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LT3798: Isolated No Opto-Coupler Flyback Controller with Active PFC Data Sheet12/12/2012PDF413K
Overview
Features and Benefits
- Isolated PFC Flyback with Minimum Number of External Components
- VIN and VOUT Limited Only by External Components
- Active Power Factor Correction
- Low Harmonic Distortion
- No Opto-Coupler Required
- Constant-Current and Constant-Voltage Regulation
- Accurate Regulated Voltage and Current (±5% Typical)
- Energy Star Compliant (<0.5W No Load Operation)
- Thermally Enhanced 16-lead MSOP Package
Product Details
The LT3798 is a constant-voltage/constant-current isolated flyback controller that combines active power factor correction (PFC) with no opto-coupler required for output voltage feedback into a single-stage converter. A LT3798 based design can achieve a power factor of greater than 0.97 by actively modulating the input current, allowing compliance with most Harmonic Current Emission requirements.
The LT3798 is well suited for a wide variety of off-line applications. The input range can be scaled up or down, depending mainly on the choice of external components. Efficiencies higher than 86% can be achieved with output power levels up to 100W. In addition, the LT3798 can easily be designed into high DC input applications.
Applications
- Offline 5W to 100W+ Applications
- High DC VIN Isolated Applications
- Offline Bus Converter (12V, 24V or 48V Outputs)
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 (1)
Documentation & Resources
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R530 Reliability Data3/26/2018PDF20 K
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DC1817B - Demo Manual11/12/2014PDF399K
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No-Opto Isolated Flyback Converters7/13/2017PDF458K
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You Can Do Offline Power7/30/2012PDF839K
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LTspice: Evaluating Electrical Quantities1/31/2023
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LT3798 Video Product Brief10/15/2018
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Isolated Flyback Controller with PFC Controls Voltage or Current10/15/2018
Tools & Simulations
LTspice
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:
Product Recommendations
LT3798 Companion Parts
Recommended Related Parts
Design Resources
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.View our quality and reliability program and certifications for more information.
Part Number | Material Declaration | Reliability Data | Pin/Package Drawing | CAD Symbols, Footprints & 3D Models |
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LT3798EMSE#PBF | Material Declaration | Reliability Data | 16-Lead MSOP w/ EP | |
LT3798EMSE#TRPBF | Material Declaration | Reliability Data | 16-Lead MSOP w/ EP | |
LT3798HMSE#PBF | Material Declaration | Reliability Data | 16-Lead MSOP w/ EP | |
LT3798HMSE#TRPBF | Material Declaration | Reliability Data | 16-Lead MSOP w/ EP | |
LT3798IMSE#PBF | Material Declaration | Reliability Data | 16-Lead MSOP w/ EP | |
LT3798IMSE#TRPBF | Material Declaration | Reliability Data | 16-Lead MSOP w/ EP | |
LT3798MPMSE#PBF | Material Declaration | Reliability Data | 16-Lead MSOP w/ EP | |
LT3798MPMSE#TRPBF | Material Declaration | Reliability Data | 16-Lead MSOP w/ EP | |
Wafer Fabrication Data | R530 Reliability Data |
PCN-PDN Information
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Support & Discussions
LT3798 Discussions
Sample & Buy
Ordering FAQs
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Buy Now Pricing
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List Pricing
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Sampling
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Evaluation Boards
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.