Question: What Is Meant By Cut Off Region?

What are the three 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 cutoff current?

Collector Cutoff Current – ICEx or ICEv Collector cutoff current is the IC that still flows when the specified VC and a specified reverse bias is applied. It is normally less than either ICEO or ICER (collector current with the base open, or with the base resistively connected to the emitter).

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 transistors work?

A transistor works when the electrons and the holes start moving across the two junctions between the n-type and p-type silicon. … By turning a small input current into a large output current, the transistor acts like an amplifier. But it also acts like a switch at the same time.

What is meant by transistor?

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.

What is knee voltage?

In the forward region of the graph, the voltage at which the current starts to increase quickly is called the knee voltage of the diode. Study of a diode circuit usually comes down to determining if the diode voltage is higher or lower than the knee voltage.

What is cut off current in fuse?

(a) A fuse cuts off current when the current exceeds a safe value (due to short circuiting or overloading). When the current becomes large, it heats the fuse wire too much. Since the melting point of fuse wire is low, it melts and breaks the circuit. Thus, current in the circuit is cut off.

What is meant by active region?

Active region This is also called as linear region. A transistor while in this region, acts better as an Amplifier. This region lies between saturation and cutoff. The transistor operates in active region when the emitter junction is forward biased and collector junction is reverse biased.

What is the PNP transistor?

The PNP Transistor is the exact opposite to the NPN Transistor device we looked at in the previous tutorial. … Then, PNP transistors use a small base current and a negative base voltage to control a much larger emitter-collector current.

What is quiescent operating point?

The operating point of a device, also known as bias point, quiescent point, or Q-point, is the DC voltage or current at a specified terminal of an active device (a transistor or vacuum tube) with no input signal applied. A bias circuit is a portion of the device’s circuit which supplies this steady current or voltage.

What is IC saturation?

Yes – there are two different meanings of the term “saturation” – dependent on the transistor type: BJT or FET. … BJT (with collector resistor): Increasing Vbe (or Ib) leads to rising collector current Ic, which causes a continuous decrease of the collector-emitter voltage Vce – until a lower limit is reached at app.

Why BJT is called bipolar?

Simply put, a BJT is a three-terminal semiconductor device. The name “bipolar” comes from the fact that this type of transistor contains two types of semiconductor material—one positive type (p-type) and one negative type (n-type)—through which a current flows. Bipolar junction transistors usually contain silicon.

What is a fusing current?

This is the minimum current that will cause the fuse element to heat up melt or blow.

What is cut off region in transistor?

Whenever we observe the terminals of a BJT and see that the emitter-base junction is not at least 0.6-0.7 volts, the transistor is in the cutoff region. In cutoff, the transistor appears as an open circuit between the collector and emitter terminals.

What is NPN and PNP transistor?

PNP transistor is made up of two P-type material layers with a layer of sandwiched of N-type. The NPN transistor is made up of two N-type material layers with a layer of sandwiched of P-type. In an NPN-transistor, a +ve voltage is set to the collector terminal to generate a flow of current from the collector.