The analog device LTC4421 prioritizes a PowerPath controller to drive an external N-channel MOSFET to one of two input supplies, to a common output based on user-defined priority and availability. By definition, a power supply connected to V1 is a higher priority power supply, although it can be modified dynamically. The external resistor divider fixedly limits the undervoltage and overvoltage thresholds of the effective voltage window.
Powerful gate driver for fast switching of external N-channel MOSFETs. A fast switching circuit stops reverse and cross conduction while switching channels, minimizing output drops. The fast comparator recognizes a shorted input and quickly turns off the N-channel MOSFET to reduce interference.
The external sense resistor sets the maximum inrush current and current limit current. With current limiting, the device controls the gate of the N-channel MOSFET to regulate a 25mV voltage across the sense resistor. When the sense resistor voltage is adjusted to 25mV within the time set by the user, the channel is disconnected and the fault is set.
Typical applications include high-reliability systems, server-based backup systems, industrial handheld instruments, and battery backup systems.