ADS8684: ASD8684 Ref I/O Issue

bertrand rozier

Part Number: ADS8684

Hello,

On my last production batch, I have 3,75 volt on Ref I/O pin instead of 4,096V as expected.

What could be wrong? I can fix it by software to compensate the deviation, but I need to be sure this error is constant & stable

I don't see any issue in my sche!atic ( already work in previous batch with any issue).

Could I received fake component?

Is there anyway to check?

Thank you

Bertrand

over 2 years ago

0 Ryan Andrews over 2 years ago

TI__Guru 66346 points

Hi Bertrand,

Thank you for your post. Can you share the schematic portion showing the ADS8684 and surrounding connections? I'm specifically interested in what else might be loading the pin. Are other supplies measuring correctly?

Regards,

Ryan

0 bertrand rozier over 2 years ago in reply to Ryan Andrews

Prodigy 50 points

Hello,

Here after the schematic. 5VA is ok, 3V3 is OK also.

0 Ryan Andrews over 2 years ago in reply to bertrand rozier

TI__Guru 66346 points

Thanks, Bertrand. The schematic looks correct to me.

What is the voltage measured at the REFCAP pin? Is it the same as REFIO voltage?

If this is still an issue, can you tell us how many ADS8684 devices are affected?

Regards,

Ryan

0 bertrand rozier over 2 years ago in reply to Ryan Andrews

Prodigy 50 points

Same schematic worked for a previous production batch.
Yes REFCAP at similar voltage level than REFIO.

My batch is 20 units only, but I bought 50 in total. All board seems to be affected, even some with 0V.

Regards

Bertrand

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ADS8684: ASD8684 Ref I/O Issue