# Transistor with multiple collecters and emitters?

Discussion in 'General Electronics Chat' started by samoz, Jun 10, 2009.

1. ### samoz Thread Starter New Member

Jun 10, 2009
7
0
Hi guys, this is my first post here, so bear with me!

I'm trying to design a circuit that takes a 3 bit input to configure its operation. For the purpose of this question, I have 3 signals. say signal A, B, and C that I would like to route around my circuit using transistors. However, depending on which 3 bit input is given, the three signals will all be routed along a set path.

For instance, if the 3 bit input is 101, A goes to pin 1 of a chip, B to pin 2, and C to pin 3. However, if the input is say 010, A would go to 4, B to 5, and C to 6.

I realize that I could do something like this by placing 3 transistors per 3 bit input to route the signals, but I was wondering if there is anything similar to a transistor that has 3 collecters and emitters, but only 1 base? This would save me a lot of hassle (and board space).

Thanks!

P.S. Please don't tell me to reduce the 3 bit input to 2 bits; I know I can configure 3 signals with 2 bits, but I'm using the input signals elsewhere as well, so I need 3 bits.

2. ### beenthere Retired Moderator

Apr 20, 2004
15,815
282
What is the nature of the signals? Are they digital or analog. If analog, what is the signal magnitude? Must signal quality be preserved?

3. ### samoz Thread Starter New Member

Jun 10, 2009
7
0
They are digital, a simple 0 or 1. They will be specified by whether or not a jumper is set when the circuit has power applied to it.

4. ### hobbyist Distinguished Member

Aug 10, 2008
764
56
If the inputs are parrallel then wouldn't you need 3 base's (input terminals) to rout the signals to there appropriate emitter, collector, junctions?

5. ### beenthere Retired Moderator

Apr 20, 2004
15,815
282
Sounds like a multiplexer will do what you want. The type depends on the logic (TTL or CMOS) being used.