Table of Contents
- 1 When a BJT is operating in the cut off and saturation regions?
- 2 How does a BJT behave in saturation region?
- 3 What is cutoff region transistor?
- 4 What are output characteristics of BJT?
- 5 What happens in active region of BJT?
- 6 What is saturation and cutoff in transistors?
- 7 What is the most important characteristic of BJT?
- 8 What is the difference between a BJT and a PNP?
When a BJT is operating in the cut off and saturation regions?
When the transistor is either in saturation or cutoff modes, it dissipates little power. When in cutoff, there is no current flow between collector and emitter thus P = Vce ∗ Ic = 0. When in saturation, the current may be high, but Vce is very small, keeping the power dissipated by the transistor very low.
What is saturation and cut off region?
At cut off, the base-emitter junction no longer remains forward biased and normal transistor action is lost. The collector-emitter voltage is nearly equal to VCC i.e. VCE (cut off) = VCC. (ii) Saturation. The point where the load line intersects the IB = IB(sat) curve is called saturation.
How does a BJT behave in saturation region?
In deep saturation, the BJT does not behave as a voltage-controlled current source. VCE is ~constant. The emitter junction is forward biased. are enhanced (by ) at the edges of the emitter-junction depletion region.
What is cutoff region of BJT?
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 cutoff region transistor?
Cutoff region 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.
What is cutoff region BJT?
What are output characteristics of BJT?
The output characteristics of BJT can be divided into three areas – cut-off, saturation and active region. In the cut-off region both collector-base and emitter-base pn-junctions are reverse-biased – transistor is off.
When operated in cutoff and saturation the transistor acts like a?
The four transistor operation modes are: Saturation — The transistor acts like a short circuit. Current freely flows from collector to emitter. Cut-off — The transistor acts like an open circuit.
What happens in active region of BJT?
Active region: In this region, the base emitter junction is forward biased and the base-collector junction is reverse biased. This region is the normal transistor operation mode for amplification, and is characterized by the transistor current gain value, beta.
What is the saturation region?
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. The figure below shows a transistor working in saturation region.
What is saturation and cutoff in transistors?
Saturation — The transistor acts like a short circuit. Current freely flows from collector to emitter. Cut-off — The transistor acts like an open circuit. No current flows from collector to emitter. Active — The current from collector to emitter is proportional to the current flowing into the base.
When does a BJT operate in the saturation region?
The BJT operates in the saturation region when its collector current is not dependent on the base current and has reached a maximum. The condition for this to happen is that both the base-emitter and the base-collector junctions should be forward-biased.
What is the most important characteristic of BJT?
The most important characteristic of the BJT is the plot of the collector current, the collector-emitter voltage, CE, for various values of the base current, I
What is the mode of operation in BJT transistor characteristic curve?
This mode of operation is active or linear regions of operation in the BJT transistor characteristic curve. By increase the V CE beyond 0.7v, the collector current remains constant for a given value of base current I B. Increasing the V CE can cause a very slight increase in I C because of the widening of the base-collector depletion region.
What is the difference between a BJT and a PNP?
The BJT is fabricated with three separately doped regions. The npn device has. one p region between two n regions and the pnp device has one n region between two p. regions. The BJT has two junctions (boundaries between the n and the p regions).