2

Integrated Silicon Solution, Inc. — 1-800-379-4774

SR020-1O

05/24/99

IS61C256AH

1

2

3

4

5

6

7

8

9

10

11

12

13

14

28

27

26

25

24

23

22

21

20

19

18

17

16

15

A14

A12

A7

A6

A5

A4

A3

A2

A1

A0

I/O0

I/O1

I/O2

GND

VCC

WE

A13

A8

A9

A11

OE

A10

CE

I/O7

I/O6

I/O5

I/O4

I/O3

PIN CONFIGURATION

28-Pin DIP and SOJ

PIN CONFIGURATION

28-Pin TSOP

PIN DESCRIPTIONS

A0-A14

Address Inputs

CE

Chip Enable Input

OE

Output Enable Input

WE

Write Enable Input

I/O0-I/O7

Bidirectional Ports

Vcc

Power

GND

Ground

Symbol

Parameter

Value

Unit

Terminal Voltage with Respect to GND

–0.5 to +7.0

V

Temperature Under Bias

–55 to +125

°C

Storage Temperature

–65 to +150

°C

Power Dissipation

1.5

W

DC Output Current (LOW)

20

mA

Note:

1. Stress greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause

permanent damage to the device. This is a stress rating only and functional operation of the

device at these or any other conditions above those indicated in the operational sections of

this specification is not implied. Exposure to absolute maximum rating conditions for extended

periods may affect reliability.

22

23

24

25

26

27

28

1

2

3

4

5

6

7

21

20

19

18

17

16

15

14

13

12

11

10

9

8

OE

A11

A9

A8

A13

WE

VCC

A14

A12

A7

A6

A5

A4

A3

A10

CE

I/O7

I/O6

I/O5

I/O4

I/O3

GND

I/O2

I/O1

I/O0

A0

A1

A2

TRUTH TABLE

Mode

WE

WE

WE

WE

WE

CE

CE

CE

CE

CE

OE

OE

OE

OE

OE I/O Operation Vcc Current

Not Selected

X

H

X

High-Z

(Power-down)

Output Disabled H

L

H

High-Z

Read

H

L

L

Write

L

L

X