Main Question or Discussion Point
Just wondering how would one design a comparator using just discrete BJTs.
To make a discrete differential pair, you will usually use a matched transistor pair. There is too much mismatch/offset when you use separate transistors, especially over temperature:Emitter coupled pair like the one in attachment?
I've been playing with this since yesterday. How do you fix the gain of this ckt.
In the ckt, how do I overcome the min Vbe requirement of Q1,Q2.
For a TTL output comparator a BJT configured as a CE amplifier with Vcc=5v would work?
I just need something that works and also simple enough to understand.
Ok I modified your circuit to make about the simplest "comparator" possible out of a few discrete components.huh. Here it is.