ADS7865: layout on the datasheet P26 Figure 37. Optimized Layout Recommendation

Hirotaka Matsumoto

Part Number: ADS7865

Hi all

Would you mind if we ask ADS7865?

<Question>
On the layout on the datasheet P26 Figure 37. Optimized Layout Recommendation, it seems that 22pin(WR) connects to BVDD.
It is mistake between 22pin(WR) and 24pin(BVDD), right?
22 pin don't have to connect to BVDD, right??

Kind regards,

Hirotaka Matsumoto

over 9 years ago

0 Hirotaka Matsumoto over 9 years ago

Guru 27595 points

Hi team

We guess that your team is so busy, however could you give us the reply?

Kind regards,

Hirotaka Matsumoto

0 Abhijeet Godbole over 9 years ago

TI__Expert 5575 points

Hello Hirotaka San

Sorry for delay in answering your query.

Bypass capacitors should have been connected between BVDD and BGND. Thanks for pointing this out. We will get this corrected.

Thanks & Regards

Abhijeet

0 Hirotaka Matsumoto over 9 years ago in reply to Abhijeet Godbole

Guru 27595 points

Abhijeet san

Thank you for your reply!

Bypass capacitors should have been connected between BVDD and BGND
->Just in case, if you have some attention about the layout in case of connection capacitors between BVDD and BGND, could let us know it?
As our imagination, pin22" to BVDD" replace with pin 24, right?

Kind regards,

Hirotaka Matsumoto

0 Abhijeet Godbole over 9 years ago in reply to Hirotaka Matsumoto

TI__Expert 5575 points

Hello Hirotaka san

Some of the general rules to limit injection of noise from external digital circuitry are

1. Place bypass capacitor between BVDD pin and BGND as close to pin as possible.

2. There should not be any vias on trace connecting BVDD/BGND pins to capacitor pads.

Please let me know if you need additional information on this

Thanks & Regards

Abhijeet

0 Hirotaka Matsumoto over 9 years ago in reply to Abhijeet Godbole

Guru 27595 points

Abhijeet san

Thank you for your reply!
OK, we got it!

Kind regards,

Hirotaka Matsumoto

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ADS7865: layout on the datasheet P26 Figure 37. Optimized Layout Recommendation