LM833: Package marking and date code

Hello Ron,

thank you for information. Z83 is LM833MMX/NOPB. I tried page "Part marking lookup" for searching, but there is no information about the date code. Z83 is not LM833-N, but LM833MMX/NOPB:

Page:

Datasheet:

This should be same silicon as it was for National Semiconductor (the MM versions).

Does the marking 276K mean that 2 = last digit of the year, 7 = the month, 6 and K is not date code? How do you know that is older than 2012? It couldn't be 2002? I'm not sure how long has it been in production.

Thank you for support.

Thank you Ron. We have produced various products incorporating this operational amplifier. However, we've encountered a soldering problem consistently affecting a particular pin on all components. To investigate the possibility of these being counterfeit parts, we aim to trace these products back to their source. Deciphering the Date Code and other markings will be instrumental in this process.

Marvin,

This small device has an abbreviated date code marking. The full information for lot can be found on the reel's box (and on reel). Where did you purchase the op amps and do you still have a reel label?

Generic information here: https://www.ti.com/support-quality/quality-policies-procedures/anti-counterfeit.html

Is that pin in focus on the original picture? Is the issue an open connection? Is the pin physically not connected? 

The LOT number was only available for parts purchased directly from TI.com. But the rest we bought from other sources. The Date Code corresponds to this. According to another supplier, the date should have been 2022/07, which fits with the 276K marking.

The parts with the 276K marking had poor solderability. There was a cold joint. When the part passed the normal test, but after coating it no longer worked properly. The coating had seeped into a small gap and slightly raised the pin, causing a complete disconnection. Problem is not visible on the photo.

Thank you

Marvin,

Here is a lists of approved vendors. https://www.ti.com/ordering-resources/faqs/purchasing-online/authorized-distributors.html

I assume that no other devices on the circuit board are having similar soldering issues. 

In any case, I suggest contacting the vendor to address this issue. Going forward, be sure to always use a vendor from the approved list.

Thank you. Our quality and purchasing department is already solving the problem with the distributor. Other devices on PCB are OK - no soldering issues. I think it is a distributor specific problem. I think it's not problem of TI.