LT1512 - SEPIC Constant-Current/Constant-Voltage Battery Charger

Features

  • Charger Input Voltage May Be Higher, Equal to or
  • Lower Than Battery Voltage
  • Charges Any Number of Cells Up to 30V*
  • 1% Voltage Accuracy for Rechargeable Lithium Batteries
  • 500kHz Switching Frequency Minimizes Inductor Size
  • 100mV Current Sense Voltage for High Efficiency
  • Battery Can Be Directly Grounded
  • Charging Current Easily Programmable or Shut Down
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LT1512 Typical Application
LT1512 Typical Application

Description

The LT®1512 is a 500kHz current mode switching regulator specially configured to create a constant-current/constantvoltage 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.

Maximum switch current on the LT1512 is 1.5A. This allows battery charging currents up to 1A 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.

Packaging

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
Drawing
RoHS
LT1512CGN#PBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LT1512CGN#TRPBF SSOP-16 GN C 05-08-1641 (GN16) Yes
LT1512CN8#PBF N-8 N C 05-08-1510 (N8) Yes
LT1512CS8#PBF SO-8 S8 C 05-08-1610 (S8) Yes
LT1512CS8#TRPBF SO-8 S8 C 05-08-1610 (S8) Yes
LT1512IGN#PBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LT1512IGN#TRPBF SSOP-16 GN I 05-08-1641 (GN16) Yes
LT1512IN8#PBF N-8 N I 05-08-1510 (N8) Yes
LT1512IS8#PBF SO-8 S8 I 05-08-1610 (S8) Yes
LT1512IS8#TRPBF SO-8 S8 I 05-08-1610 (S8) Yes


LT1512 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
(1-99)
Price
(1k)*
RoHS
LT1512CGN#PBF SSOP-16 C $5.25 $4.25 Yes
LT1512CGN#TRPBF SSOP-16 C $4.31 Yes
LT1512CN8#PBF N-8 C $4.50 $3.60 Yes
LT1512CS8#PBF SO-8 C $4.65 $3.75 Yes
LT1512CS8#TRPBF SO-8 C $3.81 Yes
LT1512IGN#PBF SSOP-16 I $5.90 $4.80 Yes
LT1512IGN#TRPBF SSOP-16 I $4.86 Yes
LT1512IN8#PBF N-8 I $5.15 $4.15 Yes
LT1512IS8#PBF SO-8 I $5.35 $4.25 Yes
LT1512IS8#TRPBF SO-8 I $4.31 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

Designed for Automotive and Transportation Applications

AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT1512IGN#PBF SSOP-16 I $5.90 $4.80 Yes
LT1512IGN#TRPBF SSOP-16 I $4.86 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.

Applications

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

*Maximum Input Voltage = 40V – VBAT

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Design Tools

LTspice

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:
LT1512

Technical Support