Automotive ORing controller with AEC-Q100 grade-1 temperature range
The LM74700QDDFRQ1 is a Texas Instruments N+1 ORing controller designed for redundant supply architectures in automotive electronics. The controller drives an external N-channel MOSFET (no internal switch) and manages the ORing function with a 1.4 µs ON delay and 450 ns OFF delay. The fast OFF delay is critical: when the active supply drops, the controller shuts the FET in under half a microsecond to prevent reverse-current backfeed into the failed rail.
3.2V–65V supply range — covers 12V, 24V, and 48V automotive buses
The supply voltage range of 3.2V to 65V covers the nominal 12V/24V/48V automotive rails plus load-dump transients up to 60V. The 5A maximum output current drives the gate of the external N-channel MOSFET hard enough to achieve the 1.4 µs turn-on time even with a large die FET. The 1:1 input-to-output ratio means each ORing channel passes one supply rail; in an N+1 configuration, multiple controllers share a common output bus. The SOT-23-8 (TSOT-23-8) package keeps the PCB footprint small — critical when packing redundant power paths into a compact ECU.