LT3479 - 3A, Full Featured DC/DC Converter with Soft-Start and Inrush Current Protection


  • Wide Input Voltage Range: 2.5V to 24V
  • 3A, 42V Internal Switch
  • High Efficiency Power Conversion: Up to 89%
  • Soft-Start
  • Frequency Set by External Resistor: 200kHz to 3.5MHz
  • Protection Against Input Short Circuits and Hot Plugging
  • Low VCESAT Switch: 0.3V at 2.5A (Typical)
  • Capable of Positive and Negative Outputs
  • Available in Thermally Enhanced 14-Lead (4mm × 3mm) DFN and 16-Lead TSSOP Packages

Typical Application

LT3479 Typical Application
LT3479 Typical Application


The LT3479 is a current mode, fixed frequency step-up DC/DC converter with an internal 3A, 42V switch. Efficiencies of up to 89% can be achieved in typical applications. It features a programmable soft-start function to limit inductor current during start-up and inrush current protection to protect the LT3479 during shorts and line transients. Both inputs of the error amplifier are available to the user allowing positive and negative output voltages. Through an external resistor, the user can program the switching frequency from 200kHz to 3.5MHz. The low profile (0.75mm) 14-pin, 4mm × 3mm DFN package provides excellent thermal performance in a small footprint. The LT3479 is also available in a thermally enhanced 16-pin TSSOP package.


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
LT3479EDE#PBF 4x3 DFN-14 DE E 05-08-1708 Yes
LT3479EDE#TRPBF 4x3 DFN-14 DE E 05-08-1708 Yes
LT3479EFE#PBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT3479EFE#TRPBF TSSOP-16 FE E 05-08-1663 (BC) Yes

LT3479 Package Drawing
LT3479 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
LT3479EDE#PBF 4x3 DFN-14 E $3.56 $3.00 Yes
LT3479EDE#TRPBF 4x3 DFN-14 E $3.12 Yes
LT3479EFE#PBF TSSOP-16 E $3.56 $3.00 Yes
LT3479EFE#TRPBF TSSOP-16 E $3.12 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
DC765B LT3479EDE Demo Board | Positive/ Negative Converter (LT3479 x2), Boost: 2.5V ≤ VIN ≤ 4.2V, Vout=7V@600mA, Inverter: 2.5V ≤ VIN ≤ 12V, Vout=-5V@600mA $175.00
DC843A LT3479EDE/ High Current Boost LED Driver, Vin = 2.7V-4.5V $100.00
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Click here to view our complete list of demo boards


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