LINEAR LTC3225 User's Manual
Summary
Supercapacitors are advanced energy storage solutions designed for applications requiring high power density and extreme cycle life, making them superior to traditional batteries in many scenarios. This manual provides comprehensive technical guidance on integrating supercaps into robust power management systems. It covers essential components such as specialized chargers, DC/DC controllers, ideal diode circuits, and complete design strategies, focusing particularly on reliable power ride-through applications. This resource is essential for electrical engineers, system designers, and power professionals building resilient equipment that demands constant, dependable energy backup.
Page 1 Text Content
LINEAR TECHNOLOGY SEPTEMBER 2008 VOLUME XVIII NUMBER 3 IN THIS ISSUE… Replace Batteries in COVER ARTICLE Replace Batteries in Power Ride- Power Ride-Through Through Applications with Robust Supercaps and 3mm × 3mm Capacitor Charger ..............................1 Jim Drew Applications with Linear in the News… ...........................2
DESIGN FEATURES Robust Supercaps
New Family of Integrated Power Controllers Combine Fast Battery
Charging, Power Path™ Control and 3mm × 3mm
and Efficient DC/DC Converters in Less Than 20mm2 ..........................4 Sam Nork Capacitor Charger Charging and Discharging Methods
by Jim Drew
That Extend Li-Ion Battery Life ...........7 Introduction Fran Hoffart
Supercapacitors (or ultracapacitors)
Serial Interface for High Speed Data
are finding their way into an increasing
One advantage
Converters Simplifies Layout over
Traditional Parallel Devices .............13 number of applications for short-
supercapacitors have over
Clarence Mayott term energy storage and applications
batteries is their long life.
Synchronous Buck Controller in that require intermittent high energy
3mm × 3mm QFN Fits Automotive and A capacitor’s cycle life is
pulses. One such application is a
Industrial Applications with 4V–38V
power ride-through circuit, in which quoted as greater than
Input Capability ................................16 Mark Mercer a backup energy source cuts in and 500,000 cycles; batteries
powers the load if the main power
Feature-Packed Charger Handles All are specified for only a few
Battery Chemistries and Produces supply fails for a short time. This type
hundred cycles. This makes
3A/50W for Fast Charging from a
of application has been dominated
4mm × 4mm QFN ...............................18 the supercapacitor an ideal
James A. Mc Kenzie by batteries in the past, but electric
“set and forget” device,
double layer capacitors (EDLCs) are
Dual Hot Swap™ Controller in
fast making inroads as their price- requiring little or
3mm × 2mm DFN is Perfect for Backplane or Card Resident
per-farad, size and effective series no maintenance.
1V–6V Applications ..........................21
resistance per capacitance (ESR/C)
CY Lai
continue to fall.
0V to 18V Ideal Diode Controller Saves
In a power ride-through applica- charging current, automatic cell volt-
Watts and Space over Schottky .........24 Pinkesh Sachdev tion, series-stacked capacitors must age balancing, low drain current on the
be charged and cell-voltage balanced. supercapacitors and a patent pending,
Low Voltage, High Current Step-Down µModule™ Regulators Put a (Nearly) Supercaps are switched into the power low noise, constant current charger. Complete Power Supply in a
path when needed and the power to
15mm × 9mm × 2.8mm Package ........28
the load is controlled by a DC/DC Supercapacitor
Judy Sun, Sam Young and Henry Zhang
converter. The LTC3225 supercapaci- Characteristics
DESIGN IDEAS
tor charger has a number of features Supercapacitors come in a variety of
that make it a good choice for power sizes, for example a 10F/2.7V super-
(complete list on page 30)
ride-through applications. It comes cap is available in a 10mm × 30mm
New Device Cameos ...........................37
in a small, 10-lead 3mm × 3mm DFN 2-terminal radial can with an ESR of
Design Tools ......................................39 package and features programmable continued on page Sales Offices .....................................40
L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, Over-The-Top and Poly Phase are registered trademarks of Linear Technology Corporation. Adaptive Power, Bat-Track, Bode CAD, C-Load, Direct Sense, Easy Drive, Filter CAD, Hot Swap, Linear View, µModule, Micropower Switcher CAD, Multimode Dimming, No Latency ΔΣ, No Latency Delta-Sigma, No RSENSE, Operational Filter, Panel Protect, Power Path, Power SOT, Smart Start, Soft Span, Stage Shedding, Switcher CAD, Thin SOT, Timer Blox, True Color PWM, Ultra Fast and VLDO are trademarks of Linear Technology Corporation. Other product names may be trademarks of the companies that manufacture the products.
Page Summary Contents For LINEAR LTC3225 User's Manual
Manual Details
| Brand | Linear |
|---|---|
| Pages | 3 |
| File Size | 182.67 KB |
| Published | May 29, 2026 |
Enter the captcha to get the download link:
Frequently Asked Questions
What advantage do supercapacitors offer over traditional batteries?
Supercapacitors provide a significantly longer lifespan, with cycle lives often quoted as greater than 500,000 cycles.
How are supercapacitors used for power ride-through?
They function as a backup energy source, providing continuous power to the load if the main electrical supply fails temporarily.
What is required when using series-connected capacitors?
Series-stacked capacitors must be addressed with cell balancing methods to ensure proper voltage distribution and maintain longevity.
What wide range of voltages can these power controllers manage?
Available designs support a versatile range of voltages, such as 0V to 18V or even up to 4V–38V.