Can A Transistor Base Emitter Junction Be Used As Zener Diode?

Where would a diode be used?

For example, diodes are used to regulate voltage (Zener diodes), to protect circuits from high voltage surges (avalanche diodes), to electronically tune radio and TV receivers (varactor diodes), to generate radio-frequency oscillations (tunnel diodes, Gunn diodes, IMPATT diodes), and to produce light (light-emitting ….

Is transistor a semiconductor?

A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit.

Why VCE SAT is 0.2 V?

Because the charge carriers injected from the base effectively eliminate the depletion zone between the collector and emitter. The collector current doesn’t have to overcome the P-N junction potential because the base current has neutralized it.

What is ΒDC equal to?

βdc is the amplification factor by which the base current gets amplified by. So the total output current, IC will be IC=βdc x IB.

Why is base current small in transistor?

Few electrons injected by the emitter into the base of an NPN transistor fall into holes. … Most of the emitter current of electrons diffuses through the thin base into the collector. Moreover, modulating the small base current produces a larger change in collector current.

What is base emitter junction?

the base emitter junction is forward biased and the base collector junction is reverse biased. When a current flows through the base emitter junction, a current also flows in the collector circuit. … The emitter in the n-p-n device is made of n-type material and here the majority carriers are electrons.

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.

What is NPN vs PNP?

With respect to sensors, an NPN device is one that can switch the negative side of the circuit while a PNP device switches the positive side. … NPN sensors are sometime called “sinking sensors” because they sink ground to the output. The term “load” identifies the device the sensor powers.

When would you use a zener diode?

Zener diodes are widely used as voltage references and as shunt regulators to regulate the voltage across small circuits. When connected in parallel with a variable voltage source so that it is reverse biased, a Zener diode conducts when the voltage reaches the diode’s reverse breakdown voltage.

Why is VBE 0.7 V?

For an unbiased transistor, considering only the BE junction which is a pn junction diode, 0.7V is the potential barrier. In an npn transistor base is positive(p) and emitter is negative(n). … But in a pnp transistor the base is negative(n) and emitter is positive(p) so the vbe=-0.7V.

Why transistor is not used as rectifier?

Why transistor can not be used as rectifier? … Since base is thin one and lightly doped, either of the two segment does not work properly as p-n junction diode, which is required for a rectifier. That is why, a transistor can not be used as a rectifier.

What is rectification by diode and transistor?

THE TRANSISTOR RECTIFIER Rectification of alternating current with a single transistor has been considered. This simple circuit consisting of a transistor, a biasing diode and a few resistors can rectify a.c as low as 0.3V or even less.

How do you determine if diode is on or off?

If the voltage across a diode is negative, no current can flow*, and the ideal diode looks like an open circuit. In such a situation, the diode is said to be off or reverse biased. As long as the voltage across the diode isn’t negative, it’ll “turn on” and conduct current.

What is the difference between a diode and rectifier?

Diode is an electronic component that allows the current to flow in only one direction. It is a two terminal semiconductor device. Rectifier is a device that is used to convert an AC voltage to a DC voltage. A diode is used as a switch and a rectifier is used for the conversion of an AC voltage to a DC voltage.

What is the difference between PNP and NPN?

The main difference between the NPN and PNP transistor is, an NPN transistor turns on when the current flows through the base of the transistor. In this type of transistor, the current flows from the collector (C) to the emitter (E). A PNP transistor turns ON, when there is no current at the base of the transistor.

What is the advantage of diode?

Following are the benefits or advantages of Diode: ➨It functions as rectifier in order to convert alternating current into direct current. ➨It is used to suppress voltage spikes. Moreover it is used to protect electronic components which are vulnerable to reverse voltages.

Can a transistor be used as a diode?

Since a bipolar transistor is essentially two diodes, it can function as such. However, since bipolar transistors are not designed to be used as diodes, using them as diodes might cause a problem in terms of current and other ratings. … Use dedicated diodes for typical diode applications instead of bipolar transistors.

Can a transistor be used as a rectifier yes or no?

A transistor can be used as a rectifier. When you connect base-emitter or base-collector region and use it as a diode, a transistor can work as a low current rectifier.

What is the application of a diode?

Applications and Uses of diodes The most basic function would be changing AC current to DC current by removing some part of the signal. This functionality would make them rectifiers. They are used in electrical switches and are used in surge protectors because they can prevent a spike in the voltage.

What happens when a diode is shorted?

The multimeter displays OL when a good diode is reverse-biased. The OL reading indicates the diode is functioning as an open switch. A bad (opened) diode does not allow current to flow in either direction. … A shorted diode has the same voltage drop reading (approximately 0.4 V) in both directions.

Why is Zener diode always reverse biased?

Zener diodes are highly doped diodes. This means their behavior in forward bias will be same as a normal diode. But while in reverse bias their junction potential is increased. … So that means when the voltage crosses 6V then the diode is in Reverse breakdown and hence the current through the diode increases rapidly.