What is the function of a transistor? What is the function of a transistor?

Choose Huaxin Optoelectronics, the company's product range mainly covers LED lighting, LED lighting, LED lights, LED backlight drivers, smart homes, LED displays, etc., our company launched a driver-free dimmable constant current driver IC, high efficiency, high PFC, widely used in integrated photoelectric modules, COB products, improve the reliability of LED lighting products, improve the production efficiency of products, and provide a core solution for solid-state lighting.

The transistor must have certain external conditions to amplify the signal, that is, to add a forward voltage to the transmitting junction of the transistor (customarily called forward bias or forward bias), and a reverse voltage to the collector junction (commonly known as reverse bias or reverse bias). The main applications of transistors are divided into two aspects. First, it works in saturation and cut-off states and is used as a transistor switch; The second is to work in an amplified state and be used as an amplifier.

Amplification area: At this time, IC= 0 8IB, IC basically does not change with the change of UCE, at this time, the transmitting junction is positively biased, and the collector junction is reversed. Amplification Status:

UB 0, transmit junction positive bias, collector junction reverse bias, ic= ib.

One-way energizing, some things can't use alternating current, the diode reverse resistance is very large, and the forward direction is very small, which plays such a role.

The transistor can amplify the current or voltage. Current amplification = ice ibe=(ic-icbo) (ibe-icbo) ic ib, voltage amplification au=uo ui.

1. The current amplification of the transistor is also known as the current distribution coefficient of the transistor, and the letter is a Greek letter.

The current amplification factor is the ratio of the number of electrons drifting to the collector region or their change to the number of electrons recombined in the base region or their change, that is, the ratio of ICE to IBE. Denoted by . β=ice/ibe=(ic-icbo)/(ibe-icbo)≈ic/ib

2. The voltage amplification factor refers to the ratio of the output voltage of the amplifier circuit to the input voltage. If it is set to sinusoidal input and output, UI is the input voltage, and UO is the output voltage, then the voltage amplification factor AU=UO UI.

Extended Information: Transistor Amplification Principle:

1. The launch zone emits electrons to the base zone.

The power supply UB is added to the emission junction through the resistor RB, and the emission junction is positively biased, and most of the carriers (free electrons) in the emission region continuously cross the emission junction into the base region, forming the emitter current IE. At the same time, most of the carriers in the base region also diffuse to the emission region, but since the concentration of most carriers is much lower than the concentration of carriers in the emission region, this current can be disregarded, so it can be considered that the emission junction is mainly an electron flow.

2. Diffusion and recombination of electrons in the base region.

After the electrons enter the base region, they are first densely packed near the emission junction, and gradually form an electron concentration difference, which promotes the electron flow to diffuse to the collector junction in the base region, and is pulled into the collector region by the collector electric field to form a collector current IC. There is also a small fraction of electrons (because the base region is very thin) that reunites with the holes in the base region, and the ratio of the diffusion electron flow to the composite electron flow determines the amplification ability of the triode.

3. Collect electrons in the collector area.

Due to the large external reverse voltage of the collector junction, the electric field force generated by this reverse voltage will prevent the electrons in the collector region from spreading to the base region, and at the same time pull the electrons that diffuse to the vicinity of the collector junction into the collector region to form the collector main current ICN. In addition, a small number of carriers (holes) in the collector region will also produce drift motion, and the reverse saturation current will flow to the base region, which is represented by ICBO, and its value is small, but it is extremely sensitive to temperature.

Encyclopedia--Voltage amplification.

Encyclopedia--Transistors.

A transistor is composed of two N-type or P-type diodes sandwiched between a layer of P-type or N-type diodes, and is divided into a collector, a base, and an emitter. The collector is responsible for replenishing the energy, the base is responsible for trigger control, and the emitter is responsible for output. Due to its special structure, the amount of electrons injected in the emission region is several times the amount of electrons at the base, when the base signal current is turned on, the emitter current emission is triggered, such as the base enters an electron, the emitter may flow out of several or hundreds of electrons, so as to achieve the so-called current amplification.

1) In order to facilitate the emission of electrons by the emission junction, the doping solubility of the semiconductor in the emission region is much higher than that of the semiconductor in the base region, and the area of the emission junction is small.

2) Although the emission area and the collector area are doped semiconductors of the same property, the doping solubility of the emission area is higher than that of the collector area, and the area of the collector junction is larger than that of the transmitting junction, which is convenient for collecting electrons.

3) The base region of the two PN junctions connecting the emission junction and the collector junction is very thin, and the doping solubility is also very low.

Hello, the most significant function of the transistor is to amplify the signal. It is often used in amplification circuits and oscillation circuits.