Linear Technology - LTC4420

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.