Thanks for your support. I am now clear, that the variations whatever I had observed, is not due to the Vpulse or Vsource from the analoglib.
I have checked the input.scs file and found all the simulation parameters to be same.
When debugged further, I came to a conclusion, that swapping the voltages given to zero and one values has lead to the variation in the results.
Till now, I felt that whether I swap voltages given to zero and one value, it should not matter. Result should be same.
In order to continue this experiment, I have varied the values given to zero and one in Vpul.
Initially, I had given zero as 0V and one as 100mV. Later I swapped zero and one values and so now, zero is 150mV and one is 0V.
Later, I put zero as 50mV and one as -50mV.
Ideally speaking, the circuit should not work for that voltage. When the input voltage is greater than Vth of the MOS (400mV), circuit will start giving output else output is zero.
I have attached the waveforms associated with it.
Now my question, why is it showing output as ramp down from 95.6mV when zero is 100mV. and one is 0V. Output is ramp up from zero to 350uV, when zero is 0V and one is 100mV. when zero is -50mV and one i s50mV, output is again ramp down from 39mV. I am confused with this behaviour.
I,somehow, feel that output is generated by taking the zero value of the input as an reference value.
Can you please let me know why the behaviour is so?
Awaiting for your reply.
PS: first image in the zip file is when zero value is 50mV and one value is -50mV.
Second image in zip file is when zero is 100mV and one is 0V.
Last is when zero is 0V and one is 100mV