Re: basic querry
nigosawa,
It is true that the base current is a function of Vbe. This is a highly non-linear (exponential) relationship. At the device design level, this relationship is important. At the circuit level, it is more convenient to deal with the Ib/Ic relationship (Ic = Beta*Ib)for two reasons:
1) The relationship is relatively linear for small variations in current
2) Beta is a parameter that is specified
by transistor manufacturers. The Ic/Vbe relationship is not.
Regards,
Kral