AT24C128/256

2

Absolute Maximum Ratings*

Block Diagram

Pin Description

SERIAL CLOCK (SCL): The SCL input is used to positive

edge clock data into each EEPROM device and negative

edge clock data out of each device.

SERIAL DATA (SDA): The SDA pin is bidirectional for

serial data transfer. This pin is open-drain driven and may

be wire-ORed with any number of other open-drain or open

collector devices.

DEVICE/PAGE ADDRESSES (A1, A0): The A1 and A0

pins are device address inputs that are hardwired or left not

connected for hardware compatibility with AT24C32/64.

When the pins are hardwired, as many as four 128K/256K

devices may be addressed on a single bus system (device

addressing is discussed in detail under the Device

Addressing section). When the pins are not hardwired, the

default A

WRITE PROTECT (WP): The write protect input, when tied

to GND, allows normal write operations. When WP is tied

high to V

ited. If left unconnected, WP is internally pulled down to

GND. Switching WP to V

ates a software write protect function.

Memory Organization

AT24C128/256, 128K/256K SERIAL EEPROM: The

128K/256K is internally organized as 256/512 pages of 64-

bytes each. Random word addressing requires a 14/15-bit

data word address.

Operating Temperature .................................. -55

°C to +125°C

*NOTICE:

Stresses beyond those listed under “Absolute

Maximum Ratings” may cause permanent dam-

age to the device. This is a stress rating only and

functional operation of the device at these or any

other conditions beyond those indicated in the

operational sections of this specification is not

implied. Exposure to absolute maximum rating

conditions for extended periods may affect device

reliability.

Storage Temperature ..................................... -65

°C to +150°C

Voltage on Any Pin

with Respect to Ground .....................................-1.0V to +7.0V

Maximum Operating Voltage........................................... 6.25V

DC Output Current........................................................ 5.0 mA