Post on 06-May-2015
description
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