NW72257

NW72257 is a wide input range, high efficiency, synchronous 2-cell series Li-Ion battery cell boost charger. It accepts input from 2.7V to 6V and is capable of delivering up to 2.5A charge current to two stacked Li-Ion batteries. The charging current and termination voltage can both be programmed through external resistors. There are also an input current limit setting and a dynamic input power management setting.

These features can be used for limiting the charging current when a weak power source is plugged in. The boost has a true-shutoff function that disconnects the input from output when short circuit or shut down occurs. A NTC function is also included to configure charging at different temperatures. A STAT function indicates charging status. Furthermore, NW72257 incorporates an OTG function that when enabled, with the same inductor, one can reversely deliver power from the batteries to VBUS. It can deliver up to 2A at 5V.

NW72257 is housed in a tiny QFN3x3-20 package.