Table of Contents
- 1 Why is Collector current zero when base current is zero?
- 2 When the collector current in a transistor in zero the transistor is?
- 3 What is the value of VCE when collector current is zero in CE configuration *?
- 4 Where is VCE in transistor?
- 5 How is VCE cut off calculated?
- 6 What is transistor VCE?
- 7 What is VCE at cut off and VCC at saturation?
- 8 What happens to the collector current at saturation in a transistor?
Why is Collector current zero when base current is zero?
When we required a switching operation from a transistor, we use cutoff region and saturation region of a transistor. When there is no base emitter current(base is connected to positive in this case) it is operating in the cutoff region and collector current is approximately zero at this point.
When the collector current in a transistor in zero the transistor is?
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 causes the collector current to flow when the emitter current is zero?
During the positive half-cycle of the signal, the base is positive with respect to the emitter and hence the base-emitter junction is forward biased. This causes a base current and much larger collector current to flow. This is known as zero signal collector current.
Why is Collector current constant in active region?
The collector current is nearly constant for a given value of base current and is almost independent on the collector to emitter voltage. This is the case in active region. The reason is that the collector current has saturated to its maximum value which the given free charge carriers at the moment can carry.
What is the value of VCE when collector current is zero in CE configuration *?
Transistor is “fully-ON” ( saturation region ) Max Collector current flows ( IC = Vcc/RL ) VCE = 0 ( ideal saturation )
Where is VCE in transistor?
Calculate Vce using the formula Vce= Vcc – [Ie * (Rc + Re)]. Using the numbers from the previous examples, the equation works as follows: Vce = 12 – 0.00053 (3000 + 7000) = 12 – 5.3 = 6.7 volts.
In what region is a transistor operating if the collector current is zero?
Cutoff region
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. The following figure shows a transistor working in cutoff region.
What is VCE saturation?
Vce saturation means Ic is at its maximum value(saturated). Ideally we consider Vce to be zero but in actual it is 0.2 to 0.3 volts for upto 50 mA Ic.
How is VCE cut off calculated?
What is transistor VCE?
The transistor parameter “Vce” signifies the voltage measured between the collector and emitter, which is extremely important because the voltage between the collector and the emitter is the output of the transistor.
Why does collector current go to zero in common emitter configuration?
The reason Collector-Emitter current goes to zero in common Emitter configuration is that the Emitter is connected to the lowest voltage in the circuit. As Collector voltage approaches this common point junction resistances start to limit current, eventually reaching zero when it cannot pull down any further.
What is the relationship between collector current and base current?
Therefore, the collector current is related to the emitter current which is in turn a function of the B-E voltage. The voltage between two terminals controls the current through the third terminal. This is the basic principle of the BJT The collector current and the base current are related by
What is VCE at cut off and VCC at saturation?
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.
What happens to the collector current at saturation in a transistor?
At saturation, collector-base junction no longer remains reverse biased and normal transistor action is lost. If base current is greater than IB ( sat ), then collector current cannot increase because collector-base junction is no longer reverse-biased.