3.4 COMMON-BASE CONFIGURATION
The notation and symbols used in conjunction with the transistor in the majority of
texts and manuals published today are indicated in Fig. 3.6 for the common-base configuration
with pnp and npn transistors. The common-base terminology is derived
from the fact that the base is common to both the input and output sides of the configuration.
In addition, the base is usually the terminal closest to, or at, ground potential.
Throughout this book all current directions will refer to conventional (hole)
flow rather than electron flow. This choice was based primarily on the fact that the
vast amount of literature available at educational and industrial institutions employs
conventional flow and the arrows in all electronic symbols have a direction defined
by this convention. Recall that the arrow in the diode symbol defined the direction of
conduction for conventional current. For the transistor: