Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Class D Switching Power Amplifiers and Power D/A conversion

Substitute MOSFETS
Substitute MOSFETS
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 8th November 2009, 05:02 PM   #1
DrWoofer.com is offline DrWoofer.com  Greece
diyAudio Member
Join Date: Jul 2007
Default Substitute MOSFETS

I have a damaged car amplifier that has 12 IRFZ44V in power supply section that need replacement.I have searched and couldn't find this version in Greece or in Europe.I could only find IRFZ44 (without V).It has the same VDSS=60V but different RDS(ON)=28mOhm vs 16.5mOhm and ID=50A vs 55A.

Can i substitute one type for the other?I don't care about max performance.I just need the amp to be functional.If i change something in circuit can i make IRFZ44 work with lower load to be on the safe side?



Do you know any European based MOSFET supplier but not asking to buy large quantities?

DIGIKEY told me they send from USA only and i will have to pay customs.
  Reply With Quote
Old 8th November 2009, 06:20 PM   #2
event horizon is offline event horizon  England
diyAudio Member
event horizon's Avatar
Join Date: Feb 2008
Location: East Midlands, England
In my opinion you could simply swap the lot with no problems The switching times for the same current look very similar the the same "R Gen" & at the same current. As there is no way that the Mosfets will actually see 50Amps accross them each then the actual RDS on will be lower at a lower current.

All that'd happen is you'd have a SMPS with a slight bit more RDS on switching losses, however as the IRFZ44 has a lower input capacitance you may well find that as they will switch on & off slightly faster (with an inductive load - the transformer) that this will actually have less losses in the switching phase & tend to even things out

I doubt you'd need to alter any snubber networks or anything else for that matter. If you feel like playing safe just make sure you don't drive the amplifiers into the lowest loudspeaker impedances that it can handle at full volume..


You might like to ask how many there are available.

Hope this helps
"Never let your morals prevent you from doing what is right!" Salvor Hardin

Last edited by event horizon; 8th November 2009 at 06:29 PM. Reason: added links
  Reply With Quote
Old 8th November 2009, 11:21 PM   #3
darkfenriz is offline darkfenriz  Poland
diyAudio Member
darkfenriz's Avatar
Join Date: Jun 2004
Location: Warsaw
The 'V' version has a lot less Qrr, which means better efficiency and less EMI.
You may try polish distributor I like:
Elementy i podzespoły części elektroniczne - TME - Electronic Components
if they don't count too much for a delivery or try to find something with similar parameters. Charges (Qgtot, Qgd, Qrr) are a lot more important then for example Rds-on.

Something like IRFB3806 could be some real upgrade

Last edited by darkfenriz; 8th November 2009 at 11:25 PM.
  Reply With Quote
Old 10th November 2009, 10:46 PM   #4
fumigamt is offline fumigamt  Brazil
diyAudio Member
Join Date: May 2008
substitute of IRFZ44 , you can take FQP 50N06 , or TQP 50N06, only diferent have diferent manufatored , one is Fairchild , and other is ST eletronics.

55N06, works very great too.. i dont use more IRFZ44 , i use only 55N06.

so... if will be 2 or 3 mosfets in parallel , you can change for only one of IRF1404 ,
Igs = 196A , about 55 of the other fets relateds above.

i hope i have helped.
  Reply With Quote
Old 21st November 2009, 08:24 PM   #5
odnaizutra is offline odnaizutra  Guyana
diyAudio Member
Join Date: Jan 2007
irf3805.irf3806,ifrz46,irfz48, stp55nf06 are ok.
  Reply With Quote
Old 21st November 2009, 08:55 PM   #6
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
nigelwright7557's Avatar
Join Date: Apr 2008
Location: Carlisle, England
Originally Posted by odnaizutra View Post
irf3805.irf3806,ifrz46,irfz48, stp55nf06 are ok.
You dont say why they have blown.

12 is a lot to replace.
I would just replace one pair and try that before committing the full 12.
Just dont turn it up with one pair !
PCBCAD51 pcb design software. 2018 version out now with lower prices >> http://www.murtonpikesystems.co.uk
  Reply With Quote


Substitute MOSFETSHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Substitute Lateral Mosfets joensd Parts 33 21st December 2008 01:57 PM
n/p Mosfets vs depletion mod mosfets marcello7x Car Audio 6 4th October 2006 05:01 AM
substitute of the OP SSM-2015 Marcelo Solid State 3 27th January 2003 04:31 PM
tr substitute dexter Solid State 5 29th April 2001 02:53 PM

New To Site? Need Help?

All times are GMT. The time now is 10:18 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio