What Is Meant By Active Region?

What is active mode in transistor?

Typically we want to have a transistor to operate in what is called active mode.

Active mode is when the Base-Emitter junction is forward biased and the Base-Collector Junction is Reverse biased.

For the npn this means that the Base has a higher potential than the Emitter and a lower potential than the collector..

How does a BJT work?

Bipolar Transistors are current regulating devices that control the amount of current flowing through them from the Emitter to the Collector terminals in proportion to the amount of biasing voltage applied to their base terminal, thus acting like a current-controlled switch.

Why BJT is called bipolar?

REVIEW: Bipolar transistors are so named because the controlled current must go through two types of semiconductor material: P and N. The current consists of both electron and hole flow, in different parts of the transistor. Bipolar transistors consist of either a P-N-P or an N-P-N semiconductor “sandwich” structure.

What is cut off in transistor?

A transistor in cutoff mode is off — there is no collector current, and therefore no emitter current. It almost looks like an open circuit. To get a transistor into cutoff mode, the base voltage must be less than both the emitter and collector voltages.

Is VBE always 0.7 V?

VBE is the voltage that falls between the base and emitter of a bipolar junction transistor. VBE is approximately 0.7V for a silicon transistor. For a germanium transistor (which is more rare), VBE is approximately 0.3V. Again, this formula, can be used for either silicon or germanium transistors.

How do you know if a transistor is in active mode?

Typically we want to have a transistor to operate in what is called active mode. Active mode is when the Base-Emitter junction is forward biased and the Base-Collector Junction is Reverse biased. For the npn this means that the Base has a higher potential than the Emitter and a lower potential than the collector.

What is CC configuration?

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

What is emitter efficiency?

The emitter efficiency, gE, is defined as the ratio of the electron current in the emitter, IE,n, to the sum of the electron and hole current diffusing across the base-emitter junction, IE,n + IE,p.

What is the PNP transistor?

PNP Transistor. Definition: The transistor in which one n-type material is doped with two p-type materials such type of transistor is known as PNP transistor. It is a current controlled device. The small amount of base current controlled both the emitter and collector current.

What is meant by cut off region?

In cut off region, both emitter to base and base to collector junction is in the reverse bias and no current flows through the transistor. … In the saturation region, both the junctions are in forwarding bias, and the transistor acts as a closed switch. In cut off region the output of the transistor VCE=0.

What is the use of active region of transistor?

In the active region, emitter to the base junction is forward biased and the base to collector junction is reverse biased. In the active region, the transistor acts as an amplifier.

What is reverse active region?

Just as saturation is the opposite of cutoff, reverse active mode is the opposite of active mode. A transistor in reverse active mode conducts, even amplifies, but current flows in the opposite direction, from emitter to collector. The downside to reverse active mode is the β (βR in this case) is much smaller.

What is BJT and its working?

A bipolar junction transistor is a three-terminal semiconductor device that consists of two p-n junctions which are able to amplify or magnify a signal. It is a current controlled device. The three terminals of the BJT are the base, the collector and the emitter.

What is quiescent operating point?

The operating point of a device, also known as a bias point, quiescent point or Q-point, is the steady-state DC voltage or current at a specified terminal of an active device such as a transistor with no input signal applied.

What is the saturation region condition?

Saturation region This is the region in which transistor tends to behave as a closed switch. The transistor has the effect of its collector and Emitter being shorted. The collector and Emitter currents are maximum in this mode of operation.

How do you determine the region of a transistor?

If the collector voltage is below the base voltage, the transistor is typically in the saturated region. You could also look at the current gain (i.e. collector current divided by base current). If the current gain is much higher than unity, the NPN is typically operating in the non-saturated region.

What is active region in BJT?

Active region is one in which Base emitter junction is forward biased and Base Collector junction will be reverse biased in a transistor. In NPN transistor when you bias it in active region the currents flowing through it will be as follows. [/ezcol_2third_end] The currents flowing through the three terminals of BJT …

What are the three operating regions of a transistor?

A BJT consists of three differently doped semiconductor regions: the emitter region, the base region and the collector region. These regions are, respectively, p type, n type and p type in a PNP transistor, and n type, p type and n type in an NPN transistor.

What is active saturation and cutoff region?

The region between cut off and saturation is known as active region. In the active region, collector-base junction remains reverse biased while base-emitter junction remains forward biased. Consequently, the transistor will function normally in this region.

What is the symbol of BJT?

The basic symbols of BJT are n-type and p-type. Electronic current is conducted by both free electrons and holes in bipolar junction transistor.

What is iC saturation?

Deep saturation region: 0.1 < vCE < 0.3 V (Si) or vCE≈ 0.2 V = Vsat (Si), iC is smaller than its active-mode level (iC < β iB). o Called saturation as iC is set by outside circuit & does not respond to changes in iB. 3.