LTC4421 Prioritised PowerPath™ Controller Analog Devices Inc. LTC4421 Prioritised PowerPath™ Controller is designed to drive external N-Channel MOSFETs to connect one of two input supplies to a common output, based on user-defined priority and validity. By definition, the supply connected to V1 is the higher priority supply, although this can be changed dynamically. External resistive dividers set the undervoltage and overvoltage thresholds that bound the valid voltage window.