The LT1505CG-1 PWM battery charger controller fast charges multiple battery chemistries including lithium-ion (Li-Ion), nickel-metal-hydride (NiMH) and nickel-cadmium (NiCd) using constant-current or constant-voltage control. Maximum current can be easily programmed by resistors or a DAC. The constant-voltage output can be selected for 3 or 4 series Li-Ion cells with 0.5% accuracy.
A third control loop limits the current drawn from the AC adapter during charging*. This allows simultaneous operation of the equipment and fast battery charging without overloading the AC adapter.
The LT1505CG-1 can charge batteries ranging from 2.5V to 20V with dropout voltage as low as 0.5V. Synchronous N-channel FETs switching at 200kHz give high efficiency and allow small inductor size. A diode is not required in series with the battery because the charger automatically enters a 10µA sleep mode when the wall adapter is unplugged. A logic output indicates Li-Ion full charge when current drops to 20% of the programmed value.
The LT1505CG-1 is available in a 28-pin SSOP package.
Feature
- Simple Charging of Li-Ion, NiMH and NiCd Batteries
- Very High Efficiency: Up to 97%
- Precision 0.5% Charging Voltage Accuracy
- Preset Battery Voltages: 12.3V, 12.6V, 16.4V and 16.8V
- 5% Charging Current Accuracy
- Charging Current Programmed by Resistor or DAC
- 0.5V Dropout Voltage, Duty Cycle > 99.5%
- AC Adapter Current Limit* Maximizes Charging Rate
- Flag Indicates Li-Ion Charge Completion
- Auto Shutdown with Adapter Removal
- Only 10µA Battery Drain When Idle
- Synchronizable Up to 280kHz
Applications
- Notebook Computers
- Portable Instruments
- Chargers for Li-Ion, NiMH, NiCd and Lead Acid Rechargeable Batteries
(Picture: Pinout)
