DCP021515: Problem we have when we use parts from one lot of 50 DCP021515P devices which won’t startup for 20 seconds

Hi Brian,

Thanks for letting us know about this. It sounds like you already have done one half of the A-B-A swap test, so is it possible for you to take the non-working unit and swap to a known working board to confirm the issue follows the IC?

Regards,

Richard 

Richard: I took the non-working 3 parts from the failing board and swapped to the known good board and the startup issue followed to the good board.

Richard: Can you check out why we are having lots of failed parts for parts with date code 95Z3L7H_K? We have had more success with parts with date codes 66Z7S1H_K, and 84Z789H_K.  Can you find out what do these date codes mean and if there are some differences between parts with these date codes?

Hi Brian,

I'm checking in with the internal team, and please be patient for results.

Regards,

Richard

Hi Brian,

Just so that we have more information, can you provide a schematic and layout for review with the input/output operation conditions? Any waveforms is also appreciated.

Regards,

Richard

Richard: Attached are schematic, section of a layout with yellow signal highlighted and some waveforms showing the issue with Ch1 = VBNEG, CH2 = -15V rail

Richard: Shown below are schematic, section of a layout with yellow signal highlighted and some waveforms showing the issue with Ch1 = VBNEG, CH2 = -15V rail.

Hi Brian,

Thanks for providing the waveforms, schematic and layout.

The schematic and layout does not look abnormal. 

Did you purchase the material directly from TI, or from an authorized distributor? Which distributor, in this case?

I'm also adding Youhao to support further requests since there's a change in engineer in charge of E2E for this month.  

Regards,

Richard

Hi Brian,

Since there is no update from you side after more than three weeks, may I assume the issue is resolved and we can close this thread?  You can re-open it by adding a new post.

Thanks,

Youhao

The issue of "What could be the cause of this problem we have when we use parts from one lot of 50 DCP021515P devices which won’t startup for 20 seconds in our circuit which has 3 parts running from the output of one LM337T -15V regulator, but other parts used from different lots startup right away?" has not been resolved yet.

In answer to Richard's question about where we purchased the parts:

We purchased 50 parts from Texas Instruments on 1/10/2023 and 52 parts from Mouser Electronics on 5/20/2022.

Hi Brian,

The devices should perform similarly. It sounds weird that one lot behave completely differently.  Please submit the units for further investigation by following the procedure at the following link.

http://www.ti.com/support-quality/resources/customer-returns.html

Best Regards,

Youhao