The LTC4007EUFD-1 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.
LTC4007EUFD-1 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.
LTC4007LTC4007-1Low battery threshold 4.2V cell2.5V3.25VLow battery threshold 4.1V cell2.44V3.173VRestartEnabledDisabledPackageSSOP-24QFN-24Feature
- 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
Applications
- Notebook Computers
- Portable Instruments
- Battery-Backup Systems
- Standalone Li-Ion Chargers
