Why FET is superior to BJT as amplifier?
FET has no offset voltage when used as switch unlike BJT. FET is relatively immune to radiation but BJT is very sensitive. FET is less noisy compare to BJT. It is more suitable for input stages of low level amplifiers.
What is a better linear amplifier in general a FET or BJT?
While the voltage gain of an FET amplifier is generally less than that obtained using a BJT amplifier, the FET amplifier provides a much higher input impedance than that of a BJT configuration. Output impedance values are comparable for both BJT and FET circuits.
What is the difference between BJT FET and Mosfet?
BJTs, FETs and MOSFETs are all active semiconductor devices, also known as transistors. BJT is the acronym for Bipolar Junction Transistor, FET stands for Field Effect Transistor and MOSFET is Metal Oxide Semiconductor Field Effect Transistor. BJTs usually function as current controlling switches.
What are the basic differences between BJT and JFET?
Difference between BJT And JFET
| BJT | JFET |
|---|---|
| Voltage driven device. The current through the two terminals is controlled by a voltage at the third terminal (gate). | Current driven device. The current through the two terminals is controlled by a current at the third terminals (base). |
| Low noise level. | High noise level. |
What are the disadvantages of FET over BJT?
Drawbacks or disadvantages of FET ➨It has relatively lower gain-bandwidth product compare to BJT. ➨Transconductance is low and hence voltage gain is low. ➨FET has slower switching times compare to BJT. The internal junction capacitance of FET is responsible for high delay times.
Which has more gain BJT or FET?
BJTs offer greater gain at the output than FETs. The gain (or transconductance) of FETs are smaller than for BJTs.
What are the advantages of FET when compared to BJT?
FETs are more temperature stable than BJTs. FETs are generally easier to fabricate than BJTs. Greater numbers of devices can be fabricated on a single chip (i.e., increased packing density is possible). FETs react like voltage-controlled variable resistors for small values of drain-to-source voltage.
What are the similarities between BJT and FET?
A BJT or FET both shares the same category of transistors. These transistors have the property of both conduction as well as insulation. BJT, as well as FET, consists of three basic terminals in it. These transistors are found everywhere as the basic components of electronic systems.
What are the advantages of BJT?
Advantages of BJT :
- They have a better voltage gain.
- They have a high current density.
- They have a low forward voltage.
- It can be operated in low to high power application.
- BJT has a large gain bandwidth.
- BJT shows better performance at high frequency.
What are the advantages of FET over BJT?
The advantages of FETs relative to BJTs are summarized as follows:
- FETs are voltage-sensitive devices with high input impedance (on the order of 107 to 1012 Ω).
- One class of FETs (JFETs) generates lower noise than BJTs.
- FETs are more temperature stable than BJTs.
- FETs are generally easier to fabricate than BJTs.
What is the difference between FET and JFET?
FET stands for “Field Effect Transistor” it is a three terminal uni polar solid state device in which current is control by an electric field. P-Channel JFET is similarly is constructed except that it use P- type of bar and two N- types of junctions.
What are the advantages and disadvantages of FET over BJT?
Advantages and disadvantages of FET
- FET has a high input impedance of several megaohms.
- FET has less effect by radiation than BJT.
- Temperature stable than BJT.
- Less noise compare to BJT.
- Can be fabricated with fewer processing.
- Smaller in size.
- Longer life.
- High efficiency.
What’s the difference between a BJT and a FET?
BJTs offer greater gain at the output than FETs. The gain (or transconductance) of FETs are smaller than for BJTs. BJTs are larger in size and therefore take up more physical space than FETs normally. FETs can be manufactured much smaller than BJTs. This is especially important for integrated circuits that are composed up of many transistors.
Which is easier to analyze MOSFET or BJT?
BJT and MOSFET differential amplifiers with active loads Due to design processes and the nature of the devices involved, BJT circuits are “simpler” to analyze than their FET counterparts, whose circuits require a few extra steps when calculating performance parameters.
How does a BJT differential AMP bias a circuit?
BJT differential amp with current mirror biasing In order to properly bias this circuit, it is necessary to include . Two things are accomplished by including in our circuit. One of them is that we can induce the current in , and thus, the current in .
Which is the input impedance of a BJT transistor?
Input impedance is the amount of resistance that a transistor offers on its input terminal. For BJTs, this would be the base terminal; for FETs, this would be the gate terminal. BJTs offer much less resistance to their input terminal than FETs. Because of this much lower resistance, it draws current from the power supply powering the base.