ADC power reference and sources on AM335x

K Md Feroz Irfan

Hi Champs!

If we are supplying VDDA_ADC with 1.8V do we have to connect any power to VREFN & VREFP pins. Can we connect these pins to ground and use internal reference with VDDA_ADC supply.

Regards
Feroz

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Feroz,

You can use the internal reference, which is taken from VDDA_ADC. No need to connect external reference pins to ground.

0 Justin Thomas over 11 years ago in reply to Biser Gatchev-XID

Prodigy 100 points

Hi,

Thanks for your reply.

In datasheet of DRA6xx (pg 89/112), it is mentioned "VREFP and VREFN must be tied to ground if the internal voltage reference is used."

So what to do with VREFA and VREFN pins then?

Thanks

Justin

0 Biser Gatchev-XID over 11 years ago in reply to Justin Thomas

TI__Guru**** 393215 points

We are talking about AM335X on this thread.

0 K Md Feroz Irfan over 11 years ago in reply to Biser Gatchev-XID

TI__Expert 7225 points

Hi Biser,

AM335x has a autoqual equivalent called DRA60/1x. So the question applies to the AM335x as well.....

Can you please review and advise here?

Best Regards

Feroz

0 Biser Gatchev-XID over 11 years ago in reply to K Md Feroz Irfan

TI__Guru**** 393215 points

OK, yes it's true VREFP and VREFN must be tied to GND if internal reference is used. I had missed Note 1 below Table 3-17 in the AM335X Datasheet Rev. F.

0 peaves over 11 years ago in reply to Biser Gatchev-XID

TI__Guru 63125 points

You should read Advisory 1.0.32 in the AM335x Silicon Errata.

Regards,
Paul

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ADC power reference and sources on AM335x