What is needed to calculate BJT ckts in a design?

[vbhupendra]

BJT ckt Design

What are the parameters do we need to calculate in the design of BJT ckts.
Like in cmos we calculate the W/L dimesions of the transistors. So in BJT what exactly we calculate ?

 

[Chethan]

Re: BJT ckt Design

The parameters u can play around in an BJT is the base n emitter area

 

[pthoppay]

Re: BJT ckt Design

It is totally differnt W/L in MOSFet fixes the DC current for given Vgs. But emitter resistance is one which controls the current (strictly speaking beta, but circuits could be made which are least depend on beta).

So BJT circuit deisgn try to fix Ic by tuning Re.


Regards,
Prakash.

 

[vbhupendra]

Re: BJT ckt Design

Does anyone has the example showing calculation of Base and Emitter area. say we have simple CE amplifier then we have biased it then we calculate beta (if i m not wrong). After this how can we know the base and emitter area.