LT3791 - 60V 4-Switch Synchronous Buck-Boost LED Driver Controller


  • 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
  • Wide VOUT Range: 0V to 60V (52V LED)
  • ±6% LED Current Accuracy: 0V ≤ VLED < 52V
  • True Color PWM™ and Analog Dimming
  • LED and Input Current Regulation with Current Monitor Outputs
  • No Top MOSFET Refresh in Buck or Boost
  • VOUT Disconnected From VIN During Shutdown
  • Open or Shorted LED Fault Protection
  • Capable of 100W or Greater per IC
  • 38-Lead TSSOP with Exposed Pad

Typical Application

LT3791 Typical Application
LT3791 Typical Application


The LT®3791 is a synchronous 4-switch buck-boost LED driver controller. The controller can regulate LED current up to 52V of LED string with input voltages above, below, or equal to the output voltage. The constant-frequency, forced-continuous current mode architecture allows its frequency to be adjusted or synchronized from 200kHz to 700kHz. No top MOSFET refresh switching cycle is needed in buck or boost operation. With 60V input, 60V output capability and seamless transitions between operating regions, the LT3791 is ideal for LED driver applications in automotive, industrial, and even battery-powered systems.

For new designs we recommend the LT8391: 60V synchronous 4-switch, buck-boost LED controller due to its numerous performance improvements over the LT3791.

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


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
LT3791EFE#PBF TSSOP-38 FE E 05-08-1772 Yes
LT3791EFE#TRPBF TSSOP-38 FE E 05-08-1772 Yes
LT3791HFE#PBF TSSOP-38 FE H 05-08-1772 Yes
LT3791HFE#TRPBF TSSOP-38 FE H 05-08-1772 Yes
LT3791IFE#PBF TSSOP-38 FE I 05-08-1772 Yes
LT3791IFE#TRPBF TSSOP-38 FE I 05-08-1772 Yes
LT3791MPFE#PBF TSSOP-38 FE MP 05-08-1772 Yes
LT3791MPFE#TRPBF TSSOP-38 FE MP 05-08-1772 Yes

LT3791 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
LT3791EFE#PBF TSSOP-38 E $6.79 $4.75 Yes
LT3791EFE#TRPBF TSSOP-38 E $4.81 Yes
LT3791HFE#PBF TSSOP-38 H $7.86 $5.50 Yes
LT3791HFE#TRPBF TSSOP-38 H $5.56 Yes
LT3791IFE#PBF TSSOP-38 I $7.50 $5.25 Yes
LT3791IFE#TRPBF TSSOP-38 I $5.31 Yes
LT3791MPFE#PBF TSSOP-38 MP $21.07 $14.75 Yes
LT3791MPFE#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.

Part Number Description Price Documentation
DC1666A LT3791 Demo Board | 4.7V-60V Input Drives 25V of LEDs at 2A (scalable to 100W) $200.00
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Click here to view our complete list of demo boards


  • Automotive Head Lamps/Running Lamps
  • General Purpose Lighting

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