LTC4065A_15 Datasheet, PDF (1/16 Pages) Linear Technology – Standalone 750mA Li-Ion Battery Charger

LTC4065/LTC4065A
Standalone 750mA Li-Ion
Battery Charger in 2 × 2 DFN
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 4.2V Float Voltage with 0.6% Accuracy}
■ _{Constant-Current/Constant-Voltage Operation with}
Thermal Feedback to Maximize Charging Rate
Without Risk of Overheating
■ _{ACPR Pin Indicates Presence of Input Supply}
(LTC4065A Only)
■ _{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}
U
APPLICATIO S
■ _{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.
DESCRIPTIO
The LTC^®4065 is a complete constant-current/constant-
voltage linear charger for single-cell lithium-ion batteries.
Its 2mm × 2mm DFN package and low external component
count make the LTC4065 especially well-suited for por-
table applications. Furthermore, LTC4065 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-
turer specifications.
No external sense resistor or blocking diode is required
due to the internal MOSFET architecture. Thermal feed-
back 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 automatically enters a low current
state, dropping battery drain current to less than 1µA. With
power applied, LTC4065 can be put into shutdown mode,
reducing the supply current to less than 20µA.
The full-featured LTC4065 also includes automatic re-
charge, low-battery charge conditioning (trickle charg-
ing), soft-start (to limit inrush current) and an open-drain
status pin to indicate the presence of an adequate input
voltage (LTC4065A only).
The LTC4065 is available in a tiny 6-lead, low profile
(0.75mm) 2mm × 2mm DFN package.
TYPICAL APPLICATIO
Standalone Li-Ion Battery Charger
V_IN
4.3V TO 5.5V
C1
1µF
R2*
1Ω
R1
510Ω
V_CC BAT
LTC4065
CHRG PROG
EN GND
500mA
+ ^4.2V
Li-Ion
R3 ^BATTERY
2k
4065 TA01
*SERIES 1Ω RESISTOR ONLY NEEDED FOR INDUCTIVE INPUT SUPPLIES
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