The MAX1879 single-cell lithium-ion (Li+) battery charger utilizes an efficient pulse-charging architecture to minimize power dissipation in portable devices. This architecture combines the efficiency of switch-mode chargers with the simplicity and low cost of linear chargers. This simple device, in conjunction with a current-limited wall cube and a PMOS transistor, allows safe and fast charging of a single Li+ cell.

The MAX1879 initiates charging in one of three ways: battery insertion, charger power-up, or toggling the THERM pin. Key safety features include continuous voltage and temperature monitoring, a preset charger time-out, and an 8mA precharge current mode to charge near-dead cells. Automatic detection of input power removal shuts down the device, minimizing current drain from the battery. An overall system accuracy of 0.75% ensures that the cell capacity is fully utilized without cycle life degradation.

The MAX1879 is offered in a space-saving 8-pin µMAX® package. An evaluation kit (MAX1879EVKIT) is available to help reduce design time.

Applications

• Cell Phones
• Consumer Audio
• Cordless Phones
• Digital Still Cameras
• Global Positioning Systems (GPS)
• Pagers
• Palmtops, Handy Terminals
• Pen Entry Palmtops, PDAs and Organizers
• Smart Battery Packs/Chargers