What is reason behind early effect in BJT?

A large collector base reverse bias is the reason behind early effect manifested by BJTs. The depletion layer penetrates more into the base as the base is lightly doped increasing the concentration gradient in the base.

What is early effect in Mosfet?

In bipolar devices, a similar increase in current is seen with increased collector voltage due to base-narrowing, known as the Early effect. The similarity in effect upon the current has led to use of the term “Early effect” for MOSFETs as well, as an alternative name for “channel-length modulation”.

Why does emitter current increase due to early effect?

The concentration gradient of minority charge carriers is increased within the base. Since the hole current injected across the emitter is proportional to the gradient of the minority carriers at the emitter junction, the Emitter-current increases with increasing reverse collector voltage.

What is Early effect in BJT Mcq?

Early Effect MCQ Question 7 Detailed Solution Early effect is the variation in the width of the base in a Bipolar Junction Transistor (BJT) due to a variation in the applied base-to-collector voltage.

What is punch through effect?

A very large subthreshold swing implies that the device cannot be turned off. This phenomenon is called punchthrough and occurs roughly when the source and drain depletion regions meet. Since the depletion region becomes wider at larger drain biases, the onset of punchthrough is reached sooner.

What is early effect?

The Early effect, named after its discoverer James M. Early, is the variation in the effective width of the base in a bipolar junction transistor (BJT) due to a variation in the applied base-to-collector voltage.

Which among the following indicate early effect in BJT?

A large collector base reverse bias is the reason behind the early effect by the BJTs. As reverse biasing of the collector to base junction increases, the depletion region penetrates more into the base, as the base is lightly doped.

Is early effect good or bad?

Early effect causes an increase in collector current. BJT’s are generally considered as current controlled current sources. As emitter current increases,collector current increases as well.

What is body effect?

Body effect refers to the change in the transistor threshold voltage (VT) resulting from a voltage difference between the transistor source and body. Body effect occurs when the body or substrate of the transistor is not biased at the same level as that of the source.

What is the “early effect?

It turns out that an analogous phenomenon affects the operation of a bipolar junction transistor. A BJT doesn’t have a channel, though, so we need a different name; at some point people decided on the “Early effect,” after James Early, though you will see shortly that we could also call it “effective-base-width modulation.”

What effect does the early effect have on the collector current?

Early effect causes an increase in collector current. BJT’s are generally considered as current controlled current sources. As emitter current increases,collector current increases as well.Early effect causes collector current to change in accordance with the collector voltage.

What is early effect and early effect of transistor?

Both these factors increase the collector or “output” current of the transistor with an increase in the collector voltage, but only the second is called Early effect. This increased current is shown in Figure 2.

What is the early effect in a BJT?

Top: NPN base width for low collector–base reverse bias; Bottom: narrower NPN base width for large collector–base reverse bias. Hashed areas are depleted regions. Figure 2. The Early voltage ( VA) as seen in the output-characteristic plot of a BJT. The Early effect, named after its discoverer James M.