LT1513 - SEPIC Constant- or Programmable-Current/Constant-Voltage Battery Charger


  • Charger Input Voltage May Be Higher, Equal to or Lower Than Battery Voltage
  • Charges Any Number of Cells Up to 20V
  • 1% Voltage Accuracy for Rechargeable Lithium Batteries
  • 100mV Current Sense Voltage for High Efficiency (LT1513)
  • 0mV Current Sense Voltage for Easy Current Programming (LT1513-2)
  • Battery Can Be Directly Grounded
  • 500kHz Switching Frequency Minimizes Inductor Size
  • Charging Current Easily Programmable or Shut Down

Typical Application

LT1513 Typical Application
LT1513 Typical Application


The LT1513 is a 500kHz current mode switching regulator specially configured to create a constant- or programmable-current/constant-voltage battery charger. In addition to the usual voltage feedback node, it has a current sense feedback circuit for accurately controlling output current of a flyback or SEPIC (Single-Ended Primary Inductance Converter) topology charger. These topologies allow the current sense circuit to be ground referred and completely separated from the battery itself, simplifying battery switching and system grounding problems. In addition, these topologies allow charging even when the input voltage is lower than the battery voltage. The LT1513 can also drive a CCFL Royer converter with high efficiency in floating or grounded mode.

Maximum switch current on the LT1513 is 3A. This allows battery charging currents up to 2A for a single lithium-ion cell. Accuracy of 1% in constant-voltage mode is perfect for lithium battery applications. Charging current can be easily programmed for all battery types.


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
LT1513-2CR#PBF DDPAK-7 R C 05-08-1462 Yes
LT1513-2CR#TRPBF DDPAK-7 R C 05-08-1462 Yes
LT1513-2CT7#PBF TO-220 T7 C 05-08-1422 (Std) Yes
LT1513-2IR#PBF DDPAK-7 R I 05-08-1462 Yes
LT1513-2IR#TRPBF DDPAK-7 R I 05-08-1462 Yes
LT1513-2IT7#PBF TO-220 T7 I 05-08-1422 (Std) Yes
LT1513CR#PBF DDPAK-7 R C 05-08-1462 Yes
LT1513CR#TRPBF DDPAK-7 R C 05-08-1462 Yes
LT1513IR#PBF DDPAK-7 R I 05-08-1462 Yes
LT1513IR#TRPBF DDPAK-7 R I 05-08-1462 Yes

LT1513 Package Drawing
LT1513 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
LT1513-2CR#PBF DDPAK-7 C $5.45 $4.40 Yes
LT1513-2CR#TRPBF DDPAK-7 C $4.52 Yes
LT1513-2CT7#PBF TO-220 C $5.15 $4.20 Yes
LT1513-2IR#PBF DDPAK-7 I $5.95 $4.80 Yes
LT1513-2IR#TRPBF DDPAK-7 I $4.92 Yes
LT1513-2IT7#PBF TO-220 I $5.65 $4.65 Yes
LT1513CR#PBF DDPAK-7 C $5.45 $4.40 Yes
LT1513CR#TRPBF DDPAK-7 C $4.52 Yes
LT1513IR#PBF DDPAK-7 I $5.95 $4.80 Yes
LT1513IR#TRPBF DDPAK-7 I $4.92 Yes
Buy NowRequest Samples
* 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


  • Charging of NiCd, NiMH, Lead-Acid or Lithium Rechargeable Cells
  • Precision Current Limited Power Supply
  • Constant-Voltage/Constant-Current Supply
  • Transducer Excitation
  • Universal Input CCFL Driver

Product Notifications

Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.

Forgot your password? Click here.
Need help? Email with questions and comments.

Design Tools


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:

Technical Support