Automotive Low Voltage SEPIC Stage Converts 4V…40Vin to 12Vout@2.5A Reference Design
This product has been released to the market and is available for purchase. For some products, newer alternatives may be available.

Description & Features

Technical documentation

Support & Training

Order Now

See the Important Notice and Disclaimer covering reference designs and other TI resources.


This small SEPIC converter accepts a wide input voltage range, 4V...40V, from automotive battery and supports the cranking phase. Vout is kept stable thank to the SEPIC topology. During cranking the input voltage can reach vaules as low as 4V. Extensive testing with a source generator have been performed.

  • Supports the highly demanding cranking profile by stable 12Vout@2.5A
  • Good efficiency from 9V to 24Vin in the range of 88%...91%
  • Low noise generation thank to a mix of electrolytic capacitor, ferrite bead, and ceramic filter

See the Important Notice and Disclaimer covering reference designs and other TI resources.


Schematic/Block Diagram

Quickly understand overall system functionality.

Download Schematic

Test Data

Get results faster with test and simulation data that's been verified.

Download Test Data

Design Files

Download ready-to-use system files to speed your design process. Get Viewer.

Download Design Files

(Output Voltage 1)
Vin (Min) (V)4
Vin (Max) (V)40
Vout (Nom) (V)12
Iout (Max) (A)2.5
Output Power (W)30
Input TypeDC
TopologySepic- CCM

TI Devices (1)

Order samples, get tools and find more information on the TI products in this reference design.

Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
LM3481  2.97V to 48V High-Efficiency Controller for Boost, SEPIC and Flyback  Step-up (boost) regulators  Sample & Buy View Design Kits & Evaluation Modules

CAD/CAE symbols

Part # Package | Pins CAD File (.bxl) STEP Model (.stp)
LM3481 Download Download

Texas Instruments and Accelerated Designs, Inc. have collaborated together to provide TI customers with schematic symbols and PCB layout footprints for TI products.

Step 1: Download and install the free download.

Step 2: Download the Symbol and Footprint from the CAD.bxl file table.

Technical documentation

See the Important Notice and Disclaimer covering reference designs and other TI resources.

User guide (1)
Title Type Size (KB) Date
PDF 812 10 Apr 2015
Design files (6)
Title Type Size (KB) Date
ZIP 187 10 Apr 2015
ZIP 324 10 Apr 2015
ZIP 78 10 Apr 2015
PDF 71 10 Apr 2015
PDF 106 10 Apr 2015
PDF 155 10 Apr 2015

Support & training

TI E2E™ forums with technical support from TI engineers

Search our extensive online knowledge base where millions of technical questions and answers are available 24/7.

Search answers from TI experts

Content is provided 'AS IS' by the respective TI and Community contributors and does not constitute TI specifications.
See terms of use.

If you have questions about quality, packaging, or ordering TI products visit our Support page.

Technical articles