LT1571 Datasheet | Linear Technology

LT1571 Series Constant-Current/ Constant-Voltage Battery Chargers with Preset Voltage and Termination Flag Features s Fast Charging of Li-Ion, Ni MH and Ni Cd Batteries s Simple Charge Current Programming Requires Only One Low Cost, 1/32W Resistor s High Efficiency Charger with Up to 1.5A Charge Current s Precision 0.6% Internal Voltage Reference s Preset Battery Voltages: 4.1V, 4.2V, 8.2V, 8.4V s 500k Hz or 200k Hz Switching Frequency Minimizes Charger Size s Low Reverse Battery Drain Current: 5µA s Flag Indicates Li-Ion Charge pletion s 5% Typical Charge Current Accuracy s Low Shutdown Current s LT1571-1: 200k Hz, Adjustable Voltage LT1571-2: 200k Hz, Fixed 8.2V or 8.4V LT1571-5: 500k Hz, Fixed 4.1V or 4.2V U APPLICATIO S s Cellular Phones, PDAs, Notebook puters, Portable Instruments s Cradle Chargers for Li-Ion, Ni Cd, Ni MH and Lead-Acid Rechargeable Batteries DESCRIPTIO The LT®1571 PWM battery charger is a simple, efficient solution to fast-charge rechargeable batteries including lithium-ion (Li-Ion), nickel-metal-hydride (Ni MH) and nickel-cadmium (Ni Cd) 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. LT1571 can charge batteries ranging from 1V to 20V. A saturating switch operating at 200k Hz (LT1571-1, LT1571-2) or 500k Hz (LT1571-5) gives high efficiency and small charger size. A logic output (flag) indicates Li-Ion near full charge when the charge current drops to 20% of the programmed value. The LT1571-1 and LT1571-2 are in a 28-pin fused lead narrow SSOP power package. The LT1571-5 is in a 16-pin fused lead narrow SSOP power package. , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION VIN 8.2V TO...