ADC08DJ3200: ADC input tracing

Emir Karamehmedovic

Part Number: ADC08DJ3200

Dear TI, I am tracing a board with ADC08DJ3200. It seems to me that in the ADC's EVM, the differential inputs of channel A and B are traced as 50 Ohm single ended traces (first image). In my layout, is it better to trace these as 100 Ohm diff. pair (second image)? If you have other general suggestions concerning the traces, please do share your thoughts.

over 1 year ago

0 Rob Reeder over 1 year ago

TI__Mastermind 41940 points

Hi Emir,

50ohm traces for the analog inputs is fine in your layout. Typically these traces are not tightly coupled.

Are you using a balun or amplifier to couple to the analog inputs?

Thanks,

Rob

+1 Emir Karamehmedovic over 1 year ago

Prodigy 10 points

Hi Rob!

You recommend to change to 50 Ohm SE traces as in the EVM. All right.

I am not using a balun, the ADC has differential inputs, so my SMA+ and SMA- are connected to ADCs +/- analog inputs. I can amplify the diff. signal on the sender side, so there is no need for an amplifier on the ADC board.

0 Rob Reeder over 1 year ago in reply to Emir Karamehmedovic

TI__Mastermind 41940 points

Hi Emir,

Thank you for the information, so 50ohm traces for you will be just fine.

Regards,

Rob

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ADC08DJ3200: ADC input tracing