Offline Isolated Flyback LED Controller with Active PFC
Features and Benefits
- Isolated PFC LED Driver with Minimum Number of External Components
- 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
The LT3799-1 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 LT3799-1 typically achieves power factors of 0.97. The FAULT pin provides notification of open and short LED conditions. The LT3799-1 offers improved line regulation over the LT3799, but is not designed for use with a TRIAC dimmer.
The LT3799-1 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.
|Triac Dimmable||LED Current Regulator|
- Offline 4W to 100W+ LED Applications
- High DC VIN LED Applications
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (2)
Demonstration circuit 1816B is an off-line isolated flyback LED driver featuring LT3799-1. The demo board provides a single constant current output of 3A over an LED string voltage from 22V to 38V. It is optimized to operate over a wide AC input voltage range (90VAC to 305VAC, 47Hz to 63Hz). LED current typically stays within ±5% over the whole input voltage range. It provides a high power factor (>0.9) enabling a single design to be used worldwide. It is also designed to comply with the IEC 61000-3-2 Class C harmonics standard and the EN55015B conducted EMI standard.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
To launch ready-to-run LTspice demonstration circuits for this part:
Step 1: Download and install LTspice on your computer.
Step 2: Click on the link in the section below to download a demonstration circuit.
Step 3: If LTspice does not automatically open after clicking the link below, 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.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
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 Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.