4A, High Efficiency,
Standalone Li-Ion Battery Charger
n Complete Charger Controller for 3- or 4-Cell
n High Conversion Efficiency: Up to 96%
n Output Currents Exceeding 4A
n ±0.8% Charging Voltage Accuracy
n Built-In Charge Termination for Li-Ion Batteries
n AC Adapter Current Limiting Maximizes Charge Rate*
n Thermistor Input for Temperature Qualified Charging
n Wide Input Voltage Range: 6V to 28V
n 0.5V Dropout Voltage; Maximum Duty Cycle: 98%
n Programmable Charge Current: ±4% Accuracy
n Indicator Outputs for Charging, C/10 Current Detection,
AC Adapter Present, Low Battery, Input Current
Limiting and Faults
n Charging Current Monitor Output
n Available in a 24-Pin Narrow SSOP Package
n Notebook Computers
n Portable Instruments
n Battery-Backup Systems
n Standalone Li-Ion Chargers
The LTC®4007 is a complete constant-current/constant-volt-
age charger controller for 3- or 4-cell lithium-ion batteries.
The PWM controller uses a synchronous, quasi-constant
frequency, constant off-time architecture that will not gen-
erate audible noise even when using ceramic capacitors.
Charging current is programmable to ±4% accuracy using
a programming resistor. Charging current can also be mon-
itored as a voltage across the programming resistor.
The output float voltage is pin programmed for cell count
(3 cells or 4 cells) and chemistry (4.2V/4.1V). A timer,
programmed by an external resistor, sets the charge ter-
mination time. Charging is automatically restarted when
cell voltage falls below 3.9V/cell.
LTC4007 includes a thermistor input, which suspends
charging if an unsafe temperature condition is detected.
If the cell voltage is less than 2.5V, a low-battery indicator
asserts and can be used to program a trickle charge current
to safely charge depleted batteries. The FAULT pin is also
asserted and charging terminates if the low-battery con-
dition persists for more than 1/4 of the total charge time.
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trademarks are the property of their respective owners. Protected by U.S. Patents including
12.6V, 4A Li-Ion Battery Charger
0V TO 28V
ICL LTC4007 CLN
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