[SI-LIST] Re: AW: Effect of temperature on at 200C for DDR3/4 boards
- From: Bill Martin <wcmartin1@xxxxxxxxxx>
- To: barthi1@xxxxxxxxx, Hermann Ruckerbauer <hermann.ruckerbauer@xxxxxxxxxxxxx>
- Date: Wed, 16 Dec 2009 07:36:23 -0800 (PST)
Barthi,
A few more items:
For cold temps, you will find the fastest ICs (which might cause timing issues
in your design) and also the highest current consumption.
For cold temps, you will find the slowest ICs (which might cause timing issues).
Make sure you do purchase the right ICs for the environment you need your
product to operate within. Products are only guaranteed for the conditions
that Mfgs warrant. This does not mean Mfgs do full temperature testing;
especially at cold since IC handlers tend to freeze up and get icy). Many Mfgs
will do characterization experiments to determine how to improve test
efficiency (less testing, no burn-in, less test time) while still being able to
screen and ship good devices (100% functionality throughout the operating
voltage, temperature and silicon mfg). Most testing will be performed with
slight temperature guardbands (+2-5 degrees of a spec; 70->74, 85->90, 125->
128) and if Mfgs can avoid (with characterization proof) that cold temp testing
(especially down to -40 or -55) is not required, they will not perform.
regards,
Bill
--- On Wed, 12/16/09, Hermann Ruckerbauer <hermann.ruckerbauer@xxxxxxxxxxxxx>
wrote:
From: Hermann Ruckerbauer <hermann.ruckerbauer@xxxxxxxxxxxxx>
Subject: [SI-LIST] Re: AW: Effect of temperature on at 200C for DDR3/4 boards
To: barthi1@xxxxxxxxx
Cc: si-list@xxxxxxxxxxxxx
Date: Wednesday, December 16, 2009, 3:00 PM
Hi,
I would agree with the previous answers ... don't worry on the PCB
performance to much, the degradation of the silicon is what you need to
take care.
On DRAM side it is not only the change in the OCD (output drivers), but
also the refresh timings are getting quite short for 100°C.
So you really need to do worst case corner simulations over the whole
temperature range.
I guess reliability is something you anyhow take a closer look for your
temperature range ..
regards
Hermann
EKH - EyeKnowHow
Hermann Ruckerbauer
www.EyeKnowHow.de
Hermann.Ruckerbauer@xxxxxxxxxxxxx
Veilchenstrasse 1
94554 Moos
Tel.: +49 (0)9938 / 902 083
Mobile: +49 (0)176 / 787 787 77
Fax: +49 (0)3212 / 121 9008
Havermann, Gert schrieb:
> Hi Barthi,
>
> Your question is how the characteristic impedance of the PCB is affected by
> high temperatures (100°C)?
>
> The Temperature shouldn't have a big influence on impedance. The series
> resistance will increase, but the result will just be higher losses. The
> board sice will increase with temperature, but each differential pair will
> just see fractions of this extra size, in my eyes not enough to worry about
> impedance changes.
>
> I don't think you have to worry about temperature related impedance changes
> on regular PCB at all, but I can't proof that with simulations or
> measurements.
>
> BR
> Gert
>
>
>
> --------------------------------------------------------------------------
> Absender ist HARTING Electronics GmbH & Co. KG; Sitz der Gesellschaft:
> Espelkamp; Registergericht: Bad Oeynhausen; Register-Nr.: HRA 5596;
> persönlich haftende Gesellschafterin: HARTING Electronics Management GmbH;
> Sitz der Komplementär-GmbH: Espelkamp; Registergericht der Komplementär-GmbH:
> Bad Oeynhausen; Register-Nr. der Komplementär-GmbH: HRB 8808;
> Geschäftsführer: Torsten Ratzmann
> -----Ursprüngliche Nachricht-----
>
> Von: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] Im
> Auftrag von Barthi das
> Gesendet: Mittwoch, 16. Dezember 2009 12:57
> An: si-list@xxxxxxxxxxxxx
> Betreff: [SI-LIST] Effect of temperature on at 200C for DDR3/4 boards
>
> Hi,
>
> What is the effect of temperature (200C) on characteristic impedance at
> DDR3/4 speeds and what the best way to control the impedance because of the
> temp effect? Appreciate if anyone sends the literature related to the topic
>
> Thanks
> Barthi
>
>
>
>
>
> ------------------------------------------------------------------
> 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 technical documents are available at:
> http://www.si-list.net
>
> 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
>
>
>
> ------------------------------------------------------------------
> 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 technical documents are available at:
> http://www.si-list.net
>
> 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
>
>
>
>
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
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
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
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
Other related posts:
