LTC4006_15 Datasheet, PDF (1/20 Pages) Linear Technology – 4A, High Efficiency, Standalone Li-Ion Battery Charger

LTC4006
4A, High Efficiency,
Standalone Li-Ion
Battery Charger
FEATURES
DESCRIPTIO
■ _{Complete Charger Controller for 2-, 3- or 4-Cell}
Lithium-Ion Batteries
■ _{High Conversion Efficiency: Up to 96%}
■ _{Output Currents Exceeding 4A}
■ _{±0.8% Accurate Preset Voltages: 8.4V, 12.6V, 16.8V}
■ _{Built-In Charge Termination with Automatic Restart}
■ _{AC Adapter Current Limiting Maximizes Charge Rate*}
■ _{Automatic Conditioning of Deeply Discharged}
Batteries
■ _{Thermistor Input for Temperature Qualified Charging}
■ _{Wide Input Voltage Range: 6V to 28V}
■ _{0.5V Dropout Voltage; Maximum Duty Cycle: 98%}
■ _{Programmable Charge Current: ±4% Accuracy}
■ _{Indicator Outputs for Charging, C/10 Current}
Detection and AC Adapter Present
■ _{Charging Current Monitor Output}
■ _{16-Pin Narrow SSOP Package}
U
APPLICATIO S
■ _{Notebook Computers}
■ _{Portable Instruments}
■ _{Battery-Backup Systems}
■ _{Standalone Li-Ion Chargers}
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% voltage accuracy. Charging current is program-
mable with a single sense resistor to ±4% typical accuracy.
Charging 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. Charg-
ing automatically resumes when the 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.
The LTC4006 includes a thermistor sensor input that
suspends charging if an unsafe temperature condition is
detected and automatically resumes charging when the
battery temperature returns to within safe limits.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents
including 5723970.
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
TO SYSTEM LOAD
20µF
10µH
0.025Ω
BATTERY
20µF
4006 TA01
4006fa
1