Transistor collector current

[samy555]

Hello everyone
We all know that Input Impedance decreased when we choose a high collector current, and that is ok
I want to ask: When one choose high current?
thank you

 

[BurnOut_tesla]

It depend upon ur application..
what load ur driving with the transistor decides the collector current...

 

[LvW]

The transconductance (slope of the VBE-Ic characteristic) is proportional (roughly) to the collector current.

 

[keith1200rs]

Higher current for driving lower impedance loads or for speed.

Keith

 

[LvW]

The transconductance (slope of the VBE-Ic characteristic) is proportional (roughly) to the collector current.

Very often, you can use the simple relationship for (as a result of computing the slope):

transconductance g=h21/h11≈Ic/Ut with Ut≈26mV (temperature voltage).

 

[yangjinhua]

when transistors are used as switch.high collector current may lead transistor to saturation fastly , right ?