Author Topic: IGBT vs MOSFET  (Read 430 times)

0 Members and 1 Guest are viewing this topic.

Offline lighthunter

  • Full Member
  • ***
  • Posts: 162
  • Karma: +8/-0
IGBT vs MOSFET
« on: October 02, 2016, 03:50:19 PM »
Whenever I am trying to put together a circuit I like to choose the most efficient component available. Traditionally, (as if it even applies to electronics) mosfets are chosen for low voltage switching applications and IGBT's are used for the high voltage applications.  Mosfets are good at mimicking a perfect switch when on with their generally low rds on characteristics (some wires have trouble conducting as well as mosfets)  IGBTs on the other hand usually have a minimum of 1.5 to 2.5v across their load current terminals when they are on.

When switching high voltage (above 200) Fets generally have been very expensive and just arent as durable. IGBT's have a fet on their input control so they can be driven with similar circuitry
as a fet but they use a bipolar junction transistor for the current carrier. These have been much better at high voltage durability and when working with high voltage who cares if you lose a couple volts across collector to emitter when on.

Recently i needed a switch for switching DC solar array of 285v under load. This is a stressful place for a switch, ( dont think so? Try it using a relay) second thought please dont.
it could cause a fire.  I thought i would just check if there was a mosfet that could.
outperform an igbt in that application. Sure enough i ran across an infineon ipp50r140 which sports a 500v rating and max drain current of 23amps and rds on of .143ohms.

Parallel a couple of those as a switch in a 10 amp circuit and you have only 7 watts of power loss wich compares to the usage of a relay coil. Most igbts in that application would have around a 20w price tag to do the job. Maybe these higher voltage mosfets with low rds have been around for a while now but i havent seen them. I ordered 10 at $3.64 each hopefully the smoke stays inside. ;D

Regards, LH
LH

Offline eraser3000

  • Full Member
  • ***
  • Posts: 60
  • Karma: +2/-0
Re: IGBT vs MOSFET
« Reply #1 on: October 02, 2016, 09:52:09 PM »
Thanks for sharing.

I just bought some of these a few weeks ago: http://www.infineon.com/dgdl/IKW40N120T2_2_4.pdf?fileId=db3a304412b407950112b426d87b3ad5

Specs say they'll switch 40 amps at 1200V.  Maybe you could use just one of them for your application?

Any thoughts on this unit?  They cost me 7 something each.

Offline lighthunter

  • Full Member
  • ***
  • Posts: 162
  • Karma: +8/-0
Re: IGBT vs MOSFET
« Reply #2 on: October 03, 2016, 09:45:27 PM »
For some reason i cant open the link. Can you post the part number?
Those are definately some kick tail specs.

LH
LH

Offline eraser3000

  • Full Member
  • ***
  • Posts: 60
  • Karma: +2/-0
Re: IGBT vs MOSFET
« Reply #3 on: October 03, 2016, 11:57:17 PM »
IKW40N120T2

Offline lighthunter

  • Full Member
  • ***
  • Posts: 162
  • Karma: +8/-0
Re: IGBT vs MOSFET
« Reply #4 on: October 04, 2016, 04:09:25 PM »
Data sheet says its an igbt with VCE saturation 1.75v at 25C,   10Amps x1.75v = 17.5 w power dissipation. Not bad, thanks but I will take the 7 watt dissipation of the two mosfets for $3.64 ea. since i wont need more than 450v rating.
Will let you know if it works out.

LH
LH