LTC4007 4A, High Efficiency, Standalone Li-Ion Battery Charger

Product Details

The LTC4007 is a complete constant-current/constant-voltage 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 generate audible noise even when using ceramic capacitors. Charging current is programmable to ±4% accuracy using a programming resistor. Charging current can also be monitored 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 termination 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 condition persists for more than 1/4 of the total charge time.

Applications

  • Notebook Computers
  • Portable Instruments
  • Battery-Backup Systems
  • Standalone Li-Ion Chargers


Features and Benefits

  • Complete Charger Controller for 3- or 4-Cell Lithium-Ion Batteries
  • High Conversion Efficiency: Up to 96%
  • Output Currents Exceeding 4A
  • ±0.8% Charging Voltage Accuracy
  • Built-In Charge Termination for Li-Ion Batteries
  • AC Adapter Current Limiting Maximizes Charge Rate
  • 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, AC Adapter Present, Low Battery, Input Current Limiting and Faults
  • Charging Current Monitor Output
  • Available in a 24-Pin Narrow SSOP Package