LM74700-Q1: Behavior in light load condition

Part Number:LM74700-Q1

Hi Team,

Could you tell me how LM74700 behaves in light load condition?

According to the datasheet, LM74700 controls FET's gate voltage to keep Vds to 20mV fundamentally. But I think it is difficult to keep the 20mV under light load like 100mA with normal power FET.

What kind of issues will come out if we choose 5mohm FET in such the use cass? 

Regards,

Takashi Onawa