LTC3331 - Nanopower Buck-Boost DC/DC with Energy Harvesting Battery Charger


  • Dual Input, Single Output DC/DCs with Input Prioritizer
    Energy Harvesting Input: 3.0V to 19V Buck DC/DC
    Battery Input: Up to 4.2V Buck-Boost DC/DC
  • 10mA Shunt Battery Charger with Programmable Float Voltages: 3.45V, 4.0V, 4.1V, 4.2V
  • Low Battery Disconnect
  • Ultra Low Quiescent Current: 950nA at no Load
  • Integrated Supercapacitor Balancer
  • Up to 50mA of Output Current
  • Programmable DC/DC Output Voltage, Buck UVLO, and Buck-Boost Peak Input Current
  • Integrated Low-Loss Full-Wave Bridge Rectifier
  • Input Protective Shunt: Up to 25mA at VIN ≥ 20V
  • 5mm × 5mm QFN-32 Package

Typical Application

LTC3331 Typical Application
LTC3331 Typical Application


The LTC®3331 integrates a high voltage energy harvesting power supply plus a buck-boost DC/DC powered from a rechargeable battery to create a single output supply for alternative energy applications. A 10mA shunt allows simple charging of the battery with harvested energy while a low battery disconnect function protects the battery from deep discharge. The energy harvesting power supply, consisting of an integrated full-wave bridge rectifier and a high voltage buck DC/DC, harvests energy from piezoelectric, solar, or magnetic sources. Either DC/DC converter can deliver energy to a single output. The buck operates when harvested energy is available, reducing the quiescent current draw on the battery to the 200nA required by the shunt charger, thereby extending the life of the battery. The buck-boost powers VOUT only when harvested energy is unavailable.

A supercapacitor balancer is also integrated, allowing for increased output storage. Voltage and current settings for both inputs and outputs are programmable via pin-strapped logic inputs. The LTC3331 is available in a 5mm × 5mm QFN-32 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
LTC3331EUH#PBF 5x5 QFN-32 UH E 05-08-1693 Yes
LTC3331EUH#TRPBF 5x5 QFN-32 UH E 05-08-1693 Yes
LTC3331IUH#PBF 5x5 QFN-32 UH I 05-08-1693 Yes
LTC3331IUH#TRPBF 5x5 QFN-32 UH I 05-08-1693 Yes

LTC3331 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
LTC3331EUH#PBF 5x5 QFN-32 E $5.07 $3.55 Yes
LTC3331EUH#TRPBF 5x5 QFN-32 E $3.61 Yes
LTC3331IUH#PBF 5x5 QFN-32 I $5.57 $3.90 Yes
LTC3331IUH#TRPBF 5x5 QFN-32 I $3.96 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.

Part Number Description Price Documentation
DC2151A LTC3331EUH Demo Board | Dual Input, Buck Energy Harvester with 10mA Shunt Charger Plus Buck-Boost for Li Ion System Power, 3V ≤ VIN ≤ 18V; Adj 1.8V ≤ Vout ≤ 5V $200.00
DC2321A Dust Energy Harvesting Demo Board with E-Ink Display, designed to connect to the DC2344A or DC2509A $150.00
Buy Now

Companion Boards

Part Number Description Price Documentation
DC2274A-A SmartMesh IP USB Network Manager, 100 mote capacity $125.00
DC2344A Gleanergy Multi-Source Energy Harvesting Demo Board with Battery Chargers and Life-Extenders for Use with DC2321A Dust Demo Board Contact Factory
DC2509A Gleanergy Multi-Source E H Demo Board with Battery Chargers and Life-Extenders for Use with DC2321A Dust Demo Board $175.00
DC2510A Shield Board for use with DC2321A Dust Demo Board $75.00
Buy Now
Click here to view our complete list of demo boards


  • Energy Harvesting
  • Solar Powered Systems with Battery Backup
  • Wireless HVAC Sensors and Security Devices
  • Mobile Asset Tracking

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

Models for the following parts are available in LTspice:

Technical Support