ADC108S022

ryuji asano

Other Parts Discussed in Thread: ADC108S022

Hello, I'm Disty at Japan area. I have 2 question. Please give me the information. ADC108S022 is under consideration. Please show in Figure1 of atached file. My customer is trying to use separate VD and VA power supply. ①Do I have a probrem with this power system of the atached file? (AD_REF：+5V) ②If we have no problem, How many current of VA？ (IA+ID is written Page4 of DataSheet.) Please give me the anser. Best regards.

over 10 years ago

0 Tom Domanski24 over 10 years ago

TI__Expert 3135 points

Hello Asano-san,

I don't the the attachement you are mentioning. But as far as your question is concerned:

You can safely assume that out of the total IA+ID over 80% is due to IA. By the way IA varies a lot as the conversion algorithm progresses. The peak IA is at the moment when the LSB is being resolved - around 14th clock cycle after the falling edge of CS\.

Also, in the application the VD should not come up before VA.

Hope this helps.

Sincerely,

tom

0 ryuji asano over 10 years ago in reply to Tom Domanski24

Intellectual 800 points

Tom-san

Thank you for your help and kindness!!
I was helpful to you. Thank you very much.

I'm sorry. this is the attached file.

Do I have a probrem with this power system of the attached file? (AD_REF：+5V)

Best regards.

0 Tom Domanski24 over 10 years ago in reply to ryuji asano

TI__Expert 3135 points

hi Ryuji,

This power solution looks good to me. Just make sure VD does not power up before VA.

Sincerely,

tom

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ADC108S022