LTC4425 - Linear SuperCap Charger with Current-Limited Ideal Diode and V/I Monitor
Features
- 50mΩ Ideal Diode from VIN to VOUT
- Smart Charge Current Profile Limits Inrush Current
- Internal Cell Balancer (No External Resistors)
- Programmable Output Voltage (LDO Mode)
- Programmable VIN to VOUT Current Limit
- Continuous Monitoring of VIN to VOUT Current via PROG Pin
- Low Quiescent Current: 20μA
- VIN Power Fail, PGOOD Indicator
- 2.45V/2.7V Cell Protection Shunts
(4.9V/5.4V SuperCap Max Top-Off Voltage) - 3A Peak Current Limit, Thermal Limiting
- Tiny Application Circuit, 3mm × 3mm × 0.75mm DFN and 12-Lead MSOP Packages
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC4425 is a constant-current/constant-voltage linear charger designed to charge a 2-cell supercap stack from either a Li-Ion/Polymer battery, a USB port, or a 2.7V to 5.5V current-limited supply. The part operates as an ideal diode with an extremely low 50mΩ on-resistance making it suitable for high peak-power/low average power applications. The LTC4425 charges the output capacitors to an externally programmed output voltage in LDO mode at a constant charge current, or to VIN in normal mode with a smart charge current profile to limit the inrush current until the VIN to VOUT differential is less than 250mV. In addition the LTC4425 can be set to clamp the output voltage to 4.9V or 5.4V.
Charge current (VOUT current limit) is programmed by connecting a resistor between PROG and GND. The voltage on the PROG pin represents the current fl owing from VIN to VOUT for current monitoring. An internal active balancing circuit maintains equal voltages across each supercapacitor and clamps the peak voltage across each cell to a pin-selectable maximum value. The LTC4425 operates at a very low 20μA quiescent current (shutdown current <3μA) and is available in a low profile 12-pin 3mm × 3mm DFN or a 12-lead MSOP 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 |
|---|---|---|---|---|---|
| LTC4425EDD#PBF | 3x3 DFN-12 | DD | E | 05-08-1725 | Yes |
| LTC4425EDD#TRPBF | 3x3 DFN-12 | DD | E | 05-08-1725 | Yes |
| LTC4425EMSE#PBF | MS-12E | MSE | E | 05-08-1666 | Yes |
| LTC4425EMSE#TRPBF | MS-12E | MSE | E | 05-08-1666 | Yes |
| LTC4425IDD#PBF | 3x3 DFN-12 | DD | I | 05-08-1725 | Yes |
| LTC4425IDD#TRPBF | 3x3 DFN-12 | DD | I | 05-08-1725 | Yes |
| LTC4425IMSE#PBF | MS-12E | MSE | I | 05-08-1666 | Yes |
| LTC4425IMSE#TRPBF | MS-12E | MSE | I | 05-08-1666 | Yes |
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 | |
|---|---|---|---|---|---|---|
| LTC4425EDD#PBF | 3x3 DFN-12 | E | $3.22 | $2.25 | Yes | |
| LTC4425EDD#TRPBF | 3x3 DFN-12 | E | $2.31 | Yes | ||
| LTC4425EMSE#PBF | MS-12E | E | $3.36 | $2.35 | Yes | |
| LTC4425EMSE#TRPBF | MS-12E | E | $2.41 | Yes | ||
| LTC4425IDD#PBF | 3x3 DFN-12 | I | $3.71 | $2.60 | Yes | |
| LTC4425IDD#TRPBF | 3x3 DFN-12 | I | $2.66 | Yes | ||
| LTC4425IMSE#PBF | MS-12E | I | $3.86 | $2.70 | Yes | |
| LTC4425IMSE#TRPBF | MS-12E | I | $2.76 | Yes | ||
| Buy Now • Request Samples | ||||||
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 |
|---|---|---|---|
| DC1589A | LTC4425EDD Demo Board | Linear SuperCap Charger with Current-Limited Ideal Diode and V/I Monitor | $100.00 | |
| Buy Now | |||
Designed for Automotive and Transportation Applications
AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports or to inquire about parts that are not included. For more information, view our Automotive and Transportation page
| Part Number | Package | Temp | Price (1-99) |
Price (1k)* |
RoHS | |
|---|---|---|---|---|---|---|
| LTC4425IDD#PBF | 3x3 DFN-12 | I | $3.71 | $2.60 | Yes | |
| LTC4425IDD#TRPBF | 3x3 DFN-12 | I | $2.66 | Yes | ||
| LTC4425IMSE#PBF | MS-12E | I | $3.86 | $2.70 | Yes | |
| LTC4425IMSE#TRPBF | MS-12E | I | $2.76 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- High Peak Power Battery/USB Powered Equipment
- Industrial PDAs
- Portable Instruments/Monitoring Equipment
- Power Meters, SuperCap Backup Circuits
- PC Card/USB Modems
People Who Viewed This Product Also Viewed
- LTC3625 - 1A High Efficiency 2-Cell Supercapacitor Charger with Automatic Cell Balancing
- LTC3225 - 150mA Supercapacitor Charger
- LTC3226 - 2-Cell Supercapacitor Charger with Backup PowerPath Controller
- LT3796/LT3796-1 - 100V Constant-Current and Constant-Voltage Controller with Dual Current Sense
- LTC3350 - High Current Supercapacitor Backup Controller and System Monitor
- LT3761/LT3761-1 - 60VIN LED Controller with Internal PWM Generator
- LTC3128 - 3A Monolithic Buck-Boost Supercapacitor Charger and Balancer with Accurate Input Current Limit
- LT4320/LT4320-1 - Ideal Diode Bridge Controller
- LT3652 - Power Tracking 2A Battery Charger for Solar Power
- LTC3105 - 400mA Step-Up DC/DC Converter with Maximum Power Point Control and 250mV Start-Up
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 mylinear@linear.com with questions and comments.
Design Tools
Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:
- LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
- LTpowerCAD - A complete power supply selection, synthesis and design tool
- LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
- PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
- Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
- LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
- And More!
Technical Support
- For immediate technical assistance, contact your local sales office or distributor or call 1-800-4-LINEAR (US customers only) or 408-432-1900.
- For less urgent requests, please complete our Technical Support Request Form. Please allow 2-3 business days for reply.
