[SOLVED] Can a MOSFET amplify DC?

[cannibol_90]

Can a MOSFET amplify DC without the help of any resistor? For example, I give an input of 1V DC and the output is needed to be 2V DC (any DC biasing voltage). How can I achieve this?

 

[Audioguru]

A Mosfet inverts the input voltage if the input voltage is high enough to turn on the Mosfet. For an N-channel Mosfet a positive going input at the gate causes an output voltage at the drain to drop.
Many Mosfets have a threshold voltage (voltage from gate to source) of 2V to 4V for it to conduct (drain current) only 0.25mA. It has a transconductance (input voltage change causing output current change) that is low for one Mosfet or fairly high for another Mosfet even if they have the same part number. The average transconductance is high so with plenty of negative feedback you can have a voltage gain of 2.0 if the circuit is designed correctly.

 

[D.A.(Tony)Stewart]

You can get an inverting gain up to 50 or more with one stage. but not a DC gain of two for 0~1 to 0~2.

That would require 2 inverting stages and suitable Vdd, Vss with feedback ratio to control gain and perhaps requirements for Zout, Gain and offset.