The LA5621M and LA5621V are external charge control ICs for lithium-ion batteries. These ICs are ideally suited for on/off control of external power MOSFETs in systems that incorporate a charging circuit in the set. They detect the charge and discharge status, output it to the set control microcontroller, which then outputs a signal to switch external power MOSFETS either on or off. Moreover, these ICs have a built-in function that detects discharge (countercurrent) from lithium-ion batteries within sets to external lithium-ion batteries in an AC adapter/charger, etc. and switches external power MOSFETs off.