M27C4002-70F1 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
Manufacturer
M27C4002-70F1 Datasheet PDF : 24 Pages
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M27C4002
Device operation
M27C4002, these two identifier bytes are given in Table 3: Electronic Signature and can be
read-out on outputs Q7 to Q0.
2.10 Erasure operation (applies to UV EPROM)
The erasure characteristics of the M27C4002 are such that erasure begins when the cells
are exposed to 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 M27C4002 in about 3 years, while it would take approximately 1 week to
cause erasure when exposed to direct sunlight. If the M27C4002 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 M27C4002 window to prevent unintentional erasure. The recommended
) erasure procedure for the M27C4002 is exposure to short wave ultraviolet light which has
t(s wavelength 2537 Å. The integrated dose (i.e. UV intensity x exposure time) for erasure
c should be a minimum of 15 W-sec/cm2. The erasure time with this dosage is approximately
u 15 to 20 minutes using an ultraviolet lamp with 12000 µW/cm2 power rating. The M27C4002
d should be placed within 2.5cm (1 inch) of the lamp tubes during the erasure. Some lamps
ro have a filter on their tubes which should be removed before erasure.
te P Table 2. Operating modes(1)
le Mode
E
G
so Read
VIL
VIL
b Output Disable
VIL
VIH
- O Program
VIL Pulse
VIH
t(s) Verify
VIH
VIL
c Program Inhibit
VIH
VIH
du Standby
VIH
X
ro Electronic Signature
VIL
VIL
P 1. X = VIH or VIL, VID = 12V ± 0.5V.
teTable 3. Electronic Signature(1)
le Identifier
A0 Q7 Q6 Q5 Q4
A9
VPP
Q15-Q0
X
VCC or VSS Data Out
X
VCC or VSS
Hi-Z
X
VPP
Data In
X
VPP
Data Out
X
VPP
Hi-Z
X
VCC or VSS
Hi-Z
VID
VCC
Codes
Q3 Q2 Q1 Q0 Hex Data
bso Manufacturer’s
O Code
VIL
0
0
1
0
0
0
0
0
20h
Device Code
VIH
0
1
0
0
0
1
0
0
44h
1. Outputs Q15-Q8 are set to '0'.
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