Old EPROM questions again, EPROM Programmer

From: Joe R. <rigdonj_at_cfl.rr.com>
Date: Fri Jul 30 10:01:59 2004

At 01:51 AM 7/30/04 +0000, Ethan wrote:
>On Fri, Jul 30, 2004 at 02:13:47AM +0100, Davison, Lee wrote:
>>
>> >>I have a couple of "ultraviolet" LEDs with me, but I doubt they are the
>> >>right frequency to erase EPROMs.
>>
>> > If they're the high power UV LEDs then they should work. A friend of
>> > mine uses those to erase his EPROMs and the erase time is about the same
>> > as for a UV light.
>>
>> There are not yet available UV LEDs that radiate at short enough wavelength
>> to erase EPROMs in a reasonable time. Most EPROMs will start to erase at
>> <400nm but take hours of exposure, to erase an EPROM in 20 mins or so needs
>> 12mW/cm^2 of 257nm light on the die face. The longer wavelengths just warm
>> the chip up a bit.
>
>I will have to check, but IIRC, my LEDs are 450nm.

   I just called and talked to my friend about this. He has some >>
prototype << high power UV LEDs that are about 375nm. He also some that are
deeper UV but the phone connection was lousy and I couldn't get any more
details. I'm not even sure which ones he used to erase the EPROMs with or
how long it took. Your 450nm LEDs probably won't work.

   Joe
Received on Fri Jul 30 2004 - 10:01:59 BST