I need to design a two-stage comparator using only bjts.

[mastevano]

Does anyone have sample schematics or any ideas on how to start this?

 

[papyaki]

Hi,

Dont know if it is what you want, but your requirement looks like the old schmitt trigger.

Look there :

h**p://www.visionics.ee/curriculum/Experiments/Schmitt%20Trigger/Schmitt%20Trigger1.html

replace * whith when copying the link

 

[mastevano]

Thanks. That is helpful. I looked into my requirements a little more and realized that it is supposed to be designed as an op-amp.