I am attempting to do a Monte Carlo simulation of a basic current measurement circuit using SiMetrix. The current goes through a sense resistor, amplified by an op-amp and then to an ADC. I'm trying to include the error of the ADC in my simulation, but I can't figure out how to randomize it. I found that the total error contribution of the ADC is +/- 5mV. How can I add that error to the output of my op-amp for use in a Monte Carlo simulation? I would like to make it a Gaussian distribution, similar to what you do with resistor tolerances. The problem with gauss is that it is a multiplier, and therefore would not give me any results centered about 0 (0 * multiplier = 0). Here is the sim schematic:
Option 1: Sine wave voltage source in series with output
This option will add or subtract 5mV from the output signal in a transient analysis, but it is not random.
Option 2: Current source in parallel with a resistor with gauss tolerance
This option would give me the distribution I want, but I don't know how to get the current to randomly switch directions or magnitude (to give me +/- 5mV max).
Option 3: DC voltage source in series with the output
This option would give me a static 5mV offset, but this is not useful in Monte Carlo sims.
Option 4: Noise source?
Could a noise source accomplish this random behavior? I was ultimately trying to get a gauss distribution, but I would be happy with pseudo-random.
Option 5: Voltage controlled voltage source
I could use a voltage controlled voltage source with a gain set to 1 and some distribution about 1. The problem with this method is that it would have less effect at lower voltages since it is ratiometric.