LT3791-1 - 60V 4-Switch Synchronous Buck-Boost Controller

Features

  • 4-Switch Single Inductor Architecture Allows VIN Above, Below or Equal to VOUT
  • Synchronous Switching: Up to 98.5% Efficiency
  • Wide VIN Range: 4.7V to 60V
  • 2% Output Voltage Accuracy: 1.2V ≤ VOUT < 60V
  • 6% Output Current Accuracy: 0V ≤ VOUT < 60V
  • Input and Output Current Regulation with Current Monitor Outputs
  • No Top FET Refresh in Buck or Boost
  • VOUT Disconnected from VIN During Shutdown
  • C/10 Charge Termination and Output Shorted Flags
  • Capable of 100W or greater per IC
  • 38-Lead TSSOP with Exposed Pad

Typical Application

LT3791-1 Typical Application
LT3791-1 Typical Application

Description

The LT®3791-1 is a synchronous 4-switch buck-boost voltage/ current regulator controller. The controller can regulate output voltage, output current, or input current with input voltages above, below, or equal to the output voltage. The constant-frequency, current mode architecture allows its frequency to be adjusted or synchronized from 200kHz to 700kHz. No top FET refresh switching cycle is needed in buck or boost operation. With 60V input, 60V output capability and seamless transitions between operating regions, the LT3791-1 is ideal for voltage regulator, battery/ super-capacitor charger applications in automotive, industrial, telecom, and even battery-powered systems.

The LT3791-1 provides input current monitor, output current monitor, and various status flags, such as C/10 charge termination and shorted output flag.

  Features
LT3791 OPEN LED Pin
LT3791-1 Replaces OPEN LED Pin With C/10 Pin Termination Flag

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

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

Part Number Package Code Temp Package
Drawing
RoHS
LT3791EFE-1#PBF TSSOP-38 FE E 05-08-1772 Yes
LT3791EFE-1#TRPBF TSSOP-38 FE E 05-08-1772 Yes
LT3791HFE-1#PBF TSSOP-38 FE H 05-08-1772 Yes
LT3791HFE-1#TRPBF TSSOP-38 FE H 05-08-1772 Yes
LT3791IFE-1#PBF TSSOP-38 FE I 05-08-1772 Yes
LT3791IFE-1#TRPBF TSSOP-38 FE I 05-08-1772 Yes
LT3791MPFE-1#PBF TSSOP-38 FE MP 05-08-1772 Yes
LT3791MPFE-1#TRPBF TSSOP-38 FE MP 05-08-1772 Yes


LT3791-1 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3791EFE-1#PBF TSSOP-38 E $6.79 $4.75 Yes
LT3791EFE-1#TRPBF TSSOP-38 E $4.81 Yes
LT3791HFE-1#PBF TSSOP-38 H $7.86 $5.50 Yes
LT3791HFE-1#TRPBF TSSOP-38 H $5.56 Yes
LT3791IFE-1#PBF TSSOP-38 I $7.50 $5.25 Yes
LT3791IFE-1#TRPBF TSSOP-38 I $5.31 Yes
LT3791MPFE-1#PBF TSSOP-38 MP $21.07 $14.75 Yes
LT3791MPFE-1#TRPBF TSSOP-38 MP $14.81 Yes
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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.

Click here to view our complete list of demo boards

Applications

  • Automotive, Telecom, Industrial Systems
  • High Power Battery-Powered System

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Design Tools

LTspice

LTspice® software 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

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
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice 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:
LT3791
LT3791-1

LTpowerCAD

The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD

Design tools for the following parts are available in LTpowerCAD:
LT3791-1

Technical Support