Monolithic 18V prioritizer provides low standby current backup battery switchover solution

Linear Technology Corporation introduces the LTC4420, a dual input monolithic power prioritizer for 1.8V to 18V systems. To enable portability, preserve memory during brownouts, and ensure a graceful shutdown on power loss, electronic systems employ batteries and capacitors for backup power. The LTC4420 normally powers the load from the higher priority main supply such as a wall adapter or battery, switching to the backup supply—typically a battery or large-value capacitor—during primary brownout or power loss conditions. With up to 18V operating capability, the LTC4420 accommodates a wide range of power sources such as wall adapters, USB ports, supercapacitors, and stacked batteries with Li-Ion, alkaline or NiMH cells. By reducing device operating current to 3.6µA and the backup supply’s standby current drain to a low 0.32µA, the LTC4420 extends run time in portable battery-operated systems.