A1

A0

Q0

A7

A4

A3

A2

A6

A5

A13

A10

A8

A9

Q7

A14

A11

G

E

Q5

Q1

Q2

Q3

VSS

Q4

Q6

A12

VPP

VCC

AI00768

M27256

8

1

2

3

4

5

6

7

9

10

11

12

13

14

16

15

28

27

26

25

24

23

22

21

20

19

18

17

Figure 2. DIP Pin Connections

Symbol

Parameter

Value

Unit

Ambient Operating Temperature

grade 1

grade 6

0 to 70

–40 to 85

°C

Temperature Under Bias

grade 1

grade 6

–10 to 80

–50 to 95

°C

Storage Temperature

–65 to 125

°C

Input or Output Voltages

–0.6 to 6.25

V

Supply Voltage

–0.6 to 6.25

V

VA9 Voltage

–0.6 to 13.5

V

Program Supply

–0.6 to 14

V

Note: Except for the rating "Operating Temperature Range", stresses above those listed in the Table "Absolute Maximum Ratings" may cause

permanent damage to the device. These are stress ratings only and operation of the device at these or any other conditions above those

indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum Rating conditions for ex tended periods

may affect device reliability. Refer also to the STMicroelectronics SURE Program and other relevant quality documents.

Table 2. Absolute Maximum Ratings

DEVICE OPERATION

The eight modes of operations of the M27256 are

listed in the Operating Modes Table. A single 5V

power supply is required in the read mode. All

for Electronic Signature.

Read Mode

The M27256 has two control functions, both of

which must be logically satisfied 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

is available at the outputs after the falling edge of

G, assuming that E has been low and the ad-

Standby Mode

The M27256 has a standby mode which reduces

the maximum active power current from 100mA to

40mA. The M27256 is placed in the standby mode

by applying a TTL high signal to the E input. When

in the standby mode, the outputs are in a high

impedance state, independent of the G input.

Two Line Output Control

Because EPROMs are usually used in larger mem-

ory arrays, this product features a 2 line control

function which accommodates the use of multiple

memory connection. The two line control function

allows:

a. the lowest possible memory power dissipation,

b. complete assurance that output bus contention

will not occur.

M27256

2/10