LTC4078/LTC4078X- Dual Input Li-Ion Battery Charger with Overvoltage Protection

Features

  • 22V Maximum Voltage for Wall Adapter and USB Inputs
  • Charge Single-Cell Li-Ion Batteries from Wall Adapter and USB Inputs
  • Automatic Input Power Detection and Selection
  • Charge Current Programmable Up to 950mA from Wall Adapter Input
  • Overvoltage Lockout for Wall Adapter and USB Inpu
  • Battery Detection Input Disables Charger When N Battery is Present
  • No External MOSFET, Sense Resistor or Blocking Diode Needed
  • Thermal Regulation Maximizes Charge Rate Without Risk of Overheating
  • Preset Charge Voltage with ±0.6% Accuracy
  • Programmable Charge Current Termination
  • 40µA USB Suspend Current in Shutdown
  • Charge Status Output
  • Automatic Recharge
  • Available Without Trickle Charge (LTC4078X)
  • Available in a Thermally Enhanced, Low Profile (0.75mm) 10-Lead (3mm x 3mm) DFN Package

Typical Application

LTC4078 Typical Application
LTC4078 Typical Application

Description

The LTC4078/LTC4078X are standalone linear chargers that are capable of charging a single-cell Li-Ion/Polymer battery from both wall adapter and USB inputs. The chargers can detect power at the inputs and automatically select the appropriate power source for charging.

No external sense resistor or blocking diode is required for charging due to the internal MOSFET architecture. The LTC4078/LTC4078X feature a maximum 22V rating for both wall adapter and USB inputs, although charging stops if the selected power source exceeds the overvoltage limit. Internal thermal feedback regulates the battery charge current to maintain a constant die temperature during high power operation or high ambient temperature conditions. The float voltage is fixed at 4.2V and the charge current is programmed with an external resistor. The LTC4078/LTC4078X terminate the charge cycle when the charge current drops below the programmed termination threshold after the final float voltage is reached.

Other features include battery present detection, automatic recharge, undervoltage lockout, charge status outputs, and “power present” status outputs to indicate the presence of wall adapter or USB power. The device is offered in a low profile (0.75mm) 3mm × 3mm 10-lead 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
LTC4078EDD-2#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC4078EDD-2#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC4078EDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC4078EDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC4078XEDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LTC4078XEDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes


LTC4078 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
LTC4078EDD-2#PBF 3x3 DFN-10 E $2.86 $2.00 Yes
LTC4078EDD-2#TRPBF 3x3 DFN-10 E $2.06 Yes
LTC4078EDD#PBF 3x3 DFN-10 E $2.86 $2.00 Yes
LTC4078EDD#TRPBF 3x3 DFN-10 E $2.06 Yes
LTC4078XEDD#PBF 3x3 DFN-10 E $2.86 $2.00 Yes
LTC4078XEDD#TRPBF 3x3 DFN-10 E $2.06 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

  • Cellular Telephones
  • Handheld Computers
  • Portable MP3 Players
  • Digital Cameras

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Technical Support