A, C, DGATE comprises of Ideal Diode stage. Connect the Source of the external MOSFET to A, Drain to C and Gate to DGATE. The LM74930-Q1 has integrated input reverse polarity protection down to –65 V.

Before the DGATE driver is enabled, following conditions must be achieved:

• The EN pin voltage must be greater than the specified input high voltage.
• The CAP to VS voltage must be greater than the undervoltage lockout voltage.
• Voltage at A pin must be greater than VA POR Rising threshold.
• Voltage at VS pin must be greater than VS POR Rising threshold.

If the above conditions are not achieved, then the DGATE pin is internally connected to the A pin, assuring that the external MOSFET is disabled.

In LM74930-Q1 the voltage drop across the MOSFET is continuously monitored between the A and C pins, and the DGATE to A voltage is adjusted as needed to regulate the forward voltage drop at 10.5 mV (typ). 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 LM74930-Q1 also integrates a fast reverse voltage comparator. When the voltage drop across A and C reaches V_{(AC_REV)} threshold then the DGATE goes low within 0.5-µs (typ). 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 2.8 µs (typ).