A, C, GATE comprises of ideal diode stage. Connect the Source of the external MOSFET to A, Drain to C and Gate to GATE pin. The LM74721-Q1 has integrated reverse input protection down to –33 V.

In LM74721-Q1 the voltage drop across the MOSFET is continuously monitored between the A and C pins, and the GATE to A voltage is adjusted as needed to regulate the forward voltage drop at 17 mV (typical) for LM74721-Q1. This closed loop regulation scheme enables graceful turn-off of the MOSFET during a reverse current event and ensures zero DC reverse current flow. This scheme ensures robust performance during slow input voltage ramp down tests. Along with the linear regulation amplifier scheme, the LM74721-Q1 also integrates a fast reverse voltage comparator. When the voltage drop across A and C reaches V_{(AC_REV)} threshold, then the GATE goes low within 0.5 µs (typical). This fast reverse voltage comparator scheme ensures robust performance during fast input voltage ramp down tests such as input micro-shorts. The external MOSFET is turned ON back when the voltage across A and C hits V_{(AC_FWD)} threshold within 1.9 µs (typical) for LM74721-Q1. For ideal diode only designs, connect LM74721-Q1 as shown in Figure 8-1

Figure 8-1 Configuring LM74721-Q1 for Ideal Diode Only