2SJ162/2SK1058 - fake or real?

[seangoesbonk]

I just bought 2 pairs of Hitachi Lateral Mosfets 2SJ162 and 2SK1058... I hope.

As you can tell, I am suspicious. Why? Because of the price, markings, and shape of the 2SK1058.

1) The 2SK1058 is shaped differently than the diagram in the datasheet.

2) The markings are different from a picture I that I saw.(I have only seen the one pair, mind you)

3) The price was too good to be true!

Is it possible? Did I stumble upon the fabled free lunch?

Here's is the pic of the pair I've seen:

[seangoesbonk]

The front:

[seangoesbonk]

The back:

[timc]

I hope they are not fakes, because they look just like
the batch I bought!

I bought mine from a local distributor that I was directed
to from Hitachi, so I would hope they are real.

Regards,
Tim

[timc]

Not sure about the 2SK1058. When I said mine looked the same
I was refering to the first pic (2SJ162 and 2SK1058 in same package).

Regards,
Tim

[ThingyNess]

The one on the right appears to be in a TO-264 case instead of the standard TO-3P case that most of the japanese semi manufacturers use.

I can't see hitachi switching case styles and keeping the same part number, as there are pretty significant differences in the lead spacing between TO-3P/TO-247 and TO-264 if I remember correctly, not to mention the different package outline that could "break" some designs using them.

There are "generic" chinese made clones of some japanese semis, such as the 2sa1302/2sc3281, but they don't have the Toshiba logo on them, and don't really "pretend" to be real devices. The TO-264 packaged device you have there DOES have a real Hitachi logo on it, so it's either a real device (seems unlikely, but you never know), or a fake.

Out of curiosity, did you buy those locally, Sean? I've been meaning to get some and was thinking about hitting pacificsemi up for a few.

One way to check of course would be to crack a complementary pair open and have a look at the dies -- if they're very similar, they hopefully will be real.

However, if they are real, you can be happy that you have at least one in the TO-264 package, as it's superior to the TO-3P in terms of thermal resistance and current handling (larger/thicker leads)

Edit: It's interesting to note that the lettering on the TO-264 packaged one actually looks like the known good ones, and the one in the correct TO-3P package style looks like it has odd lettering compared to the samples you posted above. Weird!

- Rick

[jackinnj]

it doesn't seem that the usual stockists have them in -- check www.findchips.com.

the Vgs(t) of the Hitachi devices is very low -- there's a test you can do yourself to compare it with a regular MOSFET -- take look at the charts in the PDF and you'll see.

Fabled saying at my graduate school alma mater <b>TANSTAFAL</b> -- "There ain't no such thing as a free lunch".

[ashok]

Which PDF ?
Cheers.

[jackinnj]

there's a Vgs vs I(d) graph in the PDF

btw, wherabouts in India?, I am going there again in the winter.

[ashok]

Hi Jackinnj,
I live in South India - in Chennai to be exact.
Have you been to this part of the country ? Want any 'tourism suggestions' ?

I get what you mean about the Vgs. Yes the Hitachi ones have very low Vgs - looks like a bjt base emitter voltage.
I bought some locally for about US$6.5( a pair). I have not tried them out yet. They look quite like the originals that I bought in Hong Kong a long time ago.

Cheers.