DESCRIPTION
The LT ®1571 PWM battery charger is a simple, efficient solution to fast-charge rechargeable batteries including lithium-ion (Li-Ion), nickel-metal-hydride (NiMH) and nickel-cadmium (NiCd) using constant-current and/or constant-voltage control. The internal switch is capable of delivering 1.5A DC current (2A peak current). The onboard current sense resistor (0.1Ω) allows simple charge current programming to within 5% accuracy using a low cost external resistor. The constant-voltage output can be selected for 4.1V or 4.2V per cell with 0.6% accuracy.

FEATURES
■ Fast Charging of Li-Ion, NiMH and NiCd Batteries
■ Simple Charge Current Programming Requires Only One Low Cost, 1/32W Resistor
■ High Efficiency Charger with Up to 1.5A Charge Current
■ Precision 0.6% Internal Voltage Reference
■ Preset Battery Voltages: 4.1V, 4.2V, 8.2V, 8.4V
■ 500kHz or 200kHz Switching Frequency Minimizes Charger Size
■ Low Reverse Battery Drain Current: 5µA
■ Flag Indicates Li-Ion Charge Completion
■ 5% Typical Charge Current Accuracy
■ Low Shutdown Current
■ LT1571-5: 500kHz, Fixed 4.1V or 4.2V LT1571-1: 200kHz, Adjustable Voltage LT1571-2: 200kHz, Fixed 8.2V or 8.4V

APPLICATIONS
■ Cellular Phones, PDAs, Notebook Computers, Portable Instruments
■ Cradle Chargers for Li-Ion, NiCd, NiMH and Lead-Acid Rechargeable Batteries