M27W801-100B6TR STMICROELECTRONICS [STMicroelectronics], M27W801-100B6TR Datasheet - Page 10

• Manufacturer Part Number: M27W801-100B6TR
• Description: 8 Mbit 1Mb x8 Low Voltage UV EPROM and OTP EPROM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

M27W801
On-Board Programming
The M27W801 can be directly programmed in the
application circuit. See the relevant Application
Note AN620.
Electronic Signature
The Electronic Signature (ES) 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.
The ES mode is functional in the 25 C
bient temperature range that is required when pro-
gramming the M27W801. To activate the ES
mode, the programming equipment must force
11.5V to 12.5V on address line A9 of the
M27W801. Two identifier bytes may then be se-
quenced from the device outputs by toggling ad-
dress line A0 from V
lines must be held at V
ture mode.
Byte 0 (A0 = V
code and byte 1 (A0 = V
code. For the STMicroelectronics M27W801,
these two identifier bytes are given in Table 4 and
can be read-out on outputs Q7 to Q0.
Note that the M27W801 and M27C801 have the
same identifier byte.
10/16
IL
) represents the manufacturer
IL
IL
to V
during Electronic Signa-
IH
) the device identifier
IH
. All other address
5 C am-
ERASURE OPERATION (applies to UV EPROM)
The erasure characteristics of the M27W801 is
such that erasure begins when the cells are ex-
posed to light with wavelengths shorter than ap-
proximately 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
M27W801 in about 3 years, while it would take ap-
proximately 1 week to cause erasure when ex-
posed to direct sunlight. If the M27W801 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 M27W801 window
to prevent unintentional erasure. The recommend-
ed erasure procedure for the M27W801 is expo-
sure 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 30 W-sec/cm
this dosage is approximately 30 to 40 minutes us-
ing an ultraviolet lamp with 12000 W/cm
rating. The M27W801 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 removed before erasure.
2
. The erasure time with
2
power