12V-5V buck converter layout feedback using TPS54331DR IC - Page 1
Forum section: electronics / general

author: newtekuser
author_rank: Frequent Contributor
timestamp: December 24, 2024, 05:09:16 am
content: 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!

author: daisizhou
author_rank: Super Contributor
timestamp: December 24, 2024, 11:28:54 am
content: https://we.tl/t-RjTRRjgkeHHere is the complete PCB layout, please check it out

author: newtekuser
author_rank: Frequent Contributor
timestamp: December 24, 2024, 06:15:15 pm
content: Quote from: daisizhou on December 24, 2024, 11:28:54 amThanks, but I'd like to get feedback on the layout I attached.

author: daisizhou
author_rank: Super Contributor
timestamp: December 24, 2024, 09:07:32 pm
content: https://www.douyin.com/user/MS4wLjABAAAAsrnydfX_gbCgGmRky_QT9Wb2DWgu3HW4-OZdRTNBeYxiiXZc4KSjrQEkq0Rp1N6v?from_tab_name=main&modal_id=7350684535358590219&vid=7450517367639149834Please watch this video, you will find the answer you want.

author: thm_w
author_rank: Super Contributor
timestamp: December 24, 2024, 09:44:27 pm
content: - 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 shorterI'm sure it will work fine as is, but its a fair departure from the datasheet layout.

author: daisizhou
author_rank: Super Contributor
timestamp: December 24, 2024, 10:32:09 pm
content: Each component is not placed randomly。If you care about quality, I recommend the best layoutIf you want to learn please watch the video carefully, this is the best version I think, no doubt about it.Looks like【artwork】

author: newtekuser
author_rank: Frequent Contributor
timestamp: December 25, 2024, 01:07:13 am
content: Quote from: thm_w on December 24, 2024, 09:44:27 pmThank 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.

author: daisizhou
author_rank: Super Contributor
timestamp: December 25, 2024, 01:48:05 am
content: 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 betterBecause 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.

author: newtekuser
author_rank: Frequent Contributor
timestamp: December 25, 2024, 02:33:37 am
content: Quote from: daisizhou on December 25, 2024, 01:48:05 amThanks 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.

author: daisizhou
author_rank: Super Contributor
timestamp: December 25, 2024, 04:32:05 am
content: 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 themI can only cut some pictures and upload them to you, but there are still many details that may be overlooked

author: Niklas
author_rank: Frequent Contributor
timestamp: December 30, 2024, 10:26:30 am
content: 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.

author: daisizhou
author_rank: Super Contributor
timestamp: December 30, 2024, 11:38:37 am
content: Quote from: Niklas on December 30, 2024, 10:26:30 amIn 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 manufacturerAnd release some open-source layout diagrams*PS*Many DCDC chips produced in China are also good choices. Welcome to choose and use them