The AT73C203 device provides an integrated solution to portable and handheld applications built around microprocessors requiring "smart" power management functions, such as PDAs, Palmtop computers, point-of-sales terminals, 3G modems, etc. Its compact package outline and small size of external components make the AT73C203 suitable for PCMCIA card power management as well. The AT73C203 integrates a power switch controller that, when connected to an external power switch, may be used for automatically selecting one of four possible power sources: