LTC3350 - High Current Supercapacitor Backup Controller and System Monitor


  • 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
  • 14-Bit ADC for Monitoring System Voltages/Currents, Capacitance and ESR
  • Active Overvoltage Protection Shunts
  • Internal Active Balancers—No Balance Resistors
  • VIN: 4.5V to 35V, VCAP(n): Up to 5V per Capacitor, Charge/Backup Current: 10+A
  • Programmable Input Current Limit Prioritizes System Load Over Capacitor Charge Current
  • Dual Ideal Diode PowerPath™ Controller
  • All N-FET Charger Controller and PowerPath Controller
  • Compact 38-Lead 5mm × 7mm QFN Package

Typical Application

LTC3350 Typical Application
LTC3350 Typical Application


The LTC®3350 is a backup power controller that can charge and monitor a series stack of one to four supercapacitors. The LTC3350’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 can run 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 LTC3350 monitors system voltages, currents, stack capacitance and stack ESR which can all be read over the I2C/SMBus. The dual ideal diode controller uses N-channel MOSFETs for low loss power paths from the input and supercapacitors to the backup system supply. The LTC3350 is available in a low profile 38-lead 5mm × 7mm × 0.75mm QFN surface mount package.


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

Part Number Package Code Temp Package
LTC3350EUHF#PBF 5x7 QFN-38 UHF E 05-08-1701 RoHS
LTC3350EUHF#TRPBF 5x7 QFN-38 UHF E 05-08-1701 RoHS
LTC3350IUHF#PBF 5x7 QFN-38 UHF I 05-08-1701 RoHS
LTC3350IUHF#TRPBF 5x7 QFN-38 UHF I 05-08-1701 RoHS

LTC3350 Package Drawing

Order Info

Package Variations and Pricing

Part Number Package Temp Price
LTC3350EUHF#PBF 5x7 QFN-38 E $7.50 $5.25 View
LTC3350EUHF#TRPBF 5x7 QFN-38 E $5.31 View
LTC3350IUHF#PBF 5x7 QFN-38 I $8.29 $5.80 View
LTC3350IUHF#TRPBF 5x7 QFN-38 I $5.86 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
DC1937B LTC3350EUHF Demo Board | High Current Supercapacitor Backup Controller and System Monitor, up to 20Vin $200.00
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Companion Boards

Part Number Description Price Documentation
DC590B USB Serial Controller for Linear Technology QuikEval Demo Boards $50.00
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Click here to view our complete list of demo boards


  • High Current 12V Ride-Through UPS
  • Servers/Mass Storage/High Availability Systems

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Design Tools


The Linear Technology LTC6954_GUI is used to communicate with the LTC6954 clock driver. It uses the DC590 to translate between USB and SPI-compatible serial communications formats.

Click here to download LTC6954_GUI


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