Table of Contents
How can BJT be used as switch?
The transistor can be used as a switch if biased in the saturation and cut-off regions. This allows current to flow (or not) in other parts of a circuit. Because a transistor’s collector current is proportionally limited by its base current, it can be used as a sort of current-controlled switch.
How can we make transistor as a switch?
For a PNP transistor, the Emitter potential must be positive with respect to the Base. Then the transistor operates as a “single-pole single-throw” (SPST) solid state switch. With a zero signal applied to the Base of the transistor it turns “OFF” acting like an open switch and zero collector current flows.
How diode is used as a switch?
Whenever a specified voltage is exceeded, the diode resistance gets increased, making the diode reverse biased and it acts as an open switch. Whenever the voltage applied is below the reference voltage, the diode resistance gets decreased, making the diode forward biased, and it acts as a closed switch.
How PNP transistor works as a switch?
PNP Transistor as a Switch PNP transistor works same as NPN for a switching operation, but the current flows from the base. This type of switching is used for negative ground configurations. For the PNP transistor, the base terminal is always negatively biased with respect to the emitter.
Where is BJT used?
The main basic function of a BJT is to amplify current it will allow BJTs are used as amplifiers or switches to produce wide applicability in electronic equipment include mobile phones, industrial control, television, and radio transmitters. There are two different types of BJTs are available, they are NPN and PNP.
Which is better switch BJT or FET?
Therefore, the gain of the BJT amplifier is very high as compared to FET. Since the current flow is due to electrons as well as holes, the recovery time i.e. the time it takes to switch off and switch on is large as compared to FET. Therefore, the BJT has a low switching speed as compared to FET. BJT is not suitable for very high frequency.
What are the switching characteristics of BJT?
A BJT is a bipolar junction transistor, which is capable of handling two polarities (holes and electrons), it can be used as a switch or as an amplifier and also known as a current control device. The following are the characteristics of a Power BJT, they are It has a larger size , so that maximum current can flow through it
How is BJT used as a voltage amplifier?
The three terminals of the BJT are the base, the collector and the emitter. A BJT is a type of transistor that uses both electrons and holes as charge carriers. A signal of small amplitude if applied to the base is available in the amplified form at the collector of the transistor. This is the amplification provided by the BJT.
What is the difference between BJT and E-MOSFET?
The BJT is a bipolar junction transistor whereas MOSFET is a metal oxide semiconductor field-effect transistor.