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Electronics => PCB/EDA/CAD => Topic started by: newtekuser on December 24, 2024, 05:09:16 am

Title: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: newtekuser on December 24, 2024, 05:09:16 am
Using a TPS54331DR as switching IC for a 12V-5V buck converter and need some feedback on the layout. I used the sample layout suggested in the TPS datasheet with some small adjustments.

The stack-up is 4 layer (SIG, GND, PWR, GND).

Attached are the schematic and PCB layout. Thanks in advance!
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: daisizhou on December 24, 2024, 11:28:54 am
https://we.tl/t-RjTRRjgkeH
Here is the complete PCB layout, please check it out
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: newtekuser on December 24, 2024, 06:15:15 pm
https://we.tl/t-RjTRRjgkeH
Here is the complete PCB layout, please check it out

Thanks, but I'd like to get feedback on the layout I attached.
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: daisizhou on December 24, 2024, 09:07:32 pm
https://www.douyin.com/user/MS4wLjABAAAAsrnydfX_gbCgGmRky_QT9Wb2DWgu3HW4-OZdRTNBeYxiiXZc4KSjrQEkq0Rp1N6v?from_tab_name=main&modal_id=7350684535358590219&vid=7450517367639149834 (https://www.douyin.com/user/MS4wLjABAAAAsrnydfX_gbCgGmRky_QT9Wb2DWgu3HW4-OZdRTNBeYxiiXZc4KSjrQEkq0Rp1N6v?from_tab_name=main&modal_id=7350684535358590219&vid=7450517367639149834)

Please watch this video, you will find the answer you want.
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: thm_w on December 24, 2024, 09:44:27 pm
- You don't have the topside ground which they mention in the datasheet.
- D5 should have topside ground or more vias.
- C23 and C27 can move closer to D5
- Feedback trace can be a bit shorter

I'm sure it will work fine as is, but its a fair departure from the datasheet layout.
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: daisizhou on December 24, 2024, 10:32:09 pm
Each component is not placed randomly。
If you care about quality, I recommend the best layout


If you want to learn please watch the video carefully, this is the best version I think, no doubt about it.

Looks like【artwork】
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: newtekuser on December 25, 2024, 01:07:13 am
- You don't have the topside ground which they mention in the datasheet.
- D5 should have topside ground or more vias.
- C23 and C27 can move closer to D5
- Feedback trace can be a bit shorter

I'm sure it will work fine as is, but its a fair departure from the datasheet layout.

Thank you very much for the feedback! I opted to not pour GND on top and make room for the bootstrap trace because I didn't want to route it on either the GND or PWR plane and break them. The trace is pretty short though so might be worth the tradeoff.
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: daisizhou on December 25, 2024, 01:48:05 am
The principle that needs to be pursued in layout is:The smaller the high-frequency current area, the better,The closer the capacitor input is to the voltage input pin and GND, the better

Because from the layout analysis, there are "U" type layout or "I" type layout,And the heat dissipation part.
This is the art of compromise, so it is difficult to describe in words. I hope you can understand what is introduced in the video.
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: newtekuser on December 25, 2024, 02:33:37 am
The principle that needs to be pursued in layout is:The smaller the high-frequency current area, the better,The closer the capacitor input is to the voltage input pin and GND, the better

Because from the layout analysis, there are "U" type layout or "I" type layout,And the heat dissipation part.
This is the art of compromise, so it is difficult to describe in words. I hope you can understand what is introduced in the video.

Thanks for the attachment! Unfortunately I can't watch the video as I'm not able to navigate that website in Chinese, but I get the gist. Out of curiosity, what stack-up does it take to reach this level of cleanliness? Is it a 4-6 layer board or more?
I am aware that besides experience, some of it is art as I was able to move around some components and got it a lot closer to the example.
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: Simmed on December 25, 2024, 02:49:07 am
what stack-up does it take to reach this level of cleanliness? Is it a 4-6 layer board or more?
I am aware that besides experience, some of it is art as I was able to move around some components and got it a lot closer to the example.

it is the way you lay it out
look at D5 / L4
if you can rotate it 90degree CCW and bring it down to near C25
C16 to R20 could be brought closer to C26
the top 1/3 of the PCB could then be potentially empty
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: daisizhou on December 25, 2024, 04:32:05 am
Can't you browse videos?
Can't understand the Chinese description or can't browse the video?

Because many details need to be introduced in the video, it's really regrettable if you can't browse them

I can only cut some pictures and upload them to you, but there are still many details that may be overlooked
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: Niklas on December 30, 2024, 10:26:30 am
I tried to watch the video, but it does not play. Might be that it is area restricted and only works in China. No error message, just something red and then it continues to another random video.
Title: Re: 12V-5V buck converter layout feedback using TPS54331DR IC
Post by: daisizhou on December 30, 2024, 11:38:37 am
I tried to watch the video, but it does not play. Might be that it is area restricted and only works in China. No error message, just something red and then it continues to another random video.

In the video, the professor mainly talks about the precautions for DCDC power supply layout.And the defects that appear in the layout of the manual published by the manufacturer
And release some open-source layout diagrams

*PS*Many DCDC chips produced in China are also good choices. Welcome to choose and use them