TECHNET Archives

June 2004

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
"Dehoyos, Ramon" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Fri, 18 Jun 2004 07:23:35 -0700
Content-Type:
text/plain
Parts/Attachments:
text/plain (47 lines)
        Hi Brian:
                        I did some research on magnetic fields negative effects on EEPROM and did not find anything solid. Called TI and other companies and did not get a good answer or no reply at all. This is what I got from TI

Ramon,

Thank you for contacting the Product Information Center at Texas Instruments. My apologies for the delayed response. In reference to your inquiry, we no longer manufacturer memory devices and there is no one in place to answer this general question on EPROMs. The individuals that once supported our memory devices are no longer available to contact for assistance. We apologize for any inconvenience this may cause and if there is anything else that we can help you with, please let us know.

Regards,

Rodney T. Brown
Texas Instruments

THREAD ID:1-K8MXN][SYS:Done]


        But I did find out that at least some of the EEPROM are built utilizing FETs (field effect transistors). From my EE major and experience in building ICs for many years, reading to refresh on some articles about EEPROMs and talking to some techs that work with EEPROMs all the time, this what I concluded. The gate input in a FET affects the source drain path by just having a potential in proximity to that path between the two, that increases the depletion region to the point of stopping the current or allowing the current to flow. So a magnetic flux in theory can do the same.  It seems that it does not take a large input to erase a cell in an EEPROM but it takes a larger potential to write on it. One of the techs here made a comment to me that a magnetic flux can scramble the program of an EEPROM. This tech has been with the company for a long time and has many years of experience
with direct usage of EEPROMs, so his comment is not taken lightly. I would like to get my hands on some EEPROMs and do some experimentation, but it would be a little difficult. Also the gate length is getting smaller and smaller, 40 nano meters???, about 0.002 mils. This means less potential to turn on and off a transistor. Do you wonder why some many car programs need to be reset by the dealers?  or why so many of the equipment is packaged in metal to avoid interference?  Brian I know it is not much but that is all I was able to find out. First opportunity I have I will find out first hand whether MF does or not affect EEPROMs. In the mean time, I will keep any magnetized tools away from boards.
        Regards,
        Ramon



-----Original Message-----
From: Brian Ellis [mailto:[log in to unmask]]
Sent: Saturday, June 12, 2004 2:15 AM
To: TechNet E-Mail Forum.; Dehoyos, Ramon
Subject: Re: [TN] FW: [TN] Magnetic Screwdrivers


But please tell me what mechanism could cause an EPROM, of any type, to
be affected by a magnetic field. I maintain that it is impossible, but
I'm open to correction if you can show me a logical explanation.

Brian

>

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

ATOM RSS1 RSS2