LT3491 - White LED Driver in SC70 with Integrated Schottky


  • Drives Up to Six White LEDs from a 3V Supply
  • High Side Sense Allows “One Wire Current Source”
  • Internal Schottky Diode
  • One Pin Dimming and Shutdown
  • 27V Open LED Protection
  • 2.3MHz Switching Frequency
  • ±5% Reference Accuracy
  • VIN Range: 2.5V to 12V
  • Requires Only 1µF Output Capacitor
  • Wide 300:1 True Color PWMTM Dimming Range
  • 8-Lead SC70 Package
  • Low Profile 6-Lead DFN Package (2mm × 2mm × 0.75mm)

Typical Application

LT3491 Typical Application
LT3491 Typical Application


The LT3491 is a fixed frequency step-up DC/DC converter specifically designed to drive up to six white LEDs in series from a Li-Ion cell. Series connection of the LEDs provides identical LED currents resulting in uniform brightness and eliminating the need for ballast resistors. The device features a unique high side LED current sense that enables the part to function as a “one wire current source;” one side of the LED string can be returned to ground anywhere, allowing a simpler one wire LED connection. Traditional LED drivers use a grounded resistor to sense LED current, requiring a 2-wire connection to the LED string.

The 2.3MHz switching frequency allows the use of tiny inductors and capacitors. A single pin performs both shutdown and accurate LED dimming control. Few external components are needed: open-LED protection and the Schottky diode are all contained inside the tiny SC70 package. With such a high level of integration, the LT3491 provides a high efficiency LED driver solution in the smallest of spaces.


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
LT3491EDC#PBF 2x2 DFN-6 DC6 E 05-08-1703 Yes
LT3491EDC#TRMPBF 2x2 DFN-6 DC6 E 05-08-1703 Yes
LT3491EDC#TRPBF 2x2 DFN-6 DC6 E 05-08-1703 Yes
LT3491ESC8#PBF SC-70 SC8 E 05-08-1639 Yes
LT3491ESC8#TRMPBF SC-70 SC8 E 05-08-1639 Yes
LT3491ESC8#TRPBF SC-70 SC8 E 05-08-1639 Yes

LT3491 Package Drawing
LT3491 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
LT3491EDC#PBF 2x2 DFN-6 E $1.79 Yes
LT3491EDC#TRMPBF 2x2 DFN-6 E $1.79 $1.35 Yes
LT3491EDC#TRPBF 2x2 DFN-6 E $1.79 $1.30 Yes
LT3491ESC8#PBF SC-70 E $1.86 Yes
LT3491ESC8#TRMPBF SC-70 E $1.86 $1.32 Yes
LT3491ESC8#TRPBF SC-70 E $1.86 $1.30 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
DC905A LT3491ESC8 Demo Board $75.00
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Click here to view our complete list of demo boards


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