Active: Product is in volume production
Evaluation: Product is under characterization. Limited Engineering samples available
Preview: Product is in design stage
Target: Product is in design feasibility stage.No commitment taken to produce
Proposal: Marketing proposal for customer feedback.No commitment taken to design or produce
NRND: Not Recommended for New Design.Product is in volume production only to support customers ongoing production.
Marketing description of the package type.Compliancy of the device with industry requirement domains (IRD)The RoHS status of a product:
ECOPACK 1: Initial grade to identify European RoHS compliant products.
ECOPACK 2: New grade to identify brominated chlorinated and antimony oxide flame retardant free products.
ECOPACK 3: Halogen free RoHS exemptions free products.
(*): ECOPACK 2 version available upon request.
(**): Some versions still existing in ECOPACK 1 or not compliant.
The current status of a product:
Active: Product is in volume production
Evaluation: Product is under characterization. Limited Engineering samples available
Preview: Product is in design stage
Target: Product is in design feasibility stage.No commitment taken to produce
Proposal: Marketing proposal for customer feedback.No commitment taken to design or produce
NRND: Not Recommended for New Design.Product is in volume production only to support customers ongoing production.
Budgetary PriceMarketing description of the package type.Storage method used to contain product.Main country of assembly or fabrication of the product.ECCNs are five character alpha-numeric designations used on the Commerce Control List to identify dual-use items for export control purposes. ECCNs are five character alpha-numeric designations used on the Commerce Control List to identify dual-use items for export control purposes.The value as specified by level (minTypMax) of the ambient temperature (in Cel) in which this item was designed to operate.The value as specified by level (minTypMax) of the ambient temperature (in Cel) in which this item was designed to operate.