LTC4050
Lithium-Ion Linear Battery
Charger with Thermistor Interface
FEATURES
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DESCRIPTIO
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Complete Standalone Linear Charger Controller
for 1-Cell Lithium-Ion Batteries
Thermistor Interface for Battery Temperature
Sensing
Preset Charge Voltage with
鹵1%
Accuracy
Programmable Charge Current
C/10 Charge Current Detection Output
Programmable Charge Termination Timer
Input Supply (Wall Adapter) Detection Output
4.5V to 10V Input Voltage Range
Automatic Sleep Mode When Input Supply
is Removed (Only 5碌A(chǔ) Battery Drain)
Automatic Trickle Charging of Low Voltage Cells
Automatic Battery Recharge
Battery Insertion Detection
Space Saving 10-Pin MSOP Package
The LTC
廬
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
鹵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 5碌A(chǔ). 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擄C to 50擄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.
APPLICATIO S
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Cellular Phones
Handheld Computers
Charging Docks and Cradles
TYPICAL APPLICATIO
Single Cell 4.2V 500mA Li-Ion Battery Charger
V
IN
6V
MBRM120T3
8
1k
1k
3
CHRG
V
CC
SENSE
DRV
0.2鈩?/div>
9
7
Si9430DY
I
BAT
= 500mA
*
19.6k
10碌F
1碌F
600
V
BAT
= 3.7V
500
CHARGE CURRENT (mA)
400
300
200
100
LTC4050-4.2
10
4
0.1碌F
ACPR
TIMER
GND
5
BAT
PROG
NTC
2
1
6
+
4.2V
Li-Ion
CELL
10k NTC
T DALE NTHS-1206N02
*SHUTDOWN INVOKED BY FLOATING THE PROG PIN
4050 TA01
U
Charge Current vs
Thermistor Temperature
0
50
100
鈥?0 鈥?5
25
75
0
THERMISTOR TEMPERATURE (擄C)
125
4050 TA05
U
U
4050f
1
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