M27C256B-10B1TR STMicroelectronics, M27C256B-10B1TR Datasheet - Page 2

• Manufacturer Part Number: M27C256B-10B1TR
• Description: 256 Kbit (32Kb x 8) UV EPROM and OTP EPROM
• Manufacturer: STMicroelectronics

M27C256B
Figure 2A. DIP Pin Connections
Figure 2C. TSOP Pin Connections
2/15
V CC
V PP
A11
A13
A14
A12
A9
A8
A7
A6
A5
A4
A3
G
V PP
V SS
A12
Q0
Q1
Q2
A7
A6
A5
A4
A3
A2
A1
A0
22
28
1
7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
M27C256B
M27C256B
AI00756
AI00614B
28
27
26
25
24
23
22
21
20
19
18
17
16
15
21
15
14
8
V CC
A14
A13
A8
A9
A11
G
A10
E
Q7
Q6
Q5
Q4
Q3
A10
E
Q7
Q6
Q5
Q4
Q3
V SS
Q2
Q1
Q0
A0
A1
A2
Warning: NC = Not Connected, DU = Dont’t Use.
Figure 2B. LCC Pin Connections
DEVICE OPERATION
The operating modes of the M27C256B are listed
in the Operating Modes. A single power supply is
requiredin the read mode. All inputs are TTL levels
except for V
ture.
Read Mode
The M27C256B has two control functions, both of
which must be logically active in order to obtain
data at the outputs. Chip Enable (E) is the power
control and should be used for device selection.
Output Enable (G) is the output control and should
be used to gate data to the output pins, inde-
pendent of device selection. Assuming that the
addresses are stable, the address access time
(t
Data is available at the output after delay of t
from the falling edge of G, assuming that E has
been low and the addresses have been stable for
at least t
Standby Mode
The M27C256B has a standby mode which re-
duces the supplycurrentfrom 30 mA to 100 A. The
M27C256B is placed in the standby mode by ap-
plying a CMOS high signal to the E input. When in
the standby mode, the outputs are in a high imped-
ance state, independent of the G input.
AVQV
) is equalto the delay from E to output (t
NC
Q0
A6
A5
A4
A3
A2
A1
A0
AVQV
PP
-t
9
GLQV
and 12V on A9 for Electronic Signa-
.
M27C256B
17
1
32
25
AI00757
A8
A9
A11
NC
G
A10
E
Q7
Q6
ELQV
GLQV
).