LH0002CN unity buffer chip?

George H.

We are suppose to have 20 of them coming from someone on Amazon, we'll see how that works out!

Thanks.

Jamie

Geez, you have to watch out for that grey market stuff. I got a bunch of taped OP275s from a gey market dist some years ago. I have a scenario. AD changed their marking with little triangle logos that you could mistake for a pin 1 mark. They clearly were wrong compared to the new (at that time) chamfered side of the SO8 package. My guess is somebody built a boatload of boards with the chips backward, scrapped the boards and then somebody else picked the chips off and resold them on the grey market. About 15 - 20% of the chips burned up immediately when power was applied. One fried a few minutes after apparently working OK at first. When examining ther tapes, the date codes were mixed. Half a dozen chips from one week, then a bunch from a different week. AD assured me this was ABSOLUTELY impossible the way they made the chips. A reel could NEVER have two date codes on it. Looking at the chips, there was NO WAY you could possibly tell they were recycled.

More recently, I had a board that used the obsolete Xilinx 9500 5V CPLD, and had a bunch left with no source for franchised chips. So, I bought a hundred chips from some guy on Ali-Baba, knowing there could be "problems". Well, most of them work! But, a few of them fail to do anything, and can't be programmed. The JTAG port is dead. If the JTAG works, then the chip works completely. Looking closely at them, there is no pin 1 dimple, as all real Xilinx parts have. So, I'm pretty sure these are counterfeit. I don't know if somebody got hold of old masks or somehow actually re-engineered the whole part. But, my guess is ** I'M ** doing the functional testing of the part. Possibly, they are somehow getting scrapped or extra wafers and just dicing and packaging.

So, watch out with any of these non-franchised distributors. They accept returned items with very little control over their history.

Jon