ADS54J60: idle channel input before the block is frozen

Kazuhiko Hirano

Part Number: ADS54J60

Hello,

My customer is using ADS54J60 with DC-coupling input.
In the datasheet 9.1.4.1, what does “idle channel input” mean?

What kind of DC input signal should be used for the “idle channel input”?

Or, ACD input should be floating when estimating the internal dc offset?

Best regards,

K.Hirano

over 2 years ago

0 jim s over 2 years ago

TI__Guru* 91947 points

K. Kirano,

This usually means turning off the input to the ADC. If the input cannot be turned off, then remove it if possible. The DC Offset correction is trying to correct for DC offset mismatch between the 4 internal ADC's, so the idea is to have no external DC component present during this calibration.

Regards,

Jim

0 Kazuhiko Hirano over 2 years ago in reply to jim s

TI__Genius 11613 points

Jim

Thank you for your response.

Let me confirm “no external DC component present during this calibration”.
Does this mean “INXP/N are floating”, “INXP/N are biased VCM”, “INXP/N are biased GND”, or something else?

Best regards,

K.Hirano

+1 jim s over 2 years ago in reply to Kazuhiko Hirano

TI__Guru* 91947 points

K. Hirano,

Set the inputs to VCM.

Regards,

Jim

0 Kazuhiko Hirano over 2 years ago in reply to jim s

TI__Genius 11613 points

Jim,

I see, thank you for your clarification.

Best regards,

K.Hirano

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ADS54J60: idle channel input before the block is frozen