[ST-LINK/V2 ISOL] schematic reverse engineering - Page 1
Forum section: electronics / general

author: Mikeyzy
author_rank: Newbie
timestamp: December 16, 2022, 05:52:56 pm
content: I've been searching online about the "ST-Link V2ISOL"'s schematics and seems like nobody has done the work for it. So I decided to do some probing on the board.Here is my result, some components are ignored such as TVS diode and bypass caps.If anyone else got a "ST-Link V2 ISOL", feel free to help completing the schematic. Peer review is always nice.Still haven't quite figure out how the isolation work on some lines exactly.

author: pcprogrammer
author_rank: Super Contributor
timestamp: December 16, 2022, 05:56:45 pm
content: Hi Mikeyzy,welcome to the forum and thanks for doing this work, but it might help when you actually attach the schematic.

author: Mikeyzy
author_rank: Newbie
timestamp: December 16, 2022, 06:04:59 pm
content: Some how the attachments didn't go through.I'll try again.

author: pcprogrammer
author_rank: Super Contributor
timestamp: December 16, 2022, 06:38:03 pm
content: I looked at the schematic and with the labels and the not inline placing of the components it is hard to read.An improvement would be to rotate the isolators and use wires to connect them to the other components instead of the net labels. Place the MCU with the USB connector at the left and work the signals to the right with the jtag connector on the right end of the sheet.You can use text to label the signals next to the wires.This exercise might even clear thing up for yourself to get a better understanding of what is doing what.

author: Mikeyzy
author_rank: Newbie
timestamp: December 16, 2022, 07:48:29 pm
content: The schematic was draw so the component positioning resembles how it's located on the PCB, for probing and mapping purpose. Unfortunately eagle being the way it is, there is no way to do directional signal label/tunnel.

author: pcprogrammer
author_rank: Super Contributor
timestamp: December 16, 2022, 07:55:04 pm
content: Can you post pictures of the PCB, both back and front. Would be nice to see what matches the schematic.

author: Mikeyzy
author_rank: Newbie
timestamp: December 16, 2022, 08:33:03 pm
content: files are compressed so they fit the max size.

author: Mikeyzy
author_rank: Newbie
timestamp: December 19, 2022, 04:21:29 pm
content: somehow when I upload attachment, some of them doesn't go through.

author: DavidAlfa
author_rank: Super Contributor
timestamp: December 19, 2022, 05:48:56 pm
content: Really? The couldn't use a smaller crystal?

author: pcprogrammer
author_rank: Super Contributor
timestamp: December 19, 2022, 07:28:07 pm
content: Quote from: Mikeyzy on December 19, 2022, 04:21:29 pmRecently the uploading system has been updated and that broke it. Don't use the drag and drop feature and skip the first attachment option. Click the "more attachments" option and use the new one(s) to select your file(s).Also keep the default End-of-post expandable thumbnail option selected. The rest does not work as intended.Thanks for the photos.Can you identify the big part near the USB connection? Is it a Burr and Brown device?

author: wek
author_rank: Frequent Contributor
timestamp: December 19, 2022, 09:00:11 pm
content: It's a DC/DC converter providing power to the isolated side.JW

author: Mikeyzy
author_rank: Newbie
timestamp: December 20, 2022, 07:15:09 pm
content: the big dip smd part is a expensive TI isolated votage regulator/PS. power section isn't as important since it is easy to figure out. the main concern is on the logic isolation side.