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Preparation for Use
EPROM Erasure
You can erase EPROMs by exposing the integrated circuit to ultraviolet light
through a window on the chip package. Erasure occurs when the exposure light
has a wavelength shorter than approximately 4000 Angstroms.
Sunlight and some florescent lamps have wavelengths in the 3000-4000 Angstrom
range. Constant exposure to room-level florescent light erases the typical EPROM
in approximately three years, while exposing the EPROM to direct sunlight erases
it in about one week.
If the EPROM device is exposed to these lighting conditions for extended periods
of time, you should cover the device window with opaque labels (available from
Intel) to prevent unintentional erasure.
The optimum light for erasing EPROMs has a wavelength of 2537 Angstroms.
The integrated dose (UV intensity X exposure time) for erasure should be a mini
mum of 15 W-sec/cm2. The erasure time is approximately 15 to 20 minutes using
an ultraviolet lamp with 12,000 uW/cm2 power rating. The EPROM should be
within one inch of the lamp tubes during erasure.
Do not power up the EPROM during erasure. If you power up the EPROM device
during erasure, the internal current paths will cancel the energy that the ultraviolet
light provides, and the device will not be erased.
C onsult the Microcontroller Handbook, the Microprocessor and Peripheral
Handbook, and the Memory Components Handbook fox further information on eras
ing EPROM components. Individual device specifications also contain erasure
information.
Installation Procedures
This section describes installation procedures for the universal programmer.
To prevent possible damage to the universal programmer, verify
that the line voltage select switches are set properly and the power
fuse is the right value for the line voltage that is to be used before
plugging in the unit and turning it on. Refer to the Setting Line
Voltage and Checking and Replacing Power Fuse sections in this
chapter.
Setting Line Voltage
Only a qualified technical person should change the line voltage
setting.
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I C A U TIO N 1
W A R N IN G I
iUP-200A/201A
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