When it comes to the bipolar transistor (Bipolar Junction Transistor, referred to as BJT) this kind of product, many peers will be curious about the difference between it and the field effect transistor in the end where? In this article, we will popularize this issue for you, first of all, we will have a detailed understanding of the product characteristics of bipolar transistors:

　　Bipolar transistor refers to a PN junction based on a silicon-based electronic components, is a widely used in electronic circuits in the triode, mainly composed of three doped monocrystalline silicon electrodes, respectively, is the base, the emitter and collector, with current amplification and switching control functions, the following are a few features of bipolar transistors:

　　1, voltage and current amplification

　　Bipolar transistor has a strong voltage and current amplification ability, in the circuit, when a small current flows through the control terminal, it can control the large current out of the output terminal, to achieve the current amplification, can be a weak signal amplified to a certain amplitude, which can enhance the circuit's signal processing capabilities.

　　2, high-speed on and off

　　Bipolar transistor has a very fast on and off ability, in the circuit, through the control terminal voltage change, can make the bipolar transistor in the microsecond level to complete the turn on or turn off the operation, so commonly used in high-speed circuits.

　　3、Good parameter stability

　　The parameter stability of bipolar transistor is very good, in the manufacturing process, the accuracy of each transistor parameter (such as current amplification factor, extreme voltage, etc.) can be controlled, so it can be realized in batch manufacturing, and it can ensure the consistency and reliability of product parameters.

　　4、Strong voltage resistance

　　The extreme voltage of bipolar transistor can reach more than several hundred volts, and its voltage resistance and stability are also very strong, so it can be used as a key component in high-voltage circuit.

　　5、Strong high-power capability

　　Since the bipolar transistor can withstand high electrical connection and high current draw, it can be used as a key component in high power circuits.

　　Difference between bipolar transistor and field effect transistor

　　1. Product structure:

　　Bipolar transistor has three different doped semiconductor regions, namely, the emitter, base and collector, usually NPN or PNP type transistor, while the field effect transistor is made up of multiple levels of different doped areas, mainly composed of a SOURCE and a DRAIN electrode, which controls the current between the two electrodes through a control gate.

　　2, working principle:

　　In a bipolar transistor, the base controls the flow of current between the emitter and the collector, a device that controls the current, when the current flows to the base, as it is controlled, it can bleed the current out of the collector, BJT has an irreplaceable role in the field of amplification and switching circuits.

　　However, in FETs, instead of controlling the current by the current, the current is controlled by the electric field, and its gate voltage regulates the nature of the channel resistance, which in turn controls the flow of current between the drain-source, FETs are commonly used as amplifiers, switches, and regulating devices in circuits with high input resistance and noise level requirements.

　　3, application areas:

　　Due to the bipolar transistor amplification and frequency response characteristics of superior, commonly used in audio and video amplifiers and switching circuits, field effect transistor due to its high input impedance, low output impedance, fast, commonly used in low noise amplifiers and switches, but also as a high-frequency circuit-oriented design of amplifiers, oscillators and switching circuits.

　　4, operating characteristics:

　　Bipolar transistor in the base to get the application of its amplification performance by its base current control, it should be noted that its circuit characteristics and temperature have a relationship between the shortcomings of the BJT in the degree of amplification, operating conditions, conversion rate and finesse deviation. Whereas, in FET circuits, what comes into play is an electric field, whose input resistance is greater than that of the BJT, and therefore, it is very useful to improve its properties in terms of linearity characteristics, noise reduction, etc.

　　In summary, bipolar transistors and field effect transistors are different in terms of structure, operating principle, application range, operating characteristics, etc. Both have their own advantages and disadvantages, and are suitable for different fields and applications. Which one to choose depends on the specific application requirements, and at the same time, according to the combination of advantages and disadvantages, selection and application, in order to achieve the best results.