is this a genuine IR part ? - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: February 28, 2013, 10:12:41 am
content: I am after some parts in china and I have a very good price (too good to be true?) from a guy so I asked for a photo of the part. I'm not sure that is the IR logo, it does not match the one on their website or the one on parts I already have. Are manufacturers consistent with their branding of parts ?

author: houdini
author_rank: Regular Contributor
timestamp: February 28, 2013, 10:32:32 am
content: likely not. But if it can match the specs does it really matter? And does it match the specs?

author: Simon
author_rank: Unknown
timestamp: February 28, 2013, 10:33:36 am
content: likely not what ? do YOU know how to verify every spec of a mosfet ?

author: TerminalJack505
author_rank: Super Contributor
timestamp: February 28, 2013, 10:41:45 am
content: If you squint it looks like the symbol inthe datasheetand their homepage. (A diode in a circle.)

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2013, 10:44:12 am
content: Simon, I have the exact same part no, yes, they're common jelly bean mosfet and cheap, bought a grab back of them years ago at late 90s. For sure mine are genuine and used it a lot and none have failed yet.If I have time later today, I will take a close up shot and post it here.

author: amyk
author_rank: Super Contributor
timestamp: February 28, 2013, 11:50:08 am
content: It's definitely the IR logo but odd that it's degraded-looking compared to the other markings.

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2013, 03:59:22 pm
content: Although I'm not an expert on how to tell if its genuine or fake, looks like that metal tab is grainy sand blasted, and also thru the mounting hole at the metal tab, usually you can see the copper, not in that photo.Took shots of my IRF4905 instead, sorry, couldn't find my IRF9540, must be hidden somewhere and I'm absolute sure both physically looks identical. The metal tab is mirror finished, just look at the screwdriver's reflection.Attached photos below.

author: Simon
author_rank: Unknown
timestamp: February 28, 2013, 04:06:59 pm
content: Yes there seem to be polished off tabs and dull tabs and i have received the same from the same supplier. Are all tabs supposed to be aluminium ?

author: Simon
author_rank: Unknown
timestamp: February 28, 2013, 04:08:32 pm
content: I had a bunch of 5V regs that were duff, some outputted 1V ! so yes shit does happen

author: Chet T16
author_rank: Frequent Contributor
timestamp: February 28, 2013, 04:13:12 pm
content: *checks regs bought from Simon on ebay*

author: BravoV
author_rank: Super Contributor
timestamp: February 28, 2013, 04:17:28 pm
content: Quote from: Simon on February 28, 2013, 04:06:59 pmWhole aluminium tab ?Definitely fake, especially at "power" mosfet.

author: Simon
author_rank: Unknown
timestamp: February 28, 2013, 04:21:41 pm
content: Quote from: Chet T16 on February 28, 2013, 04:13:12 pmI have good ones now if you got any at the time you'd have found out as soon as you tried to use them and told me and I'd have replaced. The make was WS beware guys. I now stock ST now so no problems.

author: Kremmen
author_rank: Super Contributor
timestamp: February 28, 2013, 04:22:45 pm
content: Quote from: BravoV on February 28, 2013, 04:17:28 pmNaah, it won't be aluminium. That is a matte tin finish, perfectly legit. There will be copper underneath the tin. If in doubt, swipe with a file and you will see.I checked some IR known genuine devices and they are similar, although the markings on mine more closely match those shown in the datasheet TerminalJack linked.

author: Simon
author_rank: Unknown
timestamp: February 28, 2013, 04:36:00 pm
content: I have IRL8113's from Farnell that look like that so I'm not too concerned

author: SeanB
author_rank: Super Contributor
timestamp: February 28, 2013, 06:20:13 pm
content: Easiest test is to just bias them to a voltage somewhere where they are barely turned on and see the on resistance changes down in accordance to the datasheet till it reaches the lowest level at around 15V on the gate.

author: Simon
author_rank: Unknown
timestamp: February 28, 2013, 06:35:15 pm
content: Yea, I was thinking something like that, you could test current capacity to the limit and be able to measure the Rdson too.

author: Slothie
author_rank: Regular Contributor
timestamp: February 28, 2013, 10:45:50 pm
content: Bravo's "helping hand" croc clip has seen some life!