What is the condition for operating a transistor in active region?

What is the condition for operating a transistor in active region?

Unlike the resistors, which have a linear relation between voltage and current, the transistors are nonlinear devices. In order to operate in active mode, the transistor’s voltage in base-emitter junction must be greater than zero while in base-collector mode must be negative.

Is the transistor biased in the active region?

The collector to base feedback configuration ensures that the transistor is always biased in the active region regardless of the value of Beta (β). The DC base bias voltage is derived from the collector voltage VC, thus providing good stability.

What are operating conditions for transistor?

Cut-off Region Here the operating conditions of the transistor are zero input base current ( IB ), zero output collector current ( IC ) and maximum collector voltage ( VCE ) which results in a large depletion layer and no current flowing through the device. Therefore the transistor is switched “Fully-OFF”.

What are the biasing conditions?

In forward biased conditions, the current initially starts to flow through the Schottky barrier, after which conductivity modulation occurs with increasing forward bias larger than the built-in potential of n+p junction applied.

When the transistor operates in active region mode it behaves as?

A transistor in an active region behaves like an amplifier. To achieve amplifying action of the transistor its input and output junctions must be biased accordingly. Complete answer: A transistor is a three terminal device that has an emitter, base, and a collector.

What is a transistor biasing?

Transistor Biasing is the process of setting a transistors DC operating voltage or current conditions to the correct level so that any AC input signal can be amplified correctly by the transistor.

How biasing is done for a transistor?

Transistor biasing can be achieved either by using a single feed back resistor or by using a simple voltage divider network to provide the required biasing voltage. The following are five examples of transistor Base bias configurations from a single supply ( Vcc ).

What is the need of biasing in transistor?

Transistor biasing makes analog and digital operation of a transistor possible. Without transistor biasing, BJT amplifiers fail to deliver the required output across load terminals. The optimum value of transistor bias voltage is equal to two times the required AC output voltage peak.

What is transistor active region?

Active region is that region in which emitter base junction is forward bias while collector base junction is also forward bias.

What bias conditions must exist for a transistor to operate in cutoff?

A. The emitter-base junction must be reverse-biased, and the collector-base junction must be forward biased.

What is transistor biasing explain different operating conditions for a transistor?

Why is transistor biasing?

What is the active region of a transistor?

Active region is one in which Base emitter junction is forward biased and Base Collector junction will be reverse biased in a transistor. Was this answer helpful?

Why is DC biasing needed in a transistor?

If appropriate DC voltages and currents are given through BJT by external sources, so that BJT operates in active region and superimpose the AC signals to be amplified, then this problem can be avoided. The given DC voltage and currents are so chosen that the transistor remains in active region for entire input AC cycle. Hence DC biasing is needed.

When does the transistor operate in the cutoff region?

The transistor operates in cutoff region when both the emitter and collector junctions are reverse biased. As in cutoff region, the collector current, emitter current and base currents are nil, we can write as.

What makes a transistor behave as an open switch?

This is the region in which transistor tends to behave as an open switch. The transistor has the effect of its collector and base being opened. The collector, emitter and base currents are all zero in this mode of operation. The following figure shows a transistor working in cutoff region.