AM3352: Schematic checklist for ADC

Kz777

Expert 7895 points

Part Number: AM3352

Hi Champs,

We are working Pre-work for schematic review

We are checking a schematic check sheet and errata information

＜Pre-check sheet＞

http://processors.wiki.ti.com/index.php/AM335x_Schematic_Checklist

＜Eratta ＞

http://www.ti.com/lit/er/sprz360i/sprz360i.pdf

We don’t use ADC

Pre check sheet mention,

、

If ADC is not used...

Connect all TSC_ADC terminals (VREFP, VREFN, AIN[7:0], VDDA_ADC, and VSSA_ADC) to same ground as all VSS terminals.

Errata mentioned ADC topic at Advisory 1.0.32

If customer don’t use ADC, they have to follow only check list non ADC case comment and can they ignore this Advisory1.0.32 Errata item?

over 7 years ago

0 Kz777 over 7 years ago

TI__Expert 7895 points

Sorry, you may not understand my question.
Actually, in case of "Non use ADC" , schematic check sheet said, Connect all TSC_ADC terminals to grand as same as all VSS terminal.
However, according to errata Advisory 1.0.32, it mention some "TSC_ADC AIN terminals not used" work around.
This work around mention "The preferred option is to have each unused AIN terminal connected to VSSA_ADC
through a 500-Ω resistor. Another option would be to leave the unused AIN terminals
open-circuit without any PCB traces connected to these terminals."

In this case, we should follow only schematic check sheet action. So, we can ignore this Advisory 1.0.32 action.
Is my understanding a correct ?

Regards,
Kz777

0 peaves over 7 years ago in reply to Kz777

TI__Guru 63875 points

The recommendation provided in the errata advisory assumes some of the ADC inputs are used and describes how to connect the unused inputs.

Connecting all of the ADC terminals to VSS is correct when the ADC is not used.

Regards,
Paul

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AM3352: Schematic checklist for ADC