17 January 2018

Difference between IGBT and SCR

Before we learn about the difference between IGBT and SCR first let us check out what is full form of IGBT and what is the full form of SCR. We already know that IGBT process is high input impedance like PMOSFET and has low on-state power loss as in a BJT, but in  thyristor (SCRs) are usually chosen so that their break over voltage is so far beyond the greatest voltage expected to be experienced from the power source, so that it can be turned on only by an intentional voltage pulse applied to the gate terminal. 

So here this article gives information about the difference between IGBT and Thyristor  called (SCR)  to know more detail about IGBT and thyristor :


Difference between IGBT and Thyristor


Meaning : 

IGBT called an Insulated gate bipolar transistor, While Thyristor also called SCR known as silicon controlled rectifier.

Definition :

IGBT : IGBT has been developed by combining the best qualities of both BJT called bipolar junction transistor and PMOSFET called power metal-oxide field-effect transistor. Thus does IGBT process is very high input impedance like PMOSFET and has low on-state power loss as in a BJT. Insulated gate bipolar transistor is totally free from the second breakdown problem present in BJT. All these merits have made it IGBT very popular among in all power electronics engineers. 

Thyristor: The terms thyristor called SCR denotes a family of semiconductor devices used for power control in dc and ac systems. One of the oldest members of the thyristor family called SCR silicon control rectifier (SCR) is the most widely used for the device. 

Terminals : 

IGBT Has three-terminal known as a collector(C), emitter(E), and gate(G) whereas SCR (thyristor) has three terminals known as the gate(G), an anode(A), and the cathode(C).  

Layers : 


IGBT is a semiconductor device with four alternating layers called (P-N-P-N) and they are controlled by a metal-oxide-semiconductor (MOS) gate structure whereas SCR (thyristor) is three-terminal four-layer device.

Junction : 

IGBT has only one PN junction, while SCR (thyristor) consist of three PN junctions.

Application :


IGBT are most commonly used medium power application such as dc and ac motor drive, UPS system, power supplies, relays and contactors, where SCR (Thyristor) is most commonly used to a converter, is used to convert an alternating power into alternating power of different frequency and amplitude. Both device IGBT and SCR are used in high power applications and control currents.

IGBT used for always needs a continuous supply of gate voltage whereas Gate of the SCR (thyristor) only needs a pulse to change into conducting mode.