![]() The reasons for this have to do with obscure details of semiconductor theory, which I’d rather not discuss in this chapter. Generally, N-channel JFETs are more commonly used than P-channel. P-type channel JFETs are also manufactured: In the image just shown, this channel is an N-type semiconductor. Note how the current does not have to cross through a PN junction on its way between source and drain: the path (called a channel) is an uninterrupted block of semiconductor material. The controlling voltage is applied between the gate and source. In a junction field-effect transistor or JFET, the controlled current passes from source to drain, or from drain to source as the case may be. This becomes more evident when a physical diagram of the device is seen: That is, the main current through them is comprised either of electrons through an N-type semiconductor or holes through a P-type semiconductor. In the next chapter, we’ll explore another type of field-effect transistor, the insulated gate variety.Īll field-effect transistors are unipolar rather than bipolar devices. In this chapter, we’ll introduce the general concept of the field-effect transistor-a device utilizing a small voltage to control current-and then focus on one particular type: the junction field-effect transistor. In the last chapter, we studied bipolar transistors, which utilize a small current to control a large current. Transistors may be roughly grouped into two major divisions: bipolar and field-effect. \)Ī transistor is a linear semiconductor device that controls current with the application of a lower-power electrical signal.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |