LTC4055/LTC4055-1 - USB Power Controller and Li-Ion Linear Charger

Features

  • Charges Single Cell Li-Ion Batteries Directly from USB Port
  • Load Dependent Charging Guarantees USB Input Current Compliance
  • Automatic Battery Switchover When Input Supply is Removed
  • Constant-Current/Constant-Voltage Operation with Thermal Feedback to Maximize Charging Rate Without Risk of Overheating*
  • Selectable 500mA/100mA Current Limit
  • Low Loss Full PowerPath™ Control with Ideal Diode Operation (Reverse Current Blocking)
  • Preset 4.2V Charge Voltage with 0.8% Accuracy (4.1V for LTC4055-1)
  • 4.1V Float Voltage (LTC4055-1) Improves Battery Life and High Temperature Safety Margin
  • USB Compliant Suspend Mode
  • Programmable Charge Current and Termination Timer
  • Soft-Start Limits Inrush Current
  • NTC Thermistor Input for Temperature Qualified Charging
  • Tiny (4mm x 4mm x 0.75mm) QFN Package

Typical Application

LTC4055 Typical Application
LTC4055 Typical Application

Description

The LTC4055/LTC4055-1 are USB power manager and Li-Ion battery chargers designed to work in portable battery-powered applications. The parts manage and limit the total current used by the USB peripheral for operation and battery charging. Depending on the state of the current select pin (HPWR), total input current can be limited to either 100mA or 500mA. The voltage drop from the USB supply or battery to the USB peripheral is typically less than 100mV at 400mA and 20mV at 80mA. Other management features include: automatic switch over to battery when input is removed, inrush current limiting, reverse current blocking, undervoltage lockout and thermal shutdown.

The LTC4055/LTC4055-1 include a complete constant- current/constant-voltage linear charger for single cell Li-ion batteries. The float voltage applied to the battery is held to a tight 0.8% tolerance, and charge current is programmable using an external resistor to ground. Fully discharged cells are automatically trickle charged at 10% of the programmed current until the cell voltage exceeds 2.8V. Total charge time is programmable by an external capacitor to ground. When the battery drops 100mV be- low the float voltage, automatic recharging of the battery occurs. Also featured is an NTC thermistor input used to monitor battery temperature while charging.

The LTC4055/LTC4055-1 are available in a 16-pin low profile (4mm x 4mm) QFN 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
LTC4055EUF-1#PBF 4x4 QFN-16 UF E 05-08-1692 Yes
LTC4055EUF-1#TRPBF 4x4 QFN-16 UF E 05-08-1692 Yes
LTC4055EUF#PBF 4x4 QFN-16 UF E 05-08-1692 Yes
LTC4055EUF#TRPBF 4x4 QFN-16 UF E 05-08-1692 Yes


LTC4055 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
LTC4055EUF-1#PBF 4x4 QFN-16 E $3.14 $2.20 Yes
LTC4055EUF-1#TRPBF 4x4 QFN-16 E $2.26 Yes
LTC4055EUF#PBF 4x4 QFN-16 E $3.13 $2.20 Yes
LTC4055EUF#TRPBF 4x4 QFN-16 E $2.30 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
DC676A LTC4055EUF | USB Power Controller and Li-Ion Charger, Adapter Input = 4.5V to 5.5V, USB Input = 4.35V to 5.5V $150.00
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Click here to view our complete list of demo boards

Applications

  • Portable USB Devices: Cameras, MP3 Players, PDAs

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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