LMZ31506: Layout of LMZ31506

takahiko yokota

Mastermind 7135 points

Part Number: LMZ31506

If I use LMZ31506 under design, what are there any problems?

Should I connect AGND with PGND only 1 layer?

1 layer：signal, LMZ31506

2 layer：GND

3 layer：Power

4 layer：Power

5 layer：GND

6 layer：signal

Best regards,

Yokota

over 7 years ago

0 J Arrigo over 7 years ago

TI__Mastermind 28020 points

The LMZ31506 can operate from 0A to 6A without any issues.

When connecting AGND to PGND, the connection should be made at one point as shown in Fig 43 of the datasheet.

0 takahiko yokota over 7 years ago in reply to J Arrigo

Mastermind 7135 points

My customer consider the following the layout.
The AGND connect to the PGND at one point on surface layer,
the AGND doesn't connect to the PGND on 2 layer.
There are only the PGND on 5 and 6 layer.
Should I set up the AGND on 5 and 6 layer?

1 layer:Signal, LMZ31506
2 layer:AGND and PGND
3 layer:Vin and Vout
4 layer:Other power supply
5 layer:PGND
6 layer:PGND

Best regards,
Yokota

0 J Arrigo over 7 years ago in reply to takahiko yokota

TI__Mastermind 28020 points

The customer's layout is correct. AGND should only be connected to PGND at one point. Since they make the connection on the surface layer, they should not set up AGND on layer layer 5 & 6.

0 takahiko yokota over 7 years ago in reply to J Arrigo

Mastermind 7135 points

Thank you for the answer.

I'm sorry but my understanding is poor.

Could you tell me the reason that they should not set up AGND on layer 5 & 6?

Best regards,

Yokota

0 J Arrigo over 7 years ago in reply to takahiko yokota

TI__Mastermind 28020 points

To avoid ground loops, the AGND should only be connected to PGND at one point. Since your customer is already connecting AGND to PGND on the top layer, it should not be connected again on layer 5 & 6.

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LMZ31506: Layout of LMZ31506