Hi my name is kim.
I have a question about mismatch simulation.
I just want to set resistor size by calculating standard deviation.

The attatched file describes my question and hand calculation
I use propagation error formular with assumption that there is no correlation.

Surely, there are no parameter related correlation in model file.

The result in simulation is quiet different with my hand calculation.
Maybe I missed something.

With same sheet resistor, how can I calculate resistor divider mismatch correctly?

Thank you for reading.

R0 and R0+R0 are simulation results.(Monte carlo simulation)
So, R0 and R0+R0 are determined by Ar, W and L.
What I want to know is R0/(R0+R0) standard deviation.
Thanks for reply.

I overlooked that aspect in your hand calculation (One pointed out by Raja). You should have used 2*(20)² instead of 28 in your calculation, but it does not change the outcome significantly as the variance is dominated by the other term (The term that is erroneous is one half of the other).

Hello

Attached is the response to your query. It is exactly same as what Raja commented. Two resistors of equal value have variations which are iid and should be treated as such. That iss where the stddev of the resistor with twice the value, you expressed in your original post becomes irrelevant.