LT3799 - Offline Isolated Flyback LED Controller with Active PFC

Features

  • Isolated PFC LED Driver with Minimum Number of External Components
  • TRIAC Dimmable
  • VIN and VOUT Limited Only by External Components
  • Active Power Factor Correction (Typical PFC > 0.97)
  • Low Harmonic Content
  • No Opto-Coupler Required
  • Accurate Regulated LED Current (±5% Typical)
  • Open LED and Shorted LED Protection
  • Thermally Enhanced 16-lead MSOP Package

Typical Application

LT3799 Typical Application
LT3799 Typical Application

Description

The LT3799 is an isolated flyback controller with power factor correction specifically designed for driving LEDs. The controller operates using critical conduction mode allowing the use of a small transformer. Using a novel current sensing scheme, the controller is able to deliver a well regulated current to the secondary side without using an opto-coupler. A strong gate driver is included to drive an external high voltage MOSFET. Utilizing an onboard multiplier, the LT3799 typically achieves power factors of 0.97. The FAULT pin provides notification of open and short LED conditions.

The LT3799 uses a micropower hysteretic start-up to efficiently operate at offline input voltages, with a third winding to provide power to the part. An internal LDO provides a well regulated supply for the part’s internal circuitry and gate driver.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

MS-16

LT3799 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LT3799EMSE#PBF MSOP 16 E $3.22 $2.25 View
LT3799EMSE#TRPBF MSOP 16 E $2.31 View
LT3799EMSE-1#PBF MSOP 16 E $3.22 $2.25 View
LT3799EMSE-1#TRPBF MSOP 16 E $2.31 View
LT3799IMSE#PBF MSOP 16 I $3.70 $2.59 View
LT3799IMSE#TRPBF MSOP 16 I $2.65 View
LT3799IMSE-1#PBF MSOP 16 I $3.70 $2.59 View
LT3799IMSE-1#TRPBF MSOP 16 I $2.65 View
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1595A LT3799 Demo Board - Offline Isolated Flyback Controller with PFC - Universal Input, VOUT(NOM) = 20V, I LED = 1A $150.00
DC1744A LT3799EMSE Demo Board u 90V VIN 270V, VOUT= 1A at ~ 4V $150.00
DC1775A LT3799 Demo Board - Offline Isolated Flyback Controller with PFC - Universal Input, VOUT(NOM) = 28V, I LED = 0.5A $175.00
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Click here to view our complete list of demo boards

Applications

  • Offline 4W to 100W+ LED Applications
  • High DC VIN LED Applications

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Design Tools

LTspiceIV

LTspice IV is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice IV

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice IV
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice IV does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As". After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice IV:
LT3799
LT3799-1

Technical Support