INTRODUCTION TO FIELD EFFECT TRANSISTORS (PART 28)

In this video we explore Field-Effect Transistors (FETs) and how they compare to Bipolar Junction Transistors (BJTs). We start with a clear comparison of BJTs and FETs, highlighting differences in control mechanism, input impedance, noise, switching behavior, and biasing requirements. Then we introduce FETs—what they are, why they matter, and how gate voltage controls the channel. Next, we give an accessible overview of FET fabrication and operation, explaining how device structure creates depletion and enhancement modes and how channels are formed during manufacturing. We classify the main FET families (MOSFET, JFET, MESFET, HEMT, and others), outlining typical uses for each. Finally, we take a focused look at JFETs: their structure, operation, I–V characteristics, and common applications. Whether you’re studying electronics, preparing for interviews, or designing circuits, this video gives a practical, easy-to-follow foundation for understanding FETs and when to choose them over BJTs.