[SI-LIST] Re: help me
- From: "Mahabala Shetty" <mahabalashetty@xxxxxxxxxxx>
- To: ludwig@xxxxxxxxxxxxxxxxx, zhang_kun@xxxxxxxxxx, jagaveer25@xxxxxxxxxxx
- Date: Fri, 03 Feb 2006 08:51:09 +0000
Jagveer,
Connect a voltage source where u can limit the current and slowly increase
the current.
The board resistance will definitely drop as the devices are in parallel,
3ohms is not a perfect short condition.
Regards,
Mahabala.
----------------------------------------------------------------------------
From: Stefan Ludwig <ludwig@xxxxxxxxxxxxxxxxx>
Reply-To: ludwig@xxxxxxxxxxxxxxxxx
To: zhang_kun@xxxxxxxxxx, jagaveer25@xxxxxxxxxxx
CC: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: help me
Date: Fri, 03 Feb 2006 09:46:52 +0100
>Jagaveer, Zhangkun,
>
>Zhangkun is right, 3 Ohms on a board with mounted chips is not an issue.
>
>The reason is because of leakage current in transistors. As process
>technology progresses (180nm -> 130nm -> 90nm ...), the leakage current
>in a transistor gets bigger. That is, a transistor, even when it is
>"off", will have some current flowing through it. Also, you can pack
>more transistors onto a chip. Therefore, you end up with tens to
>hundreds of millions of leaky transistors, which leads to a low
>resistance when measured with an Ohm-meter.
>
>Cheers,
>
>Stefan Ludwig
>
>zhangkun 29902 wrote:
>
>>Dear jagaveer
>>
>>Do not worry about the problem. I have met this kind of problem for
severaltimes. When the IC is soldered on the PCB, the dc resistance between
power and ground is very small.
>>
>>However, I am not sure the reason. The IC vendor did not explain it:(
>>
>>Best Regards
>>
>>Zhangkun
>>2006.2.3
>>
>>
>>***************************************************************************
***************
>>This email and its attachments contain confidential information from
HUAWEI, which is intended only for the person or entity whose address is
listed above. Any use of the information contained herein in any way
(including, but not limited to, total or partial disclosure, reproduction,
ordissemination) by persons other than the intended recipient(s) is
prohibited. If you receive this e-mail in error, please notify the sender by
phone or email immediately and delete it!
>>***************************************************************************
**************
>>
>>----- Original Message -----
>>From: jagaveer25 <jagaveer25@xxxxxxxxxxx>
>>Date: Friday, February 3, 2006 12:25 pm
>>Subject: [SI-LIST] help me
>>
>>
>>
>>>Hi folks,
>>>
>>>
>>>I have done in one PCB. It is 12 layer board
>>>
>>>I have used 4 digital signal processor and one field programmable
>>>gate array for this pcb .
>>>
>>>Dsp side I have used 3 pwr supplies
>>>
>>>1v
>>>1.5v
>>>2.5v
>>>before I have populated that dsp I have checked between the all
>>>pwr
>>>supply and gnd resistance is very high resistance but
>>>after I have populated that 3 dsp I have checked between the
>>>1Vpwr
>>>supply and gnd resistance is only 3 ohms
>>>
>>>my 1v pwr section is 20A design
>>>
>>>I can't understand this type of problem
>>>Can u give any solution for this problem I have appreciate it
>>>
>>>Thanks
>>>V.jagaveer
>>>
>>>
>>>
>>
>>
>>
>
>--
>
>Ludwig Systems Engineering Consulting - Design - Implementation
>WWW: www.ludwigsystems.com System Architectures - FPGAs - PCBs
>Ph/Fx: +41-43-355-58-73/74 Hardware - Firmware - Software
>
>------------------------------------------------------------------
>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 FAQ wiki page is located at:
> http://si-list.org/wiki/wiki.pl?Si-List_FAQ
>
>List technical documents are available at:
> http://www.si-list.org
>
>List archives are viewable at:
>//www.freelists.org/archives/si-list
>or at our remote archives:
>http://groups.yahoo.com/group/si-list/messages
>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 FAQ wiki page is located at:
http://si-list.org/wiki/wiki.pl?Si-List_FAQ
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
