LTC4050 Datasheet, PDF (1/12 Pages) Linear Technology – Lithium-Ion Linear Battery Charger with Thermistor Interface

LTC4050
Lithium-Ion Linear Battery
Charger with Thermistor Interface
FEATURES
s _{Complete Standalone Linear Charger Controller}
for 1-Cell Lithium-Ion Batteries
s _{Thermistor Interface for Battery Temperature}
Sensing
s _{Preset Charge Voltage with ±1% Accuracy}
s _{Programmable Charge Current}
s _{C/10 Charge Current Detection Output}
s _{Programmable Charge Termination Timer}
s _{Input Supply (Wall Adapter) Detection Output}
s _{4.5V to 10V Input Voltage Range}
s _{Automatic Sleep Mode When Input Supply}
is Removed (Only 5µA Battery Drain)
s _{Automatic Trickle Charging of Low Voltage Cells}
s _{Automatic Battery Recharge}
s _{Battery Insertion Detection}
s _{Space Saving 10-Pin MSOP Package}
U
APPLICATIO S
s _{Cellular Phones}
s _{Handheld Computers}
s _{Charging Docks and Cradles}
DESCRIPTIO
The LTC^®4050-4.1/LTC4050-4.2 are complete standalone
constant-current/constant-voltage linear charge control-
lers for lithium-ion (Li-Ion) batteries. Charge current is
programmable and final float voltage has ±1% accuracy.
When the input supply is removed, the LTC4050 automati-
cally enters a low quiescent current sleep mode, dropping
the battery drain current to 5µA. An internal comparator
detects the near-end-of-charge (C/10) condition while a
programmable timer, using an external capacitor, sets the
total charge time. Fully discharged cells are automatically
trickle charged at 10% of the programmed current until
cell voltage exceeds 2.49V. The thermistor interface
suspends charging if the cell temperature is outside of a
0°C to 50°C temperature window.
The LTC4050 begins a new charge cycle when a discharged
battery is connected to the charger or when the input power
is applied. In addition, a new charge cycle is automatically
started if the battery remains connected to the charger and
the cell voltage drops below 3.88V for 4.1V cells or below
3.98V for 4.2V cells.
The LTC4050 is available in the 10-pin MSOP package.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
Single Cell 4.2V 500mA Li-Ion Battery Charger
V_IN
6V
MBRM120T3
1k
0.1µF
8
1k
V_CC
9
SENSE
3
CHRG
DRV ⁷
LTC4050-4.2
10
ACPR
1
BAT
4
6
TIMER PROG
*
GND NTC
5
2
19.6k
0.2Ω
1µF
Si9430DY
I_BAT = 500mA
10µF
+ ^4.2V
Li-Ion
CELL
*SHUTDOWN INVOKED BY FLOATING THE PROG PIN
4050 TA01
10k NTC
T _{DALE NTHS-1206N02}
Charge Current vs
Thermistor Temperature
600
V_BAT = 3.7V
500
400
300
200
100
0
–50 –25 0 25 50 75 100 125
THERMISTOR TEMPERATURE (°C)
4050 TA05
4050f
1