1 三极管的结构和分类（Structure and classification of 1 transistor）.docVIP

1 三极管的结构和分类（Structure and classification of 1 transistor） The 1 transistor structure and classification The common feature that has three electrodes, which is referred to as triode. Popular speaking, the internal transistor is composed of three layer structure of P type semiconductor and N type semiconductor components, according to the hierarchical order is divided into NPN type and PNP type two categories. The three layer structure is three area transistor, the middle is a thin layer of base area, the other two layers with N type or P type, the size is relatively small, the majority carrier concentration relatively high for a launch area, another layer is the collector region. The internal structure characteristics of transistor, the transistor is can enlarge the role of internal conditions. Three each area leads to the three electrodes, respectively (b), base emitter and collector (E) (C). As shown in Figure B, three layer structure can form two PN junction, called the emitter and collector junction. The direction of the arrow symbol in the triode emitter direction is said. The two transistor has a one-way conductive PN junction internal structure, therefore it can certainly be used as a switching element, but at the same time or a triode amplifying element, it is the emergence of a leap in the development of electronic technology. The 2 transistor current amplification effect DC voltage source Vcc should be greater than Vbb, so that the circuit meets the amplification of the external conditions: emitter junction forward bias collector reverse bias. Change the adjustable resistor Rb, base current IB, collector current Ic and emitter current IE will change, from the results, the following conclusions can be drawn: (1) IE = IB + IC (in line with the current J F Herve theorem) (2) IC = IB (x?? called the current amplification factor, which can characterize the transistor current amplification ability) (3) IC = IB * *? From the above, a transistor is a simulator with