Hi Everyone,
Sometimes inductance in the connection to the capacitor can resultant
in a resonant L-C induced overvoltage on powerup. I have seen >50%
overvoltage this way.
Doug
Douglas C. Smith
--------------------------------------------
University of Oxford Course Tutor
Department for Continuing Education
Oxford, Oxfordshire, United Kingdom
--------------------------------------------
PO Box 60941, Boulder City, NV 89006
Email: doug@xxxxxxxxxx
Web: http://www.dsmith.org
Web: http://emcesd.com
Tel: +1-702-570-6108
Mobile: +1-408-858-4528
On Fri, 5 Feb 2016 04:31:01 +0000, "Duraiswamy, Vasudevan"
<vasudevan.duraiswamy@xxxxxxxxxxx> wrote:
Hi
------------------------------------------------------------------
Try to measure the voltage surge during power ON, this may be more
than 20V with the cold start.
Tantalum capacitors are used together with Electrolytic, or TVS diode
can be used in parallel to take care of voltage spike
Reliability of Tantalum improved a lot with new types of Tantalum,
like Tantalum MnO2 and Tantalum Polymer.
Please go through below and some more google search would help,
failure analysis would help to get correct solution
http://powerelectronics.com/passive-components/tantalum-polymer-capacitors-achieve-higher-voltage-ratings
http://www.kemet.com/Lists/TechnicalArticles/Attachments/199/2014%20EDFA%20Tantalum%20Cap%20Failure%20Analysis%20Review%20by%20Javaid%20Qazi.pdf
Have a Nice Day
Regards
Vasu
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx
[mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Bni I
Sent: Thursday, February 04, 2016 9:20 PM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Tantalum explode
Hi experts
I am having issues with my 100uF 20V 1206 tantalum capacitor for 12V input.
The ripple is lower, but close to the limit (said in the DS) [~150mA]
I am facing 20% failure.Most of the time, it explodes on the first power on.
Sadly I have a lot of PCB without any hope to change the PCB.
I haven't found much on the application of the tantalum.
I found that there is some condensation/crystallization time on the
first power up.
The article suggest to use 3xVin [Ohm] serial resistor.
I am not satisfied with this solution. I think it does not help on
the problem.
It only mitigates the problem and it will blow up in my customer hands.
Any experience or artical/book are welcome.
Thanks
Steve
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at:
//www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
________________________________
The information contained in this message may be confidential and
legally protected under applicable law. The message is intended
solely for the addressee(s). If you are not the intended recipient,
you are hereby notified that any use, forwarding, dissemination, or
reproduction of this message is strictly prohibited and may be
unlawful. If you are not the intended recipient, please contact the
sender by return e-mail and destroy all copies of the original
message.
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List forum is accessible at:
http://tech.groups.yahoo.com/group/si-list
List archives are viewable at: //www.freelists.org/archives/si-list
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
