In the simulation, i can simply change an enhancement mode nmos into a depletion mode nmos by adding an offset voltage at the gate. But in the real lab, if i do not have the depletion mode nmos. How can i combime or add something at the gate to make a depletion nmos from enhancement nmos. Since, it might be hard to always keep an offset voltage at the gate. I am just wondering if there is a substitute of the offset voltage. Thanks for your guidance!

 

From what I remember, the enhancement mode mosfet is a normally open switch and hence we need gate voltage to turn it on and depletion mode mosfet is a normally closed switch and would require gate voltage to turn it off.

So maybe use it as a PMOS in the digital design parts and I have no idea as to what you can do for analog design. I could be wrong, but experiment a bit maybe

 

I am just wondering if there is a substitute of the offset voltage.

Unfortunately not.
In common-drain mode, if you want the device to switch fully on, you will need to take the gate voltage above the positive supply.

 

Unfortunately not.
In common-drain mode, if you want the device to switch fully on, you will need to take the gate voltage above the positive supply.

Which you can do with a boostrap circuit

 

Which you can do with a boostrap circuit

But not at high mark-space ratios, or DC.

 

But not at high mark-space ratios, or DC.

There is something about every circuit configuration that sucks.