The ap note does not cover stability, or for that matter show f(jw) curves,
so be careful in its use.
A quick test is to feed it with a step and look at response, you can calculate
phase margin from that.
@ Bob - Can you provide a more specific app note - one that is exclusively given for a differentiator ?
@ Dana - thanks. that pdf was awesome. I'd be glad if I get any PSoC specific resources.