Stable 200uA Current source by cascading REF200's Current source and Current mirror
I think you're not using the REF200 correctly:

You connect the two 100 uA current sources in series, current sources in series is a big NO-NO in electronics (unless you don't care about the actual currents).

Suppose one current source wants 100.00 uA to flow but the other one wants 100.05 uA to flow, what will the current be? (the 100.00 uA source will usually win but that is besides the point). Just don't connect current sources in series. To sum (add up) the currents, just connect the current sources in parallel.

The way you use the current mirror is at least a bit odd as you take the output current from the mirror common. Not impossible if you take care that the mirror can work (has the right voltages etc.) just a bit odd.

To make the 200 uA you need, you can also just connect the two current sources in parallel.

I do not (yet) see a way how to make the one 100uA (I) and a 200 uA (2I) from one REF200. I think you need two of them:


use one current source for the 100 uA
use two current sources in parallel for the 200 uA
do not use the current mirrors at all