[SOLVED] Capacitors connected to NMOS- Current and voltage characteristics

[iVenky]

I have attached the circuit. The initial voltages across the capacitors C1 and C2 are +3V and +1V respectively. Ix and Vx are the currents and voltages that I would like to plot with time.
(Note that Vx is the voltage with respect to the ground.)


I tried it using LTSpice and I want to make sure if I am correct.

So could you please tell me the answer.

Thanks in advance.

 

[Milad-D]

The voltage across C2 does not change at all( the current can not flow through it). Therefore the Vgs=1 which means that the transistor always has over drive voltage( assuming that Vth<1).

t=0--> Vx=1+3=4Volts. trnasistor is in saturation and Vx drops linearly till transistor goes to triode Vx=1+2-Vth. After some time Vx reaches 1Volts and stayes constant.