How find datasheet, characteristics and replacement for Bux tvs diode?

[Andriy M]

Posted on December 29, 2016 at 15:48

I ask about one 12v tvs-diode of ST-electronics manufacture - Bux c543. It was found on sp0812n samgung 80 gb hdd

and was soldered through due to overvoltage from psu. Now I need to relace it, but I cannot find any info in the internet on bux series tvs (just the 543- is date marking).

So I want to ask for what another tvs I could replace, could it be any 12v tvs or similar ones? Can you provide any technical characteristics of bux c543 type tvs?

For example data-sheet?

What is critical electrical characteristics of it?

On the internet forum I was proposed to use SMBJ12A diode,

is it appropriate replacement. My master after unsoldering defect bux c543

replaced it temporarily for M545 16a -- could it work temporarily?

[Benoit RENARD]

Posted on January 03, 2017 at 09:15

Hello Andriy,

I ringing the right personn to answer you,

Hoping you obtain your answer soon,

Benoit

[Jean-Michel SIMONNET_O]

Posted on January 03, 2017 at 14:52

Hello Andriy,

The SMBJ12A marking code on package

is BUE. I suppose there is an error with BUX above.

So, here is the ST web address  SMBJxx datasheet:

http://www.st.com/content/st_com/en/products/protection-devices/eos-10-1000-microsecond-surge-protection/600w-tvs/smbj.html

 

After downloading the datasheet, you will have SMBJ12A electrical parameters.

Best regards

Jean-Michel

[Andriy M]

Posted on January 04, 2017 at 16:07

Thank you for you post.  Indeed I do not think that it is ommision

in marking BUX instead BUE -- If you would type 'bux tvs' to google search you

would get enough results (f.e.

https://community.wd.com/t/hdd-tvs-diode-faq/14692

 

), incomparably to 'bue tvs'. So I need to have at least approximate datasheet on BUX-es, as it seems is

widespread hd production of ST. So my question related for BUX data, or any other 12 v tvs, but not SMBJ12A datasheet, which is evident and not difficult to find on the net.

So I would be glad to get additional data on BUX marking or valid raplacement for it?

For example is BUX, as it seems common for 12 v transil identical to SMBJ12A for soldering for samsung HD -- could not

it lead to some misconduct of such tvs or damage of HD during next ovelvoltage?

[Jean-Michel SIMONNET_O]

Posted on January 06, 2017 at 10:40

Hello Andriy,

We don't find any information with BUX marking code for TVS (ST or compet). So, for us, it's a mistake.

If you want to reinforce the TVS robustness, we advice to use higher power capability: SMCJ12A (1500W) instead of SMBJ12A (600W).

Best regards

Jean-Michel

[Andriy M]

Posted on January 06, 2017 at 14:38

If you would see from the link on WD forum you would see such sentence:

'

Some common marking codes for

12V

diodes are

LE, LEM, LEK, BUX, KVP, 13L

.'. It is some kind of semi-official reference. There is a lot of google references for it at specific electronic forums too.

This link 

http://www.littelfuse.com/~/media/electronics/datasheets/tvs_diodes/littelfuse_tvs_diode_smbj_datasheet.pdf.pdf

 

explains better the characteristics of SMBJ12A, that clearly shows that it is exactly 12v tvs that aslo assures tvs marking.

If I correctly understood Reverse Standoff Volatge is normal voltage for the tvs citcuit, when the Breakdown voltage (13.3 v-14.7 v) is the voltage that should lead to fusing of tvs? Or Clamping voltage is voltage that lead to brokening tvs and shortening its circuit as 19.9 v is far big limit that probably can lead to damage of HD if so?

Anyway it would be fine to know what model is under bux tvs, as there is no bue tvs. Meanwhile this SMBJ12A chaharacteristics should be better compared to concrete samsung hd model limits.

[Andriy M]

Posted on January 06, 2017 at 14:51

Here is P80 samsung HD volatge requirements: 

http://www.samsung.com/us/business/storage/hdd/downloads/2007SSHDDPGB_1st_version.pdf

  Should 12 v 10% means that these hd can withstand just with 10% overvoltage (about 13.2 v) without damage? Or what this upper limit coulld mean?

[Jean-Michel SIMONNET_O]

Posted on January 09, 2017 at 08:55

All parameters in TVS datasheet are guaranteed without damage TVS (short-circuit or failure). TVS gola is to clamp (voltage limiting) over-votlages. If samsung requires 13.2 V, TVS Vrm has to be higher than 13.2 V ==> SMBJ15A

Here is a link about how works TVS.

http://www.st.com/content/ccc/resource/technical/document/application_note/30/f6/d4/72/7d/74/45/bc/CD00003857.pdf/files/CD00003857.pdf/jcr:content/translations/en.CD00003857.pdf

[Andriy M]

Posted on January 10, 2017 at 14:28

Here is almost official reference:

http://www.1688eric.com/en/product.aspx?id=379812

 , and here semiofficial --

http://www.users.on.net/~fzabkar/HDD/TVS_diodes.txt

. The first link seems to confirm that it is 12 v (13.2 brokage voltage) 600 w tvs. Indeed it is not understood why main parameter is 600 w. Was my bux 600 w, or enough lower. And if 600 w - is clamping it could mean that damage could be bring my lower power?

[Andriy M]

Posted on January 10, 2017 at 14:32

Indeed I also do not understand why marking is just refererred on surface of smd?

How to define compatibility in such cases -- f.e. my tvs could be 400 w or 600 w -- how to now?

The second link tells that marking is BU, what do X means.