1
Features
• Low-voltage and Standard-voltage Operation
– 5.0 (V
CC
= 4.5V to 5.5V)
– 2.7 (V
CC
= 2.7V to 5.5V)
– 2.5 (V
CC
= 2.5V to 5.5V)
– 1.8 (V
CC
= 1.8V to 3.6V)
• Internally Organized 16,384 x 8 and 32,768 x 8
• 2-wire Serial Interface
• Schmitt Trigger, Filtered Inputs for Noise Suppression
• Bidirectional Data Transfer Protocol
• 1 MHz (5V), 400 kHz (2.7V, 2.5V) and 100 kHz (1.8V) Compatibility
• Write Protect Pin for Hardware and Software Data Protection
• 64-byte Page Write Mode (Partial Page Writes Allowed)
• Self-timed Write Cycle (5 ms Typical)
• High Reliability
– Endurance: 100,000 Write Cycles
– Data Retention: 40 Years
– ESD Protection: >4000V
• Automotive Grade and Extended Temperature Devices Available
• 8-pin JEDEC PDIP, 8-pin JEDEC and EIAJ SOIC, 14-pin TSSOP, 8-pin Leadless Array,
and 8-ball dBGA
TM
Packages
Description
The AT24C128/256 provides 131,072/262,144 bits of serial electrically erasable and
programmable read only memory (EEPROM) organized as 16,384/32,768 words of 8
bits each. The device’s cascadable feature allows up to 4 devices to share a common
2-wire bus. The device is optimized for use in many industrial and commercial applica-
tions where low power and low voltage operation are essential. The devices are
available in space-saving 8-pin JEDEC PDIP, 8-pin EIAJ, 8-pin JEDEC SOIC, 14-pin
TSSOP, 8-pin LAP, and 8-ball dBGA packages. In addition, the entire family is avail-
able in 5.0V (4.5V to 5.5V), 2.7V (2.7V to 5.5V), 2.5V (2.5V to 5.5V) and 1.8V (1.8V to
3.6V) versions.
2-wire Serial
EEPROMs
128K (16,384 x 8)
256K (32,768 x 8)
AT24C128
AT24C256
Rev. 0670E–07/01
Pin Configurations
Pin Name Function
A0 - A1 Address Inputs
SDA Serial Data
SCL Serial Clock Input
WP Write Protect
NC No Connect
8-pin PDIP
1
2
3
4
8
7
6
5
A0
A1
NC
GND
VCC
WP
SCL
SDA
8-pin SOIC
1
2
3
4
8
7
6
5
A0
A1
NC
GND
VCC
WP
SCL
SDA
8-pin Leadless Array
Bottom View
1
2
3
4
8
7
6
5
VCC
WP
SCL
SDA
A0
A1
NC
GND
14-pin TSSOP
1
2
3
4
5
6
7
14
13
12
11
10
9
8
A0
A1
NC
NC
NC
NC
GND
VCC
WP
NC
NC
NC
SCL
SDA
8-ball dBGA
Bottom View
VCC
WP
SCL
SDA
A0
A1
NC
GND
1
2
3
4
8
7
6
5
