Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Question about BJT amplifier configuration

Status
Not open for further replies.

hayowazzup

Advanced Member level 4
Joined
Oct 9, 2010
Messages
117
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Activity points
2,136
Hi all,
just wondering if the two bjt configurations work the same?
1. darlington pair
2. common emitter + emitter follower + common emitter
 

KerimF

Advanced Member level 4
Joined
May 17, 2011
Messages
1,461
Helped
374
Reputation
756
Reaction score
370
Trophy points
1,363
Location
Syria
Activity points
12,314
Re: BJT Amplifier config

I am afraid the second configuration is not fully clear. Perhaps it is just me.
 

hayowazzup

Advanced Member level 4
Joined
Oct 9, 2010
Messages
117
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,296
Activity points
2,136
Re: BJT Amplifier config

the second one is amplifiers with a buffer in between
 

KerimF

Advanced Member level 4
Joined
May 17, 2011
Messages
1,461
Helped
374
Reputation
756
Reaction score
370
Trophy points
1,363
Location
Syria
Activity points
12,314
Re: BJT Amplifier config

You mean 3 transistors?... I hope you have a link for its pic.
I am sure, the circuit of interest is simple and clear to you but to those who have seen thousands of circuits, it is hard for them to be 100% sure of all its details from your description.
Sorry... perhaps some others have a better idea of it.
 

LvW

Advanced Member level 5
Joined
May 7, 2008
Messages
5,820
Helped
1,738
Reputation
3,478
Reaction score
1,337
Trophy points
1,393
Location
Germany
Activity points
39,073
Re: BJT Amplifier config

Hi all,
just wondering if the two bjt configurations work the same?
1. darlington pair
2. common emitter + emitter follower + common emitter
The same resp. similar operation? Of course, not.

* The darlington pair works like a single transistor with h21=h21,1*h21,2 but with an overall transconductance g=0.5*g2.
Transconductance g2 (2nd transistor) is determined by Ic,2. (Very often, this is forgotten believing that a high current gain automatically leads to high voltage gain)
* two emitter stages allow more voltage gain. I am not sure if the buffer in between makes really sense.
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top