文档介绍：Attia, John Okyere. “Transistor Circuits.”
Electronics and Circuit Analysis using MATLAB.
Ed. John Okyere Attia
Boca Raton: CRC Press LLC, 1999
© 1999 by CRC PRESS LLC
CHAPTER TWELVE
TRANSISTOR CIRCUITS
In this chapter, MATLAB will be used to solve problems involving metal-
oxide semiconductor field effect and bipolar junction transistors. The general
topics to be discussed in this chapter are dc model of BJT and MOSFET,
biasing of discrete and integrated circuits, and frequency response of
amplifiers.
BIPOLAR JUNCTION TRANSISTORS
Bipolar junction transistor (BJT) consists of two pn junctions connected back-
to-back. The operation of the BJT depends on the flow of both majority and
minority carriers. There are two types of BJT: npn and pnp transistors. The
electronic symbols of the two types of transistors are shown in Figure .
C I
C IC
B B
I
I B
B I
E E
I C
E
(a) (b)
Figure (a) NPN transistor (b) PNP Transistor
The dc behavior of the BJT can be described by the Ebers-Moll Model. The
equations for the model are
VBE
II= exp− 1()
FES
VT
VBC
II= exp− 1()
RCS
VT
© 1999 CRC Press LLC
and
=−α
IIICFFR ()
=−+α
IIEFRR I ()
and
=−()()αα+−
IIIBFFRR11 ()
where
I ES and I CS are the base-emitter and base-collector saturation
currents, respectively
α
R is large signal reverse current gain of mon-base
configuration
α
F is large signal forward current gain of mon-base
configuration.
and
kT
V = ()
T q
where
k is the Boltzmann’s constant ( k = x 10-23 / o K ),
T is the absolute temperature in degrees Kelvin, and
q is the charge of an