LTC4065-4.4 - Standalone 750mA Li-Ion Battery Charger in 2 × 2 DFN

The LTC4065-4.4 is a complete constant-current/constant- voltage linear charger for high capacity single-cell lithium-ion batteries with a 4.4V float voltage. Its 2mm × 2mm DFN package and low external component count make the LTC4065-4.4 especially well-suited for portable applications. Furthermore, LTC4065-4.4 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 timer terminates charging according to battery manufacturer specifications.

No external sense resistor or blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates charge current to limit the die temperature during high power operation or high ambient temperature conditions.

When the input supply (wall adapter or USB supply) is removed, the LTC4065-4.4 automatically enters a low current state, dropping battery drain current to less than 1µA. With power applied, LTC4065-4.4 can be put into shutdown mode, reducing the supply current to less than 20µA.

The full-featured LTC4065-4.4 also includes automatic recharge, low-battery charge conditioning (trickle charging) and soft-start (to limit inrush current).

The LTC4065-4.4 is available in a tiny 6-lead, low profile (0.75mm) 2mm × 2mm DFN package.

Features

Complete Linear Charger in 2mm × 2mm DFN Package
C/10 Charge Current Detection Output
Timer Termination
Charge Current Programmable Up to 750mA with 5% Accuracy
No External MOSFET, Sense Resistor or Blocking Diode Required
Preset 4.4V Float Voltage with 0.6% Accuracy
Constant-Current/Constant-Voltage Operation with Thermal Feedback to Maximize Charging Rate
Without Risk of Overheating
Charge Current Monitor Output for Gas Gauging
Automatic Recharge
Charges Single-cell Li-Ion Batteries Directly from USB Port
20µA Supply Current in Shutdown Mode
Soft-Start Limits Inrush Current
Tiny 6-Lead (2mm × 2mm) DFN Package