LTC4061-4.4_15 Datasheet, PDF (1/20 Pages) Linear Technology – Standalone Linear Li-Ion Battery Charger with Thermistor Input

FEATURES
■ _{Charge Current Programmable Up to 1A}
■ _{Charges Single-Cell Li-Ion Batteries Directly from}
USB Port
■ _{Preset 4.375V Float Voltage with ±0.4% Accuracy}
■ _{Thermistor Input for Temperature Qualified}
Charging
■ _{Input Supply Present Logic Output}
■ _{Thermal Regulation Maximizes Charge Rate}
Without Risk of Overheating
■ _{Programmable Charge Current Detection/}
Termination
■ _{Programmable Charge Termination Timer}
■ _{Smart Pulsing Error Feature}
■ _SmartStart^TM _{Prolongs Battery Life}
■ _{20µA Charger Quiescent Current in Shutdown}
■ _{Available in a Low Profile (0.75mm) 10-Lead}
(3mm × 3mm) DFN Package
U
APPLICATIO S
■ _{Handheld Computers}
■ _{Portable MP3 Players}
■ _{Digital Cameras}
LTC4061-4.4
Standalone Linear Li-Ion Battery
Charger with Thermistor Input
DESCRIPTIO
The LTC^®4061-4.4 is a full-featured, flexible, standalone
linear charger for single-cell 4.375V Lithium-Ion batteries. It
is capable of operating within USB power specifications.
Both programmable time and programmable current
based termination schemes are available. Furthermore,
the CHRG open-drain status pin can be programmed to
indicate the battery charge state according to the needs
of the application. Additional safety features designed to
maximize battery lifetime and reliability include NTC bat-
tery temperature sensing and the SmartStart charging
algorithm.
No external sense resistor or external blocking diode is
required for charging due to the internal MOSFET archi-
tecture. Internal thermal feedback regulates the charge
current to maintain a constant die temperature during high
power operation or high ambient temperature conditions.
The charge current is programmed with an external resis-
tor. With power applied, the LTC4061-4.4 can be put into
shutdown mode to reduce the supply current to 20µA and
the battery drain current to less than 5µA.
Other features include smart recharge, USB C/5 cur-
rent programming input, undervoltage lockout and AC
Present logic output.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
SmartStart is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 6522118.
TYPICAL APPLICATIO
V_IN
4.5V TO 8V
800mA Single-Cell Li-Ion Battery Charger
(C/10 Termination)
1µF
619Ω
V_CC
BAT
EN
C/5
CHRG
LTC4061-4.4
TIMER ACPR
PROG
I_DET
NTC
GND
800mA
+ ^4.4V
SINGLE-CELL
Li-Ion BATTERY*
*SANYO BATTERIES:
UF553436T OR
UF553450T
40614.4 TA01a
Complete Charge Cycle (1100mAh Battery)
900
4.5
800
4.4
700
4.3
600 ^BATTERY
VOLTAGE
500
400
300
4.2
4.1
BATTERY
CURRENT
4.0
3.9
200
100 ^VCC ^{= 5V}
T_A = 25°C
0
0
0.5 1.0 1.5 2.0
TIME (HOURS)
3.8
3.7
3.6
2.5
40614.4 TA01b
406144fb
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