LTC3555/LTC3555-X - High Efficiency USB Power Manager + Triple Step-Down DC/DC
Features
-
POWER MANAGER
- High Efficiency Switching PowerPath™ Controller with Bat-Track™ Adaptive Output Control
- Programmable USB or Wall Current Limit (100mA/500mA/1A)
- Full Featured Li-Ion/Polymer Battery Charger
- 1.5A Maximum Charge Current
- Internal 180mΩ Ideal Diode + External Ideal Diode Controller Powers Load in Battery Mode
- Low No-Load Quiescent Current when Powered from BAT (<32µA)
DC/DCs
- Triple High Efficiency Step-Down DC/DCs (1A/400mA/400mA IOUT)
- All Regulators Operate at 2.25MHz
- Dynamic Voltage Scaling on Two Outputs
- I2C or Independent Enable, VOUT Controls
- Low No-Load Quiescent Current: 20µA
- 28-Pin (4mm × 5mm × 0.75mm) QFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages
Typical Application
Description
The LTC3555 family are highly integrated USB com- patible power management and battery charger ICs for Li-Ion/Polymer battery applications. They include a high efficiency current limited switching PowerPath manager with automatic load prioritization, a battery charger, an ideal diode and three general purpose synchronous step-down switching regulators.The LTC3555 family limits input current to either 100mA or 500mA for USB applications or 1A for adapter-powered applications. Unlike linear chargers, the LTC3555 family’s switching architecture transmits nearly all of the power avail- able from the USB port to the load with minimal loss and heat which eases thermal constraints in small spaces.
Two of the three general purpose switching regulators can provide up to 400mA and the third can deliver 1A. The entire product can be controlled via I2C or simple I/O. The LTC3555-1/LTC3555-3 versions offer “instant-on” power delivery to the portable product even with a very low battery voltage. The LTC3555-3 version also has a reduced charger float voltage of 4.100V for battery safety and longevity.
The LTC3555 family is available in the low profile 28-pin (4mm × 5mm × 0.75mm) QFN surface mount 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 |
|---|---|---|---|---|---|
| LTC3555EUFD-1#PBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LTC3555EUFD-1#TRPBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LTC3555EUFD-3#PBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LTC3555EUFD-3#TRPBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LTC3555EUFD#PBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LTC3555EUFD#TRPBF | 4x5 QFN-28 | UFD | E | 05-08-1712 | Yes |
| LTC3555IUFD-1#PBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | Yes |
| LTC3555IUFD-1#TRPBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | Yes |
| LTC3555IUFD-3#PBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | Yes |
| LTC3555IUFD-3#TRPBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | Yes |
| LTC3555IUFD#PBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | Yes |
| LTC3555IUFD#TRPBF | 4x5 QFN-28 | UFD | I | 05-08-1712 | 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 | |
|---|---|---|---|---|---|---|
| LTC3555EUFD-1#PBF | 4x5 QFN-28 | E | $6.64 | $4.65 | Yes | |
| LTC3555EUFD-1#TRPBF | 4x5 QFN-28 | E | $4.71 | Yes | ||
| LTC3555EUFD-3#PBF | 4x5 QFN-28 | E | $6.64 | $4.65 | Yes | |
| LTC3555EUFD-3#TRPBF | 4x5 QFN-28 | E | $4.71 | Yes | ||
| LTC3555EUFD#PBF | 4x5 QFN-28 | E | $6.64 | $4.65 | Yes | |
| LTC3555EUFD#TRPBF | 4x5 QFN-28 | E | $4.71 | Yes | ||
| LTC3555IUFD-1#PBF | 4x5 QFN-28 | I | $7.64 | $5.35 | Yes | |
| LTC3555IUFD-1#TRPBF | 4x5 QFN-28 | I | $5.41 | Yes | ||
| LTC3555IUFD-3#PBF | 4x5 QFN-28 | I | $7.64 | $5.35 | Yes | |
| LTC3555IUFD-3#TRPBF | 4x5 QFN-28 | I | $5.41 | Yes | ||
| LTC3555IUFD#PBF | 4x5 QFN-28 | I | $7.64 | $5.35 | Yes | |
| LTC3555IUFD#TRPBF | 4x5 QFN-28 | I | $5.41 | 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 |
|---|---|---|---|
| DC1020A | LTC3555| High Effiency USB Power Manager + Triple Buck | $175.00 | |
| DC1376A-A | LTC3555EUFD | High Efficiency USB Power Manager plus Triple Buck DC/DC | Contact Factory | |
| DC1376A-B | LTC3555EUFD | High Efficiency USB Power Manager plus Triple Buck DC/DC | Contact Factory | |
| Buy Now | |||
Companion Boards
| Part Number | Description | Price | Documentation |
|---|---|---|---|
| DC590B | Isolated USB Serial Controller for Linear Technology QuikEval-Compatible Demo Boards | $50.00 | |
| 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 | |
|---|---|---|---|---|---|---|
| LTC3555IUFD-1#PBF | 4x5 QFN-28 | I | $7.64 | $5.35 | Yes | |
| LTC3555IUFD-1#TRPBF | 4x5 QFN-28 | I | $5.41 | Yes | ||
| LTC3555IUFD-3#PBF | 4x5 QFN-28 | I | $7.64 | $5.35 | Yes | |
| LTC3555IUFD-3#TRPBF | 4x5 QFN-28 | I | $5.41 | Yes | ||
| LTC3555IUFD#PBF | 4x5 QFN-28 | I | $7.64 | $5.35 | Yes | |
| LTC3555IUFD#TRPBF | 4x5 QFN-28 | I | $5.41 | Yes | ||
| Buy Now • Request Samples | ||||||
Applications
- HDD-Based MP3 Players, PDAs, GPS, PMPs
- Portable Medical Products
- Handheld Instrumentation
- Other USB-Based Handheld Products
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Product Notifications
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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.
