3-2. Bipolar Transistors (BJTs)

There are two types of bipolar transistors: NPN type and PNP type. NPN-type products have low withstand voltage to high withstand voltage. PNP-type products with withstand voltage of 400 V or less, and particularly those with withstand voltage of 200 V or less, are mainstream.
There is an amplification function to convert small signals to large signals. The ratio of collector current IC and base current IB (IC/IB) is called DC current gain, denoted as hFE.
When small current (IB) flows from base to emitter, current of IB x hFE flows from collector to emitter.

Symbol and structure of NPN transistor
Fig. 3-1(a) Symbol and structure of NPN transistor
Symbol and structure of PNP transistor
Fig. 3-1(b) Symbol and structure of PNP transistor

BJTs are current-driven devices driven by base current.

Operation of NPN transistor
 Base current: Current from base to emitter
 Collector current: Current from collector to emitter

Operation of PNP transistor
 Base current: Current from emitter to base
 Collector current: Current from emitter to collector

Chapter III : Transistors

3-1. Types of Transistors
3-3. Bias Resistor Built-in Transistors (BRTs)
3-4. Junction Field-Effect Transistors (JFETs)
3-5. Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs)
3-6. Differences between BJT and MOSFET
3-7. Structure and Operation of MOSFET
3-8. MOSFET Performance Improvement: Decision Factors of RDS(ON)
3-9. MOSFET Performance Improvement: Approach to Low RDS(ON)
3-10. MOSFET Performance Improvement: Super-Junction MOSFETs (SJ-MOS)
3-11. Summary of MOSFET Features by Structure
3-12. Performance of MOSFETs: Drain Current and Power Dissipation
3-13. Performance of MOSFETs: Avalanche Capability
3-14. Performance of MOSFETs: Characteristic of Capacitance
3-15. Performance of MOSFETs: Safe Operating Area(or Area of Safe Operation)
3-16. Insulated-Gate Bipolar Transistors (IGBTs)
3-17. Operation of Insulated-Gate Bipolar Transistors (IGBTs)
3-18. Performance Improvement of IGBTs: Evolution of Vertical Design
3-19. What are RC-IGBTs and IEGTs?
3-20. Application of IGBTs
3-21. Comparison of Forward Characteristics of IGBTs and MOSFETs
3-22. Comparison of Transistors by Structure
3-23. Datasheets of MOSFET: Maximum Ratings
3-24. Datasheets of MOSFET: Electrical Characteristics
3-25. Datasheets of MOSFET: Capacitance and Switching Characteristics
3-26. Datasheets of MOSFET: Body Diode

Related information

A new window will open