LT3798 - Isolated No Opto-Coupler Flyback Controller with Active PFC

Features

  • 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

Typical Application

LT3798 Typical Application
LT3798 Typical Application

Description

The LT®3798 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.

Packaging

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

MS-16

LT3798 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LT3798EMSE#PBF MSOP 16 E $3.22 $2.25 View
LT3798EMSE#TRPBF MSOP 16 E $2.31 View
LT3798HMSE#PBF MSOP 16 H $4.11 $2.88 View
LT3798HMSE#TRPBF MSOP 16 H $2.94 View
LT3798IMSE#PBF MSOP 16 I $3.70 $2.59 View
LT3798IMSE#TRPBF MSOP 16 I $2.65 View
LT3798MPMSE#PBF MSOP 16 MP $9.99 $6.99 View
LT3798MPMSE#TRPBF MSOP 16 MP $7.05 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
DC1817B LT3798EMSE Isolated Demo Board VIN = 90VAC to 265VAC, VOUT = 24V @ 2A High Voltage $200.00
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Click here to view our complete list of demo boards

Applications

  • Offline 5W to 100W+ Applications
  • High DC VIN Isolated Applications
  • Offline Bus Converter (12V, 24V or 48V Outputs)

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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:
LT3798

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