Summary
Principle summarizes books conductive semiconductor, and a transistor characteristic of the diode.
table of Contents
semiconductor
diode
Transistor
content
semiconductor
Semiconductor (Semiconductor) is a resistivity of the material interposed between the conductors (Conductor) and the insulator (Insulator), substantially IV element.
Silicon lattice (Silicon Lattice)
Since all the electrons are bound in a covalent bond, GU weak conductive silicon. Now added Group V element As, doping atoms have an extra electron is not bound by a covalent bond, the electrons move freely in the crystal lattice, since the electron is defined as negative (Negative), so that the semiconductor is called n-type semiconductor .
If the incorporation group III element, will have a hole, as shown below:
Because the dopant concentration variation, conductive silicon differ by several orders of magnitude, so called a silicon semiconductor.
diode
Constitute the principle diode
The connection between the n-type silicon and p-type silicon diode will be formed (diode), as shown:
The positive electrode (Anode) abbreviated as A, the negative electrode (Cathode, kæθəʊd) abbreviated as K.
Current characteristic of the diode
Only allows current to flow through a one-way, as shown in FIG multisim simulation:
In the left circuit, the current meter reading 0.011A, then we obtain forward bias said diode (Forward bias), forward current (Forward current) through the circuit to the right little circuit is formed at this time is called a diode reverse bias (reverse bias).
Transistor
Transistor (Transistor), the semiconductor device is enlarged or a switch for electrical signals, as follows:
There are three pins, Q1, Q2 representative of the collector (Collector), without reference to the intermediate base (Base), the bottom is the emitter (Emitter), depending on the internal structure of the NPN type and PNP type divided.
DC amplification transistor characteristics
As shown in FIG Transistor BC547A the base and emitter of the transistor such that a voltage 0.7v logic is closed, a current is generated U2 measured, we can say:
1. transistor current gain effect.
2. transistor logic switching effect.
Transistor DC gain
DC gain (dc current gain)
上图U1所测电流Ib 和U2所测电流Ic的比值定义为transistor Q1的直流增益hFE，hFE = Ic / Ib，这里FE分别代表Forward current和Emiiter。
三极管的电流关系式
根据电荷守恒定律和电流的定义可知Iemitter = Ibase + Icollector。
参考文献
[1]《数字设计和计算机体系结构》，第二版，ISBN 978-7-111-53451-8
[2]《电子设计从零开始》，第二版，ISBN 978-7-302-23157-8