4057

The 4057 from Abbatron is a versatile linear charger IC specifically engineered for single-cell lithium-ion batteries. It is designed to operate efficiently within USB power specifications, eliminating the need for external sense resistors or blocking diodes due to its internal P-MOSFET architecture. The device offers a programmable charge current, adjustable up to 1.1A, and a preset charge voltage of 4.35V with ±1% accuracy. Thermal feedback regulates the charge current to prevent overheating during high power operation or high ambient temperatures, ensuring safe and reliable charging. The 4057 automatically terminates the charge cycle when the current drops to 1/10th of the programmed value after reaching the final float voltage. When the input supply is removed, it enters a low current state, minimizing battery drain to less than 2µA. The charger can also be put into a shutdown mode, reducing supply current to 55µA. Additional features include battery temperature monitoring, under-voltage lockout, automatic recharge, and status indication pins for charge and termination status. It is available in an ESOP-8 package.

Applications for the 4057 include cellular telephones, mobile power supplies, digital still cameras, MP3 players, Bluetooth devices, portable devices, and USB bus-powered chargers. Its design prioritizes safety and efficiency, making it a robust solution for battery charging in a wide range of portable electronics.