Linear Technology's LTC4417 connects one of three valid power supplies to a common output based on priority. Priority is defined by pin assignment, with V1 assigned the highest priority and V3 the lowest priority. A power supply is defined as valid when its voltage has been within its overvoltage (OV) and undervoltage (UV) window continuously for at least 256 ms. If the highest priority valid input falls out of the OV/UV window, the channel is immediately disconnected and the next highest priority valid input is connected to the common output. Two or more LTC4417s can be cascaded to provide switchover between more than three inputs.

The LTC4417 incorporates fast non-overlap switching circuitry to prevent both reverse and cross conduction while minimizing output droop. The gate driver includes a 6 V clamp to protect external MOSFETs. A controlled output ramp feature minimizes start-up inrush current. Open drain VALID outputs indicate the input supplies have been within their OV/UV window for 256 ms.

Video: Prioritized PowerPath Controllers