BD4201FV is a battery backup IC. Switch that detect battery voltage and switch into back up power supply and 3-channel regulator are incorporated into a single chip. Current consumption is 15µA (Max.). This IC is perfect for portable appliances.

zFeatures
1) Low quiescent current Normal operation < 15.0µA Max. Backup mode < 2.1µA Max.
2) 3 high accurate voltage regulators
3) Low dropout voltage, and high accurate voltage detectors (CS, RESET)
4) Control circuit; Backup
5) Special sequence; For shifting to the backup mode. It need to make main battery over +Vdet1 once.

Applications
    Portable video, Digital camera