ADS7028: ADS7028

Maxim Pakman

Part Number: ADS7028

Hi,

We have in the system ADC for reading our system analog indications: ADS7028IRTER.

In the last batch of production we started to experience one strange problem: some ADCs has a cold start problem at -20deg and lower. ADC receives input from SPI same way as it used to work but there is no transmitting back at SPI. If there is no DC reset till approach of cold, there is no problem to communicate with the part. It happens in small percentage of cards but it’s still worrying as we don’t understand why it happens. Only solution that we have found is replacement of a part. Our design is exactly by datasheet.

Are you familiar maybe with such issues in these parts? What is the additional information you need in order to investigate the root cause of this problem?

Thanks,

Maxim.

over 1 year ago

0 Tom Hendrick over 1 year ago

TI__Guru**** 180901 points

Hi Maxim,

Can I ask you how long your board has been in production? Has there been any recent changes to your schematic/layout? Any change in PCB vendor or assembly shop?

0 Maxim Pakman over 1 year ago in reply to Tom Hendrick

Prodigy 40 points

Hi Tom, thank you for fast response!

Board is in production for a year. There were some small changes in design but at RF side, not at analog/digital side. Generally we work with 2 PCB vendors but both of them were checked by us and approved. Assembly house is the same for many years already.

Thanks.

0 Tom Hendrick over 1 year ago in reply to Maxim Pakman

TI__Guru**** 180901 points

Hi Maxim,

Can you please provide a picture of the top side package marking?

0 Maxim Pakman over 1 year ago in reply to Tom Hendrick

Prodigy 40 points

Hi Tom, attached. Thanks.

0 Tom Hendrick over 1 year ago in reply to Maxim Pakman

TI__Guru**** 180901 points

Thank you Maxim,

The device in the picture appears to be from May of 2021 (the first two numbers '15' are date code YM). Do you have any details on the previous build as far as when/where you purchased the parts? I'll query our quality database and see if there was any reported issues with this specific lot trace code.

0 Maxim Pakman over 1 year ago in reply to Tom Hendrick

Prodigy 40 points

Hi Tom, I took another one from much older build and it has exactly the same date code. It seems that whole quantity was bought before the first build.

Does this part have any special requirements for storage conditions? I see in datasheet that it doesn't have problem with moisture.