THS4031: THS4031IDGNR

Hi Dan,

As you are aware this device was designed using a different technology as the PCN you added highlights. In general they were tested to ensure they operate in a similar manner. Specific to the noise performance. There was no big design change with regard to this spec. Can the customer share additional information for how the device behaves and what is failing. Screenshots of the output signals showing the noise performance difference would be very useful to see if their are other underlying issues. Additionally, a schematic and PCB layout will also be useful to get a better understanding of the circuit.

Best Regards,

Ignacio

Hi Ignacio,

I will forward the information to you as it becomes available to me. Is it possible to purchase parts from your 150mm Dallas fab? We have discovered the noise is not present when using these parts.

Thank you

Hi Dan,

Unfortunately, this will likely not be possible. We have both old and new stock that are equally likely to get delivered to customers so it is hard to confirm exactly what we can source and send. However, I am happy to look over the circuit and offer suggestions to improve the behavior. 

Best Regards,

Ignacio

Mouser has stock available. Here is their contact information: +85259975614. Please contact them privately to estimate and confirm which year's stock you need. Hope this helps.

Hi Ignacio, just to be clear, TI does not offer a specific, order-able part number that would denote the specific fab the parts came from? I am aware of other OEMs that will add an alpha/numeric suffix to an existing part number to denote where it came from. I recognize this is not common, but some manufacturers do this. I'm attaching a snippet of the schematic below, scope shots will follow, the noise is present during steady-state/quiescent operation (no active inputs).

Hi Dan,

Unfortunately, we do not have this option when ordering our devices as we have multiple fabs and assembly sites so the OPN itself does not offer this information. Thank you for providing the schematic. I was hoping you could send a scope shot of the noise difference between the old and new device. I am curious if there is an underlying issue with the switch in the feedback. We often see stability issues with this setup so an image of the signals being seen would be good to get more understanding of what could be happening. 

Additionally, do you see a noise difference between the old and new device when you set the switch to S2B (gain of 1V/V)? 

Best Regards,

Ignacio

Hi Ignacio,

Thank you for the lead. We will investigate, and I will reply back here. One additional question: is there a specific marking on the package that denotes the parts came from the Dallas fab? We are trying to source parts, and as of right now the only way I know how to do this is to sort by date code* (pre-March 2024 per the PCN).

Thank you

Hi Dan,

I was able to ask our team and they believe this would likely be the best way to tell which device it is. The issue is that under certain circumstances depending on where the die is being assembled you could get the same markings potentially if they packaged old and new die so I am not sure if seeing the markings is enough to tell in my opinion. I would potentially consider using the date code like you suggested and looking at the markings as a second option/check. If I receive an update on what other markings or package labels can be considered I will let you know.

Best Regards,

Ignacio