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.


For complete and up to date package information and drawings, please refer to our packaging page


LTC3331 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Pins Temp Price (1-99) Price (1k)* RoHS Data
LTC3331EUH#PBF QFN 32 E $5.07 $3.55 View
LTC3331EUH#TRPBF QFN 32 E $3.61 View
LTC3331IUH#PBF QFN 32 I $5.57 $3.90 View
LTC3331IUH#TRPBF QFN 32 I $3.96 View
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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
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
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  • Energy Harvesting
  • Solar Powered Systems with Battery Backup
  • Wireless HVAC Sensors and Security Devices
  • Mobile Asset Tracking

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