Category: FIELD EFFECT TRANSISTORS

MOSFET Construction and Characteristics

MOSFET Construction and Characteristics: Figure 9-28 shows the MOSFET Construction and Characteristics of a metal oxide semiconductor FET (MOSFET), also known as an insulated gate FET. Starting with a high-resistive p-type substrate, two blocks of heavily-doped n-type material are diffused into the substrate, and then the surface is coated with a layer of silicon dioxide. […]

FET Amplification

FET Amplification: Consider the n-channel FET Amplification circuit in Fig. 9-26. Note that drain-source terminals are provided with a dc supply (VDD), connected via the drain resistor (R1). The gate-source junctions are reverse-biased by the gate voltage (VG). An ac signal generator (with voltage vf) is connected in series with the gate terminal. As already […]

FET Datasheet Specifications

FET Datasheet Specifications: Maximum Ratings –¬†A¬†portion of a FET Datasheet Specifications is reproduced in Fig. 9-17. As with other device data sheets, a device type number and brief description is usually given at the start. Maximum ratings follow, and then the electrical characteristics are stated for specific bias conditions. From Fig. 9-17, the maximum drain-source […]

JFET Characteristics

JFET Characteristics: Depletion regions – An n-channel JFET Characteristics block representation is shown in some detail in Fig. 9-6. With a drain-source voltage applied as illustrated, ID flows in the direction shown producing voltage drops along the channel. Consider the voltage drops from the source terminal (S) to points A, B. and C within the […]

Junction Field Effect Transistor Theory

Junction Field Effect Transistor Theory: n-Channel JFET – The operating principle of an n-channel Junction Field Effect Transistor Theory (JFET) is illustrated by the block representation in Fig. 9-1(a). A piece of n-type semiconductor material, referred to as the channel, is sandwiched between two smaller pieces of p-type (the gates). The ends of the channel […]