I am using LTspice to simulate voltage measurements from a circuit. I noticed, with exactly the same circuit components, each time I obtain different results. I assume it is due to thermal noise. (is that right?)
Then I wonder is there a way I can set seed to the SPICE simulation so that my results are reproducible.
To provide more detail: I did a Transient analysis. I am running a circuit with amplifiers, multipliers, resistors and capacitance for 200mS. I run the same circuit with nothing changed (I literally quit LTspice, open again, and hit Run button for the same schema), I found the voltage measurements at one node for the two runs are different. They stay the same for the initial ~30mS, then start to have a lag, then go on completely different tracks. Since nothing about the circuit has changed, I suspect it is caused by thermal noise. Please let me know if there could be other reasons.