IGBT

Group Name: GA-7

Group Leader: Azfar Rasool 12-EL-04

Group Members:

Musa Ali 12-EL-37

M.Imran 12-EL-30

Saba Nazeer 11-12EL-57

IGBT(Insulated Gate Bipolar Transistor)

What does word stand for…..

Combination of BJT and MOSFET {[(HOW)}

Lab Symbol

Detailed description of symbol

Construction and Basic Structure

Revert the polarities and..

Check!

Changing to simplified circuit…

Working And Operation

Controlling factor: Gate Voltage

Called as voltage-controlled BJT

Input current zero at gate; as insulated

Input is MOSFET characteristics

Output is BJT characteristics

Threshold Voltage

Working And Operation

npnp structure Thyristor

Parasitic transistor and resistence

no effect under normal operation

Max collector current

Parasitic transistor activates

Thus parasitic thyristor activates

Latch up condition dominates

i.e. IGBT will remain on

Cannot controlled by gate voltage

How do IGBT LOOK like….

1RGT10075M12 Made in Italy

5EMK80N

Made in ChinaInternal StructureA Dissectional view of IGBT

• All of the IGBT’s related to any model do have the simplified circuit drawn on it.

Importance & Advantages of IGBT in Electrical & Electronics world

Combine features of MOSFET & BJT under single device

High current & High voltage Switching Applications, provides safe gateway

Low on state voltage drop (MOSFET part) & High on state current density; so smaller chip size & low cost manufacturing & production

Low voltage drop at input gate; so easily controlled compared to thyristors & BJT’s.

High density current conduction provides excellent forward & reverse blocking capabalites.

It can be used in every electronic and electrical circuits where high switch repletion is need.

Applications of IGBT’s in Electrical & Electronics World

Switch Mode Power Supplies (SMPS)

Safe controlling to work with high voltage or high current.

Uninterruptible Power Supplies (UPS)

Old UPS gives audible irritating sound

IGBT use in UPS gives it high dynamic range and low noise.

Ex: China company HOMAGE UPS

Pulse Width Modulation (PWM)

Increase or decrease the pulse width according to requirement and desire

Three Phase Drivers

Switching Characteristics of IGBT’s IGBT Switching Test Time Circuit

Switching Characteristics similar to Power Mosfet

Difference is; tailing collector current due to stored charge in N (negative) Drift region

Tail current increases turn off loss

Also increase the dead time between the two devices in half-bridge circuit

Operates at -15V at gate to switch off

Turn off speed limited of IGBT (How)Lifetime stored charge or minority carriers in N(-ve) drift-regionBase is parasitic PNP transistorNo External means to sweep the minority carriers from N(-ve) drift regionTo improve Switching time N(+ve) buffer layer helps

References:Powered by google imagesAbdus Sattar 1XYS CorporationText book: Electronic Device and Circuits by Floyd

Thank You

Any Queries