The gate driver is used to control the external N-Channel MOSFET by setting the appropriate GATE to SRC voltage.

Before the gate driver is enabled following three conditions must be achieved:

• The EN/UVLO pin voltage must be greater than the specified input high voltage.
• The VCAP to VS voltage must be greater than the undervoltage lockout voltage.
• The VS voltage must be greater than V_S POR Rising threshold.

The controller offers two gate drive variants. LM74502-Q1 with typical peak gate drive strength of 60 μA is suitable to achieve smooth start-up with inherent inrush current control due to its lower gate drive strength.

LM74502H-Q1 with its 11-mA typical peak gate drive strength is suitable for applications which need faster turn-on such as load switch applications.

LM74502-Q1, LM74502H-Q1 SRC pin is capable of handling negative voltage which also makes it suitable for load disconnect switch applications with loads which are inductive in nature.