M27512-20F1 STMicroelectronics, M27512-20F1 Datasheet - Page 9

• Manufacturer Part Number: M27512-20F1
• Description: NMOS 512K 64K x 8 UV EPROM
• Manufacturer: STMicroelectronics

Electronic Signature
The Electronic Signature mode allows the reading
out of a binary code from an EPROM that will
identify its manufacturer and type. This mode is
intended for use by programming equipment to
automatically match the device to be programmed
with its corresponding programming algorithm.
This mode is functional in the 25 C 5 C ambient
temperature range that is required when program-
ming the M27512. To activate this mode, the pro-
gramming equipment must force 11.5V to 12.5V on
address line A9 of the M27512. Two identifier bytes
may then be sequenced from the device outputs by
toggling address line A0 from V
address lines must be held at V
Signature mode, except for A14 and A15 which
should be high. Byte 0 (A0 = V
manufacturer code and byte 1 (A0 = V
identifier code.
ERASURE OPERATION (applies to UV EPROM)
The erasure characteristic of the M27512 is such
that erasure begins when the cells are exposed to
ORDERING INFORMATION SCHEME
For a list of available options (Speed, V
catalogue.
For further information on any aspect of this device, please contact SGS-THOMSON Sales Office nearest
to you.
blank
-20
-25
Example:
-2
-3
Speed and V
200 ns, 5V 5%
250 ns, 5V 5%
300 ns, 5V 5%
200 ns, 5V 10%
250 ns, 5V 10%
CC
IL
Tolerance
IL
IL
during Electronic
) represents the
to V
IH
IH
) the device
CC
M27512
. All other
Tolerance, Package, etc) refer to the current Memory Shortform
F
-2
light with wavelengths shorter than approximately
4000 Å. It should be noted that sunlight and some
type of fluorescent lamps have wavelengths in the
3000-4000 Å range. Research shows that constant
exposure to room level fluorescent lighting could
erase a typical M27512 in about 3 years, while it
would take approximately 1 week to cause erasure
when expose to direct sunlight. If the M27512 is to
be exposed to these types of lighting conditions for
extended periods of time, it is suggested that
opaque labels be put over the M27512 window to
prevent unintentional erasure. The recommended
erasure procedure for the M27512 is exposure to
short wave ultraviolet light which has wavelength
2537 Å.
The integrated dose (i.e. UV intensity x exposure
time) for erasure should be a minimum of 15
W-sec/cm
approximately 15 to 20 minutes using an ultraviolet
lamp with 12000
M27512 should be placed within 2.5 cm (1 inch) of
the lamp tubes during the erasure. Some lamps
have a filter on their tubes which should be re-
moved before erasure.
Package
FDIP28W
F
1
2
. The erasure time with this dosage is
W/cm
Temperature Range
1
6
2
–40 to 85 C
0 to 70 C
power rating. The
M27512
9/11