above screenshot depicts output configuration in one of STM32 microcontroller. I would like to examine it a bit to understand what is going on and what I can expect.
First of all the manual says we can confugure output as either push-pull or open drain. Couple of questions here:
- If I understand correctly if "Output control" block produces adequate positive voltage then p-mos if off and output pin in n-mos drain - pin pulled to ground. Is it correct?
- How is the above scenario (n-mos active) different then Open drain which for me can only be realized in the same way by n-mos?
- Is there any other adventage of this push-pull configuration then just the possibility of having output pulled to low/high.
- I've been told that in push-pull the current flow is different then it is in case of open drain but I really don't see it. In Push pull current can flow either from Vdd to PIN or from PIN to Vss. In open drain only from PIN to Vss. So it looks like no difference but that person suggested that one configuration allows internal current flow while other external. Does it really?
- I see that PIN is protected by diodes. So if I put higher voltage then Vdd or lower then Vss it will be shorted imediately. Is it correct?
- What is the point of Schmitt trigger for input here?