Here are some main characteristic differences between transistor PNP and NPN：
NPN transistor:
Current direction: Electrons flow from the emitter to the collector, and holes flow from the base to the emitter.
Base bias: Requires a relatively high level (positive voltage) to conduct.
It is often used in common emitter amplifier circuits and has a relatively high current gain.
PNP transistor:
Current direction: Holes flow from the emitter to the collector, and electrons flow from the collector to the base.
Base bias: Requires a relatively low level (negative voltage) to conduct.
It is used in cooperation with NPN in some complementary circuit designs.
In practical applications, their characteristic differences will affect the design and function realization of the circuit. For example, in some push-pull amplifier circuits, both NPN and PNP transistors will be used simultaneously to achieve better performance.
The main differences between common transistors PNP and NPN are as follows:
Current direction:
NPN: The current flows from the collector to the emitter, and electrons flow from the emitter to the collector, and the base current controls the collector current.
PNP: The current flows from the emitter to the collector, and holes flow from the collector to the emitter, and the base current also controls the collector current, but in the opposite direction.
Base bias:
NPN: It requires a positive base voltage to conduct.
PNP: It requires a negative base voltage to conduct.
Application characteristics:
NPN is more common and widely used in many electronic circuits.
PNP is often used in combination with NPN, such as in complementary circuits.
Performance manifestation:
In some cases, there may be certain differences in parameters such as their current gain.
Symbol representation: The symbols of NPN and PNP in the circuit diagram are different and easy to distinguish.