If you want 10us or better for a PGOOD signal when the main rail reaches 3.3V*90% (or higher), simply place the main rail on the '+' terminal of a comparator and a VDAC8 set at 3.0V the '-' terminal. PGOOD would be the output of the comparator. It should respond in <0.2us in low power mode.
I thought about it too. But it is more complicated than that because I need to measure more than one voltage (up to 4 at a phase) and I will need 4 VDAC. Where did you see the 0.2us respond?
Regarding the test, I have changed the input clock frequency to 24MHz and filtering to none. The response time was improved to 1ms.
Regarding the example project you have sent me, I I can't open the project files (all but the .cyprj). I am using PSOC creator 2.1
The 0.2us response comes from the datasheet for the comparator:
I'm glad to see that 1ms is better than 10ms. Try adding some averaging to see if the time increases. This is a good test even if it's for educational purposes only.
I created it under Creator 4.2. It is a very stable and full featured version. I recommend this version.
If I understand the back channel discussions, this may be the last release of Creator. Cypress might be enhancing their new tool "ModulusToolBox" to allow for incorporating their other acquired products.