Semiconductor transistor
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Semiconductor transistor
It is a semiconductor device that internally contains two PN junctions, usually with three extraction electrodes on the outside. It has the functions of amplification and switching of electric signals, and is widely used. Both the input stage and the output stage use a transistor logic circuit called a transistor-transistor logic circuit. In books and practical applications, it is simply referred to as a TTL circuit. It is a type of semiconductor integrated circuit, and the most common one is TTL NAND gate. TTL NAND gates are a system of several transistors and resistors that are fabricated on a small piece of silicon and packaged into a single component. Semiconductor triodes are one of the most widely used devices in circuits, and are represented by "V" or "VT" (the old text symbols are "Q", "GB", etc.) in the circuit.
Semiconductor triodes fall into two main categories: bipolar transistors (BJT) and field effect transistors (FETs). The transistor has three poles; the three poles of the bipolar transistor are composed of an N-type and a P-type emitter (Emitter), a base (Base) and a collector (Collector); the three poles of the field effect transistor are respectively Source, Gate, and Drain. Because there are three kinds of polarities, there are three ways to use them: emitter grounding (also known as common-emitter amplification, CE configuration), base grounding, and collector grounding. The most common use should be in the aspect of signal amplification, followed by impedance matching, signal conversion, etc. Transistors are an important component in the circuit. Many precision components are mainly made of transistors.
Whether the triode's conducting transistor is in the amplified state or the switching state depends on the DC bias applied to the base of the triode. With this current change, the triode operating state is changed by the off-linear region-saturation state, if the triode Ib (DC bias) At a certain time, the triode works in the linear region. At this time, the change of Ic current only changes with the AC signal of Ib, Ib continues to rise, and the triode enters saturation state. At this time, the Ic of the triode does not change, and the triode will work in the switch. status.
When the triode is used as a switching tube, it operates in a saturated state 1, and it is not very scientific to use the amplification state 1.
Please refer to my answer in the Ib;Ic curve of the triode manual to understand the working state of the triode, and the triode be and ce junction triode can work normally.
If the triode is not biased with DC, when the AC sinusoidal signal input during the amplifying circuit is half a week, the base is positive to the emitter. Since the emitter is applied with a reverse voltage, there is no base current and collector. Current, at this time, the collector current changes and the base is inverted. At the negative half of the input voltage, the emitter potential is positive for the base potential. At this time, since the emitter is applied with a forward voltage, the base and collector are available. When the current passes, the collector current changes in phase with the base. When the triode is not DC biased, the triode be and ce junctions are turned on. The triode amplifier circuit will only have half of the wave output and will produce severe