LTC4006 Datasheet, PDF (1/16 Pages) Linear Technology – 4A, High Efficiency, Standalone Li-Ion Battery Charger

Final Electrical Specifications
LTC4006
4A, High Efficiency,
Standalone Li-Ion Battery Charger
May 2003
FEATURES
DESCRIPTIO
s _{Complete Charger Controller for 2-, 3- or 4-Cell}
Lithium-Ion Batteries
s _{High Conversion Efficiency: Up to 96%}
s _{Output Currents Exceeding 4A}
s _{±0.8% Accurate Preset Voltages: 8.4V, 12.6V, 16.8V}
s _{Built-In Charge Termination with Automatic Restart}
s _{AC Adapter Current Limiting Maximizes Charge Rate*}
s _{Automatic Conditioning of Deeply Discharged}
Batteries
s _{Thermistor Input for Temperature Qualified Charging}
s _{Wide Input Voltage Range: 6V to 28V}
s _{0.5V Dropout Voltage; Maximum Duty Cycle: 98%}
s _{Programmable Charge Current: ±5% Accuracy}
s _{Indicator Outputs for Charging, C/10 Current}
Detection and AC Adapter Present
s _{Charging Current Monitor Output}
s _{16-Pin Narrow SSOP Package}
U
APPLICATIO S
The LTC^®4006 is a complete constant-current/constant-
voltage charger controller for 2-, 3- or 4-cell lithium bat-
teries in a small package using few external components.
The PWM controller is a synchronous, quasi-constant fre-
quency, constant off-time architecture that will not gener-
ate audible noise even when using ceramic capacitors.
The LTC4006 is available in 8.4V, 12.6V and 16.8V versions
with ±0.8% accuracy. Charging current is programmable
with a single sense resistor to ±4% typical accuracy. Charg-
ing current can be monitored as a representative voltage at
the I_MON pin. A timer, programmed by an external resistor,
sets the total charge time or is reset to 25% of total charge
time after C/10 charging current is reached. Charging au-
tomatically resumes when cell voltage falls below 3.9V/cell.
Fully discharged cells are automatically trickle charged at
10% of the programmed current until the cell voltage ex-
ceeds 2.5V/cell. Charging terminates if the low-battery
condition persists for more than 25% of the total charge
time.
s _{Notebook Computers}
s _{Portable Instruments}
s _{Battery-Backup Systems}
s _{Standalone Li-Ion Chargers}
LTC4006 includes a thermistor sensor input that sus-
pends charging if an unsafe temperature condition is
detected and automatically resumes charging when bat-
tery temperature returns to within safe limits.
, LTC and LT are registered trademarks of Linear Technology Corporation.
*U.S. Patent No. 5,723,970
TYPICAL APPLICATIO
4A Li-Ion Battery Charger
DCIN
0V TO 28V
3A
V_LOGIC
CHG
ACP
CHARGING
CURRENT MONITOR
0.1µF
100k
32.4k
THERMISTOR
10k
NTC
0.0047µF
309k
TIMING
6k
0.47µF ^RESISTOR
(~2 HOURS) _0.12µF
INPUT SWITCH
DCIN
INFET
LTC4006
CHG
CLP
ACP/SHDN CLN
I_MON
NTC
TGATE
BGATE
R_T
PGND
I_TH
CSP
GND
BAT
5k
15nF 0.033Ω
20µF
10µH
0.025Ω
BATTERY
20µF
4006 TA01
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
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