The LTC4059/LTC4059AEDC are constant-current/constant-voltage linear chargers for single cell lithium-ion batteries. Their 2mm × 2mm DFN package and low external component count make these chargers especially well suited for portable applications. Furthermore, they are designed to work within USB power specifications.
No external sense resistor, MOSFET or blocking diode is required. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient thermal conditions. The charge voltage is fixed at 4.2V and the charge current is programmable.
When the input supply (wall adapter or USB supply) is removed, the LTC4059/LTC4059AEDC automatically enter a low current state, dropping the battery current drain to less than 1μA. With power applied, they can be put into shutdown mode, reducing the supply current to 10μA.
The LTC4059AEDC features an open-drain status pin to indicate the presence of an input voltage. The LTC4059 can be used as a constant-current source to charge Nickel cells. Other features include undervoltage lockout protection and a current monitor pin which can indicate when to terminate a charge cycle.
The LTC4059/LTC4059AEDC are available in a 6-lead, low profile (0.75mm) 2mm × 2mm DFN package.
Feature
- Programmable Charge Current Up to 900mA
- Charge Current Monitor Output for Charge Termination
- Constant-Current/Constant-Voltage Operation with Thermal Regulation to Maximize Charging Rate Without Risk of Overheating
- Constant-Current Source Mode for Charging Nickel Batteries (LTC4059 Only)
- ACPR Pin Indicates Presence of Input Supply (LTC4059A Only)
- No External MOSFET, Sense Resistor or Blocking Diode Required
- Operating Supply Voltage from 3.75V to 8V
- Charges Single Cell Li-Ion Batteries Directly from USB Port
- Preset 4.2V Charge Voltage with 0.6% Accuracy
- 10μA Supply Current in Shutdown Mode
- Tiny 6-Lead (2mm × 2mm) DFN Package
Applications
- Wireless PDAs
- Cellular Phones
- Portable Electronics
- Wireless Headsets
- Digital Cameras
(Picture: Pinout)
