Features

– Endurance: One Million Write Cycles

– Data Retention: 40 Years

Package (SAP), 8-lead TSSOP, and 8-ball dBGA2 Packages

Description

The AT24C256B provides 262,144 bits of serial electrically erasable and programma-

ble read-only memory (EEPROM) organized as 32,768 words of 8 bits each. The

device’s cascadable feature allows up to eight devices to share a common two-wire

bus. The device is optimized for use in many industrial and commercial applications

where low-power and low-voltage operation are essential. The devices are available

in space-saving 8-lead JEDEC PDIP, 8-lead JEDEC SOIC, 8-lead Ultra Thin SAP, 8-

lead TSSOP, and 8-ball dBGA2 packages. In addition, the entire family is available in

a 1.8V (1.8V to 5.5V) version.

Two-wire Serial

EEPROM

256K (32,768 x 8)

AT24C256B

Rev. 5279B–SEEPR–3/08

Pin Configurations

Pin Name

Function

A0–A2

Address Inputs

SDA

Serial Data

SCL

Serial Clock Input

WP

Write Protect

GND

Ground

A0

A1

A2

GND

VCC

WP

SCL

SDA

1

2

3

4

8

7

6

5

VCC

WP

SCL

SDA

8

7

6

5

1

2

3

4

A0

A1

A2

GND

8

7

6

5

1

2

3

4

VCC

WP

SCL

SDA

A0

A1

A2

GND

8-lead PDIP

8-lead SOIC

8-lead dBGA2

Bottom View

8

7

6

5

1

2

3

4

VCC

WP

SCL

SDA

A0

A1

A2

GND

8-lead Ultra Thin SAP

Bottom View

A0

A1

A2

GND

VCC

WP

SCL

SDA

1

2

3

4

8

7

6

5

8-lead TSSOP