LTC3225 - 150mA Supercapacitor Charger

Features

  • Low Noise Constant Frequency Charging of Two Series Supercapacitors
  • Automatic Cell Balancing Prevents Capacitor Overvoltage During Charging
  • Programmable Charge Current (Up to 150mA)
  • Selectable 2.4V or 2.65V Regulation per Cell (LTC3225)
  • Selectable 2V or 2.25V Regulation per Cell (LTC3225-1)
  • Automatic Recharge
  • IVIN = 20μA in Standby Mode
  • ICOUT < 1μA When Input Supply is Removed
  • No Inductors
  • Tiny Application Circuit (2mm × 3mm DFN Package, All Components <1mm High)

Typical Application

LTC3225 Typical Application
LTC3225 Typical Application

Description

The LTC3225/LTC3225-1 are programmable supercapacitor chargers designed to charge two supercapacitors in series to a selectable fixed output voltage (4.8V/5.3V for the LTC3225 and 4V/4.5V for the LTC3225-1) from input supplies as low as 2.8V to 5.5V. Automatic cell balancing prevents overvoltage damage to either supercapacitor. No balancing resistors are required.

Low input noise, low quiescent current and low external parts count (one flying capacitor, one bypass capacitor at VIN and one programming resistor) make the LTC3225/ LTC3225-1 ideally suited for small battery-powered applications.

Charge current level is programmed with an external resistor. When the input supply is removed, the LTC3225/ LTC3225-1 automatically enter a low current state, drawing less than 1μA from the supercapacitors.

The LTC3225/LTC3225-1 are available in a 10-lead 2mm × 3mm DFN package.

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
LTC3225EDDB-1#PBF 3x2 DFN-10 DDB E 05-08-1722 Yes
LTC3225EDDB-1#TRMPBF 3x2 DFN-10 DDB E 05-08-1722 Yes
LTC3225EDDB-1#TRPBF 3x2 DFN-10 DDB E 05-08-1722 Yes
LTC3225EDDB#PBF 3x2 DFN-10 DDB E 05-08-1722 Yes
LTC3225EDDB#TRMPBF 3x2 DFN-10 DDB E 05-08-1722 Yes
LTC3225EDDB#TRPBF 3x2 DFN-10 DDB E 05-08-1722 Yes


LTC3225 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
LTC3225EDDB-1#PBF 3x2 DFN-10 E $2.86 Yes
LTC3225EDDB-1#TRMPBF 3x2 DFN-10 E $2.86 $2.05 Yes
LTC3225EDDB-1#TRPBF 3x2 DFN-10 E $2.86 $2.00 Yes
LTC3225EDDB#PBF 3x2 DFN-10 E $2.86 Yes
LTC3225EDDB#TRMPBF 3x2 DFN-10 E $2.86 $2.05 Yes
LTC3225EDDB#TRPBF 3x2 DFN-10 E $2.86 $2.00 Yes
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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
DC1220B LTC3225EDDB DEMO BOARD| 150mA Supercapacitor Charger $125.00
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Click here to view our complete list of demo boards

Applications

  • Current Limited Applications with High Peak Power Loads (LED Flash, PCMCIA Tx Bursts, HDD Bursts, GPRS/GSM Transmitter)
  • Backup Supplies

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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 IV:
LTC3225
LTC3225-1

Technical Support