What is a bipolar transistor, its characteristics, principles, classification, operating procedures, and development trends 2

Classification of bipolar transistors:

According to the device structure, bipolar transistors can be divided into the following two types:

(1) NPN bipolar transistor: composed of two P-type semiconductor layers sandwiched between an N-type semiconductor layer.

(2) PNP bipolar transistor: composed of two N-type semiconductor layers sandwiched between a P-type semiconductor layer.

According to device usage, bipolar transistors can be divided into the following two types:

(1) Amplification type bipolar transistor: used in signal amplification circuits.

(2) Switching bipolar transistor: used for switching circuits.

Operating procedures for bipolar transistors:

(1) Forward bias: Ground the N-type material and apply a positive voltage to the P-type material, so that the PN junction is forward biased and current can flow through the transistor.

(2) Reverse bias: Connect the N-type material to a positive voltage and the P-type material to ground, so that the PN junction is reverse biased and current cannot flow through the transistors.

(3) Amplification: In the case of forward bias, changes in the input signal will cause changes in the base current, thereby controlling the output current of the transistor and achieving signal amplification.

(4) Switch: Under forward bias, controlling the base current within a certain range can achieve switch control of the output current.

The development trend of bipolar transistors:

(1) Integration: The integration level of bipolar transistors is increasing, allowing for the integration of multiple transistors together, thereby achieving more complex circuit functions.

(2) High frequency: The performance of bipolar transistors is becoming increasingly superior in the high frequency range, enabling higher frequency applications.

(3) Low power consumption: The power consumption of bipolar transistors is decreasing, enabling more energy-efficient applications.

(4) Large Capacity: The capacity of bipolar transistors is increasing, enabling more efficient applications.