MAX1873

• Input-Current Source Limiting
• Charges 4 Lithium-Ion Batteries
• Also Charges Ni-Based Batteries
• Up to 28V Input
• 300kHz PWM Operation
• 16-Pin QSOP Package
• Surface-Mount Construction
• Fully Assembled and Tested

The MAX1873 evaluation kit (EV kit) is a complete, fully assembled and tested PC board that is capable of supplying power to a system load while charging a lithium-ion (Li+) or nickel (Ni)-based battery pack. The EV kit is preset to limit the total source current and the maximum battery-charging current to 3A, and to charge 4-series Li+ cells up to 4.2V each. An analog output voltage proportional to the charging current also permits an ADC or microcontroller to monitor the charging current. The EV kit requires a power source with a minimum output of 18.5V.

The EV kit can be reconfigured to limit the total input current drawn from the power source, the maximum battery-charging current, and the charging cell voltage. The Li+ cell voltage can be set between 4.009V and 4.387V using standard 1% resistors. To charge Li+ battery packs with two or three cells, replace the IC on the EV kit board with one of the ICs listed on the Parts Selection Table.

Applications

• 2-, 3-, or 4-Cell Li+ Battery Pack Chargers
• 6-, 9-, or 10-Cell Li+ Battery Pack Chargers
• Desktop Cradle Chargers
• Handheld Instruments (PDAs, Palmtops)
• Notebook Computers
• Portable Desktop Assistants (PDAs)
• Portable Internet Tablets