LM337T/LM317T On Semi fake?

[ace99]

Hello,

I bought on ebay few weeks ago form South Korea a few pcs of LM337T/317T. They re different. LM337T looks like fake one, but I'm not sure, maybe its old part LM337T ONs?
IMG_4442.JPG IMG_4437.JPG IMG_4436.JPG IMG_4439.JPG IMG_4440.JPG IMG_4441.JPG

[homemodder]

There are so many manufacturers of these parts you could pick and choose. To be on the safe side that performance is as stated on datasheets I would rather tend to purchase parts manufactured by well known and reputable companies such as ON.

[ClaveFremen]

Originally Posted by ace99

I bought on ebay few weeks ago form South Korea a few pcs of LM337T/317T. They re different. LM337T looks like fake one, but I'm not sure, maybe its old part LM337T ONs?

they don't seem fake, look at the attached picture.

Those are original ON Semi MC7812 and MC7912, same thin tab.

I've bought them from RS Components, a reputable world reseller.

Copper price is so much higher than in the past that ON reduced tab thickness, that's all.

[jitter]

Originally Posted by ace99

Hello,

I bought on ebay few weeks ago form South Korea a few pcs of LM337T/317T. They re different. LM337T looks like fake one, but I'm not sure, maybe its old part LM337T ONs?
Attachment 251256 Attachment 251257 Attachment 251258 Attachment 251259 Attachment 251260 Attachment 251261

I can't imagine the LM3x7 being faked, real ones are cheap enough not to be interesting for conterfeiters, IMHO.

Don't let the thin tab of the LM337 in your pictures fool you, that's the single gauge case, and they probably are genuine. The style of the case and printing looks exactly like what I'm used to from ON Semi.

Other manufacturers, like ST and Fairchild, are also using single gauge cases (although recent ST LM317s seem to be dual gauge again). Also take a look at this post:My Transistors, original or copy?.

The LM317 in your pics isn't one I recognize as typical ON Semi, but that doesn't neccessarily mean it's fake...