Help identify SMD components - Page 1
Forum section: electronics / beginners

author: todorp
author_rank: Regular Contributor
timestamp: December 07, 2019, 06:38:33 pm
content: Hello, I would be very grateful to anyone who could tell me what kind of components are those circled in red in the photos (in attachment). The big chip on the first photo is an HDMI tranceiver, while the PCB tracks on the second photo are ethernet. Also if someone recognises the type of these components could you please tell me what their purpouse is and what values are usually used.Thanks in advance,Todp.s. The componets seem to have 4 pads for soldering.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: December 07, 2019, 07:01:25 pm
content: https://www.digikey.ca/product-detail/en/panasonic-electronic-components/EXC-X4CT900X/P19441TR-ND/6109198

author: todorp
author_rank: Regular Contributor
timestamp: December 08, 2019, 10:17:04 am
content: Quote from: Alex Eisenhut on December 07, 2019, 07:01:25 pmThanks a lot! Do you mean this is exactly the component in the photos?!

author: wraper
author_rank: Unknown
timestamp: December 08, 2019, 10:20:45 am
content: Quote from: todorp on December 08, 2019, 10:17:04 amOf course it's not. There are tons of SMD common mode chokes and they don't have any marking.

author: wraper
author_rank: Unknown
timestamp: December 08, 2019, 10:24:58 am
content: What's strange there is no 4th choke besides 3 populated. Isn't it knocked off the board by chance? Photo is not good enough to see pads clear enough to be sure about that.

author: todorp
author_rank: Regular Contributor
timestamp: December 08, 2019, 10:43:34 am
content: Quote from: wraper on December 08, 2019, 10:24:58 amYes, you are right the 4th choke has been knocked off and I am trying to replace it. Knowing the chip is a HDMI 1.3 tranceiver (albeit quite an old one) maybe someone can suggest a typical component used in these cases?Thanks,Tod

author: wraper
author_rank: Unknown
timestamp: December 08, 2019, 10:54:40 am
content: Please measure their size.

author: todorp
author_rank: Regular Contributor
timestamp: December 08, 2019, 01:18:33 pm
content: The measured size (using calliper) is around 2.0mm x 1.2mm. To me this seems to be similar to a 0805 (2012 metric :-)) package...Tod

author: wraper
author_rank: Unknown
timestamp: December 08, 2019, 01:32:49 pm
content: https://lv.farnell.com/w/c/passive-components/filters/common-mode-chokes-filters/smd-common-mode-chokes-filters?impedance=90ohm&common-mode-filter-case=2mm-x-1.25mm-x-0.5mm|2mm-x-1.2mm-x-1.2mm|2mm-x-1.2mm-x-1.3mm|2mm-x-1.2mm-x-1mm|2mm-x-1.3mm-x-1.2mm&sort=P_PRICEThese should do the job. It's better to replace all of them with the same type to ensure there is no signal delay difference between them. Also it's better to choose one which specified to higher frequency or explicitly says in the datasheet to be suitable for HDMI or USB 3.X. Like thishttps://www.we-online.de/katalog/en/pbs/WE-CNSW-HF

author: todorp
author_rank: Regular Contributor
timestamp: December 08, 2019, 01:35:15 pm
content: Quote from: wraper on December 08, 2019, 01:32:49 pmYeah, you are right, I will replace all of them. Thanks a lot for the help. Cheers,Tod

author: wraper
author_rank: Unknown
timestamp: December 08, 2019, 01:42:29 pm
content: For example this one is guaranteed to be finehttps://lv.farnell.com/tdk/acm2012d-900-2p-t00/filter-common-mode-0-3a-90-ohm/dp/2475040Quote