Standalone 750mA Li-Ion
Battery Charger in 2 × 2 DFN
■ Complete Linear Charger in 2mm × 2mm DFN
■ C/10 Charge Current Detection Output
■ Timer Termination
■ Charge Current Programmable Up to 750mA with
■ No External MOSFET, Sense Resistor or Blocking
■ 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
■ 20µA Supply Current in Shutdown Mode
■ Soft-Start Limits Inrush Current
■ Tiny 6-Lead (2mm × 2mm) DFN Package
■ Wireless PDAs
■ Cellular Phones
■ Portable Electronics
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents,
including 6522118, 6700364.
The LTC®4065-4.4 is a complete constant-current/con-
stant-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 manufac-
No external sense resistor or blocking diode is required due
to the internal MOSFET architecture. Thermal feedback regu-
lates 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 cur-
rent state, dropping battery drain current to less than
1µA. With power applied, LTC4065-4.4 can be put into shut-
down mode, reducing the supply current to less than 20µA.
The full-featured LTC4065-4.4 also includes automatic
recharge, low-battery charge conditioning (trickle charg-
ing) 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.
Standalone Li-Ion Battery Charger
*E.G. SANYO BATTERIES: UF553436T OR UF553450T
Complete Charge Cycle (1100mAh Battery)
VCC = 5V
RPROG = 2K
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5