LTC4418CUF#PBF

The LTC4418CUF#PBF from Analog Devices is a dual-channel prioritized PowerPath controller that connects one of two valid power supplies to a common output based on priority and validity. Priority is defined by pin assignment: V1 has higher priority, V2 has lower. A supply is valid when its voltage remains within the OV/UV window continuously for at least the configured validation time. The device incorporates fast non-overlap switching circuitry to prevent both reverse and cross conduction while minimizing output voltage droop. The gate driver includes a 6V clamp for external MOSFET protection, and controlled soft-start minimizes inrush current. Multiple LTC4418s can be cascaded for more than two input supplies.

The LTC4418 monitors two input power supplies through external resistive divider networks connected to the UV and OV pins of each channel. When an input voltage remains within its programmed undervoltage/overvoltage window for the duration of the validation time (set by an external capacitor on the TMR pin), the VALID output asserts to indicate a valid supply. The controller always connects the highest-priority valid input (V1) to the common output by driving the gate of the corresponding external P-channel MOSFET. If V1 falls outside its valid window, the V1 channel is immediately disconnected and V2 is connected with minimal switchover time. Fast non-overlap switching ensures both MOSFETs are never on simultaneously, blocking reverse and cross-conduction currents. The 6V gate clamp protects the external MOSFET gates from overvoltage.

• Battery-to-wall-adapter automatic switchover in portable instruments
• Redundant power supply ORing in high-availability servers
• Battery backup systems with priority supply selection
• Industrial systems requiring seamless power path transition
• Automotive dual-battery system prioritization