LTC4054L-4.2 Datasheet, PDF (1/16 Pages) Linear Technology – 150mA Standalone Linear Li-Ion Battery Charger in ThinSOT

LTC4054L-4.2
150mA Standalone Linear
Li-Ion Battery Charger in ThinSOT
FEATURES
s _{Programmable Charge Current Range:}
10mA to 150mA
s _{No External MOSFET, Sense Resistor or Blocking}
Diode Required
s _{Complete Linear Charger in ThinSOT}^TM _{Package for}
Single Cell/Coin Cell Lithium-Ion Batteries
s _{Constant-Current/Constant-Voltage Operation with}
Thermal Regulation* to Maximize Charge Rate
Without Risk of Overheating
s _{Charges Single Cell Li-Ion Batteries Directly}
from USB Port
s _{Preset 4.2V Charge Voltage with ±1% Accuracy}
s _{Charge Current Monitor Output for Gas Gauging*}
s _{Automatic Recharge}
s _{Charge Status Output Pin}
s _{C/10 Charge Termination}
s _{25µA Max Supply Current in Shutdown Mode}
s _{2.9V Trickle Charge Threshold}
s _{Soft-Start Limits Inrush Current}
s _{Available in a 6-Lead Low Profile (1mm)}
SOT-23 Package
U
APPLICATIO S
s _{Charger for Li-Ion Coin Cell Batteries}
s _{Portable MP3 Players, Wireless Headsets}
s _{Bluetooth Applications}
s _{Multifunction Wristwatches}
DESCRIPTIO
The LTC^®4054L is a complete, constant-current/constant-
voltage linear charger for single cell lithium-ion batteries.
Its small size and ability to regulate low charge currents
make the LTC4054L especially well-suited for portable
applications using low capacity rechargeable lithium-ion
coin cells. Furthermore, the LTC4054L is specifically de-
signed to work within USB power specifications.
No external sense resistor is needed, and no blocking di-
ode is required due to the internal MOSFET architecture.
Thermal feedback regulates the charge current to eliminate
thermal overdesign. The charge voltage is fixed at 4.2V, and
the charge current can be programmed externally with a
single resistor. The LTC4054L automatically terminates a
charge cycle when the charge current drops to 1/10th the
programmed value after the final float voltage is reached.
When the input supply (wall adapter or USB supply) is
removed, the LTC4054L automatically enters a low cur-
rent state, dropping the battery drain current to less than
2µA. The LTC4054L can be put into shutdown mode, re-
ducing the supply current to 25µA.
Other features include charge current monitor, undervoltage
lockout, automatic recharge and a status pin to indicate
charge termination and the presence of an input voltage.
, LTC and LT are registered trademarks of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
*U.S. Patent No. 6,522,118
TYPICAL APPLICATIO
90mA Li-Ion Single Coin Cell Charger
V_IN
4.5V TO 6.5V
1µF
4
V_{CC BAT} 3
LTC4054L-4.2
5
PROG
GND
2
1.69k
90mA
4.2V
COIN CELL
Li-Ion
BATTERY
4054l42 TA01
Complete Charge Cycle (130mAh Battery)
100
4.4
90
CONSTANT
80
CURRENT
70
4.3
4.2
CONSTANT
VOLTAGE
4.1
60
4.0
50
3.9
40
3.8
30
3.7
20
V_CC = 5V
θ_JA = 130°C/W
3.6
10 ^RPROG ^{= 1.69k}
3.5
T_A = 25°C
0
3.4
0 0.25 0.5 0.75 1.0 1.25 1.5 1.75 2.0 2.25
TIME (HOURS)
4054l42 TA01b
4054l42f
1