Hi there..
I'm trying to bias a transistor KTC3198 with respect to its output and input characteristics. So my question is: since I'm after the highest dc current gain the transistor can deliver at the output, is okay to place the q point a bit higher than the usual middle part of the output charesteristics ?

MOD NOTE: Link removed. Your link, presumably to the transistor data sheet, was meaningless garbage.

 

Welcome to AAC!

It's generally considered unwise to design for more than the minimum transistor beta.

Could you post a schematic so we can understand why you want to design for something other than the minimum guaranteed beta?

Your link was blocked by my browser.

 

Here's a KTC3198 datasheet that I tracked down at DigiKey for you.

 

Hi there..
I'm trying to bias a transistor KTC3198 with respect to its output and input characteristics. So my question is: since I'm after the highest dc current gain the transistor can deliver at the output, is okay to place the q point a bit higher than the usual middle part of the output charesteristics ?

You need to provide more detail about exactly what you are proposing.

For a given transistor and all else being held constant, the DC current gain generally goes down with collector current.



But it also goes up with temperature, so having more current MIGHT result in a net increase in gain if the additional dissipation heats the transistor.

But both of these can be completely swamped by the variation from one transistor to another, so your design should be based on being able to work for ANY DC current gain that the specs allow it to have.

Also, notice that this particular transistor is binned by the manufacturer into four different device codes based on h_FE. So choosing a higher-h_FE device code will get you higher DC current gains than any games you might play with a lower-h_FE device code.