I'm trying to understand why the following circuit, which corresponds to an open collector not gate, needs to use two diodes. The circuit I'm taking about is below:
I think I understand the one just after the Vcc, I guess it's for preventing the current to flow to ground when A is high, am I right? Why can't you just remove the Vcc instead of using that diode?
I'm trying to figure out what is the purpose of the one that is between ground and B, but I don't get why is it necessary to prevent the curent to flow from B to ground.