LTC4081 - 500mA Li-Ion Charger with NTC Input and 300mA Synchronous Buck

Features

Battery Charger:

  • Constant-Current/Constant-Voltage Operation with Thermal Feedback to Maximize Charge Rate without Risk of Overheating
  • Internal 4.5-Hour Safety Timer for Termination
  • Charge Current Programmable Up to 500mA with 5% Accuracy
  • NTC Thermistor Input for Temperature Qualified Charging
  • C/10 Charge Current Detection Output
  • 5µA Supply Current in Shutdown Mode

Switching Regulator:

  • High Efficiency Synchronous Buck Converter
  • 300mA Output Current (Constant-Frequency Mode)
  • 2.7V to 4.5V Input Range (Powered from BAT Pin)
  • 0.8V to VBAT Output Range
  • MODE Pin Selects Fixed (2.25MHz) Constant-Frequency PWM Mode or Low ICC (23µA) Burst Mode® Operation
  • 2µA BAT Current in Shutdown Mode
  • 10-Lead, Low Profile (0.75 mm) 3mm × 3mm DFN Package

Typical Application

LTC4081 Typical Application
LTC4081 Typical Application

Description

The LTC®4081 is a complete constant-current/constantvoltage linear battery charger for a single-cell 4.2V lithium-ion/polymer battery with an integrated 300mA synchronous buck converter. A 3mm × 3mm DFN package and low external component count make the LTC4081 especially suitable for portable applications. Furthermore, the LTC4081 is specifically designed to work within USB power specifications.

The CHRG pin indicates when charge current has dropped to ten percent of its programmed value (C/10). An internal 4.5-hour timer terminates the charge cycle. The fullfeatured LTC4081 battery charger also includes trickle charge, automatic recharge, soft-start (to limit inrush current) and an NTC thermistor input used to monitor battery temperature.

The LTC4081 integrates a synchronous buck converter that is powered from the BAT pin. It has an adjustable output voltage and can deliver up to 300mA of load current. The buck converter also features low current high efficiency Burst Mode operation that can be selected by the MODE pin.

The LTC4081 is available in a 10-lead, low profile (0.75mm) 3mm × 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
LTC4081EDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC4081EDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes


LTC4081 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
LTC4081EDD#PBF 3x3 DFN-10 E $2.71 $1.90 Yes
LTC4081EDD#TRPBF 3x3 DFN-10 E $1.96 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.

Click here to view our complete list of demo boards

Applications

  • Wireless Headsets
  • Bluetooth Applications
  • Portable MP3 Players
  • Multifunction Wristwatches

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