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  2. Power Management
  3. Supercapacitor Chargers
  4. LTC3351

Alternative Parts


Features and Benefits

  • Integrated Hot Swap Controller with Circuit Breaker
  • High Efficiency Synchronous Step-Down CC/CV Charging of One to Four Series Supercapacitors
  • Step-Up Mode in Backup Provides Greater Utilization of Stored Energy in Supercapacitors
  • 16-Bit ADC for Monitoring System Voltages/Currents, Capacitance and ESR
  • Programmable Undervoltage and Overvoltage Thresholds to 35V
  • VIN: 4.5V to 35V, VCAP(n): Up to 5V per Capacitor, Charge/Backup Current: >10A
  • Programmable Input Current Limit Prioritizes System Load Over Capacitor Charge Current
  • All N-FET Charger Controller and PowerPath Controller
  • Compact 44-Lead 4mm × 7mm QFN Package

Product Details

The LTC3351 is a backup power controller that charges and monitors a series stack of one to four supercapacitors. The LTC3351’s synchronous step-down controller drives N-channel MOSFETs for constant current/constant voltage charging with programmable input current limit. In addition, the step-down converter runs in reverse as a step-up converter to deliver power from the supercapacitor stack to the backup supply rail. Internal balancers eliminate the need for external balance resistors and each capacitor has a shunt regulator for overvoltage protection.

The LTC3351 monitors system voltages, currents, stack capacitance and ESR which can all be read over the I2C/SMBus port. The hot swap controller uses N-channel MOSFETs for inrush control and a low loss path from the input to the output. The ideal diode controller uses an N-channel MOSFET for a low loss power path from the supercapacitors to the output. The LTC3351 is available in a thermally enhanced low profile 44-lead 4mm × 7mm × 0.75mm QFN surface mount package.


  • Swappable PCIE Cards with NVM
  • High Current 12V Ride-Through UPS
  • Servers/Mass Storage/High Availability Systems

Product Lifecycle icon-recommended Recommended for New Designs

This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.

Evaluation Kits (2)

Tools & Simulations

Software and Simulation

Product Recommendations

LTC3351 Companion Parts

Recommended Related Parts

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
LTC3351EUFF#PBF Material Declaration Reliability Data 44-Lead DFN (4mm x 7mm w/ EP)
LTC3351EUFF#TRPBF Material Declaration Reliability Data 44-Lead DFN (4mm x 7mm w/ EP)
LTC3351IUFF#PBF Material Declaration Reliability Data 44-Lead DFN (4mm x 7mm w/ EP)
LTC3351IUFF#TRPBF Material Declaration Reliability Data 44-Lead DFN (4mm x 7mm w/ EP)
Wafer Fabrication Data

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Evaluation Boards

Pricing displayed is based on 1-piece.

Up to two boards can be purchased through Analog.com. To order more than two, please purchase through one of our listed distributors.

Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.