M27C256B-80N3TR STMicroelectronics, M27C256B-80N3TR Datasheet - Page 6

• Manufacturer Part Number: M27C256B-80N3TR
• Description: 256 Kbit (32Kb x 8) UV EPROM and OTP EPROM
• Manufacturer: STMicroelectronics

M27C256B
Table 8B. Read Mode AC Characteristics
(T
Notes: 1. V
Figure 5. Read Mode AC Waveforms
Programming
When delivered (and after each erasure for UV
EPROM), all bits of the M27C256B are in the ”1”
state. Data is introduced by selectively program-
ming ”0”s into the desired bit locations. Although
only ”0”s will be programmed, both ”1”s and ”0”s
can be present in the data word. The only way to
6/15
Symbol
t
t
EHQZ
GHQZ
A
t
t
t
t
AVQV
GLQV
AXQX
ELQV
= 0 to 70 C, –40 to 85 C, –40 to 105 C or –40 to 125 C; V
2. Sampled only, not 100% tested.
(2)
(2)
CC
Q0-Q7
A0-A14
E
G
must be applied simultaneously with or before V
t
Alt
t
t
ACC
t
t
t
OE
OH
CE
DF
DF
Address Valid to
Output Valid
Chip Enable Low to
Output Valid
Output Enable Low to
Output Valid
Chip Enable High to
Output Hi-Z
Output Enable High
to Output Hi-Z
Address Transition to
Output Transition
Parameter
tAVQV
tELQV
Test Condition
E = V
E = V
tGLQV
VALID
G = V
G = V
E = V
E = V
IL
IL
, G = V
, G = V
(1)
PP
IL
IL
IL
IL
and removed simultaneously or after V
IL
IL
Min
changea ’0’ to a ’1’ is by die expositionto ultraviolet
light (UV EPROM). The M27C256B is in the pro-
gramming mode when V
at V
programmed is applied to 8 bits in parallel to the
data output pins. The levels required for the ad-
dress and data inputs are TTL. V
be 6.25 V
0
0
0
-90
IH
Max Min Max
90
90
40
30
30
and E is pulsed to V
CC
= 5V
tAXQX
0.25 V.
0
0
0
-10
M27C256B
100
100
50
30
30
5% or 5V
tEHQZ
tGHQZ
VALID
PP
Min Max Min Max
0
0
0
.
PP
-12
input is at 12.75V, G is
120
120
60
40
40
10%; V
IL
. The data to be
CC
-15/-20/-25
AI00758B
0
0
0
is specified to
Hi-Z
PP
150
150
= V
65
50
50
CC
Unit
)
ns
ns
ns
ns
ns
ns