The MP2639A is a highly integrated, flexible, switch-mode, battery-charging management device for 2-cell series Li-ion and Li-polymer batteries used in a wide range of portable applications. The MP2639A is able to charge a 2-cell battery from a 5V adapter or USB input. The MP2639A can work in three modes: charge mode, discharge mode, and sleep mode. In 2-cell applications, the 5V input charges the 2-cell battery via the MP2639A operating in step-up mode. When the 5V input is absent, the 2-cell battery voltage is discharged to the 5V output via the MP2639A working in step-down mode. It also has cell balance and 4 LED Driver fuel gauge indication. With built in charge current Monitoring in both charge/discharge mode, battery overvoltage protection, and Input Over-Current Protection all inside a 4mmx4mm QFN-26 package this is aimed at portable handheld solutions.