Darlington Pair/ Darlington Transistor

[Larrytsai]

Hey guys,

I just found out about these darlington transistors, and I read that the purpose of these transistors are to "amplify WEAK signals".

After taking a look at the circuit diagram for the darlington pairs, it seems to me that it is just 2 npn bjts with one of the bjt's emitter connected to the base of the other. Well I was wondering is this how you make a darlington pair?, you just get 2 bjts and connect one emitter to the base of the other?

 

[MisterX]

After taking a look at the circuit diagram for the darlington pairs, it seems to me that it is just 2 npn bjts with one of the bjt's emitter connected to the base of the other. Well I was wondering is this how you make a darlington pair?, you just get 2 bjts and connect one emitter to the base of the other?

No, the transistors should have their collectors connected together as well. It is also possible to have a PNP Darlington pair.

It's worth noting that the http://en.wikipedia.org/wiki/Sziklai_pair" may have advantages over the Darlington Pair.