What do you mean by emitter efficiency?

What do you mean by emitter efficiency?

a) The emitter efficiency, is defined as the ratio of the electron current in the emitter, to the sum of the electron and hole current diffusing across the base-emitter junction.

What is emitter injection?

The emitter injection efficiency is the ratio of carriers injected into the base from the emitter (forward minority carrier injection) to total carriers injected from the base into the emitter (reverse minority carrier injection) plus forward injection: γ = ien / (ien + iep)

How is emitter efficiency calculated?

The product of emitter efficiency (γ) and transport factor (β*) for a BJT is equal to:

1. Small signal current gain.
2. High frequency current gain.
3. Power loss in the BJT.
4. Large-signal current gain.

What is the function of emitter in BJT?

The role of the emitter region is to emit or inject current carriers into the base region, which then moves to the collector region of the transistor, where the transistor outputs the current signal. In a bipolar junction transistor, current flows from the emitter to the collector and then out from the collector.

What is injection efficiency of transistor?

Emitter injection efficiency in a BJT transistor defines the efficiency of majority carrier injection from emitter. It is the ratio of current due to emitter majority carriers to the total emitter current. It defines the injection capability of an emitter. Heavily doped region will have high injection factor.

What is the advantage of using emitter degeneration resistance in biasing circuits?

In other words, the addition of this emitter terminal resistance helps control the transistors base biasing using negative feedback, which negates any attempted change in collector current with an opposing change in the base bias voltage and so the circuit tends to be stabilised at a fixed level.

What is current amplification factor?

The current amplification factor or current gain of a transistor is the ratio of output current to the input current. If the transistor is connected on base mode the current gain α=IEIC and if the transistor is connected in common emitter mode, the current gain α=IBIC.

What is emitter degeneration?

Emitter degeneration refers to the addition of a small resistor (R4) between the emitter and the common signal source. In this circuit the base terminal of the transistor is the input, the collector is the output, and the emitter is common to both.

What is the function of emitter?

Emitter: Emitter terminal is the heavily doped region as compared two base and collector. This is because the work of the emitter is to supply charge carrier to the collector via the base. The size of the emitter is more than base but less than the collector.

What is alpha and beta in semiconductors?

Alpha of a transistor is defined as the current gain in the common base configuration which is in turn defined as the ratio of change in the collector current to change in the emitter current. Also, beta is the current gain in Common Emitter configuration.

What is common emitter connection?

Definition: The configuration in which the emitter is connected between the collector and base is known as a common emitter configuration. The input circuit is connected between emitter and base, and the output circuit is taken from the collector and emitter.

What is the purpose of using emitter degeneration resistance?

The aim of an AC signal amplifier circuit is to stabilise the DC biased input voltage to the amplifier and thus only amplify the required AC signal. This stabilisation is achieved by the use of an Emitter Resistance which provides the required amount of automatic biasing needed for a common emitter amplifier.

What is emitter injection efficiency in BJT transistors?

Emitter injection efficiency in a BJT transistor defines the efficiency of majority carrier injection from emitter. It is the ratio of current due to emitter majority carriers to the total emitter current. It defines the injection capability of an emitter.

What is the emitter efficiency of a 1 Ma bipolar transistor?

A bipolar transistor with an emitter current of 1 mA has an emitter efficiency of 0.99, a base transport factor of 0.995 and a depletion layer recombination factor of 0.998. Calculate the base current, the collector current, the transport factor and the current gain of the transistor.

What is the base transport factor of BJT?

Base transport factor is the ratio of collector current to base current of a BJT transistor. That is, it is the ratio of output current to input current in common emitter configuration.

What is the current amplification factor in a BJT transistor?

Current amplification factor in a BJT transistor is defined as the ratio of output current to its input current. In a common base configuration, current amplification factor is the ratio of collector current to the emitter current.