The LTC4040 adds to the Linear portfolio of battery backup ICs. Batteries are used in backup systems that require longer backup times, as opposed to supercapacitors that are typically used for short-term backup. The LTC4040 performs 3 functions: buck battery charger, boost regulator for backup, and a PowerPath controller to handle the switchover. The device effectively charges both Li-ion and Lithium iron phosphate cells, while its 6.5A internal switch boost backup circuit supports the system load requirements when the input power goes away. The LTC4040 is housed in a low profile 24-pin 4mm x 5mm QFN package.