Hello,
I have a driver circuit driving a Power n-mosfet, If I dont connect any load at source of Mosfet what would be the voltage at Vout when my input is low?

 

What is Vin relative to VDD?

 

Vin Would be basically a Pwm Input signal with voltage levels at 0-4V. The Driver Output driving the Mos would have a voltage level varrying from 0 to 2VDD.

 

If the driver is of the bootstrap type, which relies on the source being periodically grounded to provide a boosted gate voltage for high-side switching of a load, then it won't generate 2x Vdd, the FET won't turn on and with no load the source will probably drift up to Vdd through leakage.