Attiny261 AVCC

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Hi,

I am looking at the attiny261.

In the latest datasheet I could find on the atmel website, Rev2588a -10/6.

-There is a Pin labeled AVCC.
-No mention in the datsheet about hooking up an inductor and cap to the AVCC pin for noise reduction in the ADC section.
-On page 143, Fig 19-1, "ADC Block Schematic", it does not list AVCC as an input, instead it shows VCC
-On Page 3, Fig 2-1, "Block Diagram", it shows AVCC as input to the ADC.

I am used to the atmega168/88/48, and I know that for accurate ADC samples you need to hook up an inductor and cap to AVCC. The Attiny261 datasheet seems to have conflicting information as to the role of AVCC, what purpose does it really serve and if I decouple the pin with an inductor and cap will it reduce sample noise?

Regards,

Alan To

[CLIFF: I merged the three identical threads you started and deleted two copies of the OP - I assume it was an accident with an unresponsive [submit] button but if this happens again [X] the additional copies or contact a moderator]

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Quote:
what purpose does it really serve

It powers the ADC circuitry (and the port pins involved, even if the ADC is not in use).
Quote:
if I decouple the pin with an inductor and cap will it reduce sample noise?

You will want to decouple with a cap in any case, and the inductor will probably help as well.

Regards,
Steve A.

The Board helps those that help themselves.

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What's with the 3 posts Alan? :) Are you in a hurry or something...

[CLIFF: see above]

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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Edit: Original answer deleted, because OP posted the same question three times:

https://www.avrfreaks.net/index.p...

https://www.avrfreaks.net/index.p...

https://www.avrfreaks.net/index.p...

[CLIFF: see above]

Stealing Proteus doesn't make you an engineer.

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- Analog VCC - power supply for A/D
- if u want accurate A/D, u need good filtration of power supply... and every digital circuits, generate whole spectrum of noise... so its reccomended split analog and digital part with filter..
- it could be little mistake... i suppose its AVCC
- its shown as input of AD because it is input of AD... its power supply input...

Computers don't make errors - What they do they do on purpose.

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Warning, OP posted the same question three times:

https://www.avrfreaks.net/index.p...

https://www.avrfreaks.net/index.p...

https://www.avrfreaks.net/index.p...

[CLIFF: see above]

Stealing Proteus doesn't make you an engineer.

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Sorry about the multiple posts, it was not my intention, I hit the refresh a few time too many.

REgards,

Alan To

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Another thread for you to delete, Cliff: https://www.avrfreaks.net/index.p...

toalan: As long as no-one else posts to a thread you've created you can delete it. So if you spot it yourself in time you can undo your mistakes. In the forum index page there is a link top right to "View my posts" which will help you spot the mistakes.

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