W27E257

32K

× 8 ELECTRICALLY ERASABLE EPROM

Publication Release Date: January 1997

- 1 -

Revision A3

GENERAL DESCRIPTION

The W27E257 is a high-speed, low-power Electrically Erasable and Programmable Read Only

Memory organized as 32768

× 8 bits that operates on a single 5 volt power supply. The W27E257

provides an electrical chip erase function. This part was the same EPROM Writer's utilities as the

W27E256.

FEATURES

100/120/150 nS (max.)

1 mA (typ.)

µA (typ.)

compatible

32-pin PLCC

PIN CONFIGURATIONS

A6

A5

A4

A3

A2

A1

A0

NC

Q0

5

6

7

8

9

10

11

12

13

1

4

4

3

2

1

3

2

3

1

3

0 29

28

27

26

25

24

23

22

21

32-pin

PLCC

Q

1

Q

2

N

C

Q

3

Q

4

Q

5

G

N

D

26

27

28

1

2

3

4

5

6

7

8

21

22

23

24

25

16

17

18

19

20

9

10

11

12

13

14

15

Q3

CE

Q7

Q6

Q5

Q4

A9

A11

OE

A10

A14

A13

A8

1

5

1

6

1

7

1

8

1

9

2

0

GND

Q2

Q1

A0

A1

A2

A3

A4

A5

A6

A7

A12

V

Q0

PP

V

CC

A

7

N

C

A

1

2

V

P

P

A

1

4

A

1

3

V

C

C

A8

A9

A11

NC

OE

A10

Q7

CE

Q6

28-pin

DIP

BLOCK DIAGRAM

CE

OE

CONTROL

OUTPUT

BUFFER

DECODER

CORE

ARRAY

Q0

Q7

.

.

A0

.

.

A14

V

GND

CC

VPP

PIN DESCRIPTION

SYMBOL

DESCRIPTION

A0

−A14

Address Inputs

Q0

−Q7

Data Inputs/Outputs

CE

Chip Enable

OE

Output Enable

Program/Erase Supply Voltage

Power Supply

GND

Ground

NC

No Connection