TPS62147: About GND/AGND Layout

mayumi.T

Part Number: TPS62147
Other Parts Discussed in Thread: TPS62148

Hello,

My customer has a aquestion about TPS62147&TPS62148.

Is there a problem with wiring GND and AGND without separating the input side and the output side?
In the Layout example of the data sheet, it is the same.

If it is an application that needs to consider noise, should GND be separated?

When separating, please teach parts to be wired to GND / AGND respectively.

Thank you.

over 7 years ago

0 Chris Glaser over 7 years ago

TI__Guru**** 150610 points

Hi Mayumi-san,

GND and AGND must be shorted to the same net in the design. Does this answer your question?

0 mayumi.T over 7 years ago in reply to Chris Glaser

Expert 1015 points

Hello,Chris-san,

Thank you for your early response. I told the customer.

I got a question again from the customer. Would you please reply.

Qusetion:

Is it better to separate the PGND plane and AGND plane when noise is care?

(For example as in the reference layout of the TPS 568215 datasheet).

Please kindly advise.

Thank you.

Mayumi

0 Chris Glaser over 7 years ago in reply to mayumi.T

TI__Guru**** 150610 points

Hi Mayumi-san,

Yes, it is usually a good practice to connect quiet nodes to an AGND plane/net and the switching/noisy nodes to a PGND plane/net and then connect the 2 at a single point. Anything carrying switching current, such as Cin, Cout, PGND, etc. should connect to PGND. SS, FB, etc. should connect to AGND.

0 mayumi.T over 7 years ago in reply to Chris Glaser

Expert 1015 points

Hello,Chris-san,

Thank you for your frequent answers.
I think your answer is the answer that my customers want!
I will tell my customers.

Thank you.
Mayumi

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TPS62147: About GND/AGND Layout