Q. Show output Characteristic Of Common Emitter Configuration?

Output characteristics: This family of curves may be divided into three regions just as was done for common base configuration. They are active region, saturation region and cut off region. In the active region the collector junction is reverse biased and the emitter junction is forwad biased. The active region is the area right of the ordinate VCE=a few tenths of a volt and above IB=0.In this region the transistor output current responds most sensitively to an input signal.If the transistor is to be used as an amplifying device without appreciable distortion it must be restricted to operate in this region.

The common emitter characteristics in the active region are readily understood qualitatively on the basis of common base configuration. From Kirchoff's current law the base current is

I_B = -(I_C+I_E)

I_C = I_co+α I_IB/1- α

If we define β by

β= I/1-I

I_C= (1+ β) I_co + βI_B