1

ADVANCEDINFORMATION

Rev. 00B

06/27/06

Copyright © 2006 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability

arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any

published information and before placing orders for products.

IS24C128A

IS24C256A

128K-bit/ 256K-bit

2-WIRE SERIAL CMOS EEPROM

ADVANCED INFORMATION

JULY 2006

DESCRIPTION

The IS24C128A/256A is an electrically erasable PROM

device that uses the standard 2-wire interface for

communications. The IS24C128A is 128K-bit (16Kx8)

and the IS24C256A is 256K-bit (32Kx8). These

EEPROM are offered in a wide operating voltage range

of 1.8V to 5.5V to be compatible with most application

voltages. ISSI designed the IS24C128A/256A to be an

efficient 2-wire EEPROM solution. The devices are

packaged in 8-pin PDIP, 8-pin (JEDEC) SOIC, and 8-

pin (EIAJ) SOIC.

The IS24C128A/256A maintains compatibility with the

popular 2-wire bus protocol, so it is easy to design into

applications implementing this bus type. The simple

bus consists of the Serial Clock wire (SCL) and the

Serial Data wire (SDA). Using the bus, a Master device

such as a microcontroller is usually connected to one

or more Slave devices such as the IS24C128A/256A.

The bit stream over the SDA line includes a series of

bytes, which identifies a particular Slave device, an

instruction, an address within that Slave device, and a

series of data, if appropriate. The IS24C128A/256A has

a Write Protect pin (WP) to allow blocking of any write

instruction transmitted over the bus.

FEATURES

–Bi-directional data transfer protocol

• Wide Voltage Operation

–Vcc = 1.8V to 5.5V

• 400 KHz (2.5V) and 1 MHz (5.0V) compatibility

• Low Power CMOS Technology

–Active Current less than 3 mA (2.5V)

–Standby Current less than 20 µA (2.5V)

• Hardware Data Protection

–Write Protect Pin

• Sequential Read Feature

• Filtered Inputs for Noise Suppression

• Self time write cycle with auto clear

–5 ms @ 2.5V

• Organization:

–16Kx8 (256 pages of 64 bytes)

–32Kx8 (512 pages of 64 bytes)

• 64 Byte Page Write Buffer

• High Reliability

–Endurance: 1,000,000 Cycles

–Data Retention: 40 Years

• Industrial and Automotive temperature ranges

• 8-pin PDIP, 8-pin (JEDEC) SOIC, and 8-pin

(EIAJ) SOIC packages

• Lead-free available