Velleman DCA75 - Manual (Page 16)

Atlas DCA Pro User Guide December 2012 – Rev 1
Page 16
VBE=0.703V
at IB=5.00mA
Base-Emitter Voltage Drop
The DC characteristics of the base-emitter
junction are displayed, both the base-emitter
forward voltage drop (V
BE
) and the base
current (I
B
) used for the measurement.
This example shows an NPN base-
emitter voltage (V
BE
) of 0.703V for a
base test current (I
B
) of 5mA.
The forward base-emitter voltage drop can aid in the identification of silicon or
germanium devices. Germanium devices can have base-emitter voltages as low
as 0.2V, Silicon types exhibit readings of about 0.7V and Darlington transistors
can exhibit readings of about 1.2V because of the multiple base-emitter
junctions being measured.
It is important to note that the DCA Pro does not perform the base-
emitter voltage drop tests at the same base current as that used for the
current gain measurement. V
BE
is measured at a base current of
approximately 5mA. The base current used during the gain
measurement is equal to I
C
/H
FE
.
IB
VBE