Features
• Low-voltage and Standard-voltage Operation
– 2.7 (VCC = 2.7V to 5.5V)
– 1.8 (VCC = 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)
2-wire Serial
EEPROMs
• High Reliability
– Endurance: 100,000 Write Cycles
– Data Retention: 40 Years
• Automotive Grade and Extended Temperature Devices Available
• 8-pin JEDEC PDIP, 8-pin JEDEC and EIAJ SOIC, 8-pin TSSOP, 14-pin TSSOP and 8-ball
dBGATM Packages
128K (16,384 x 8)
256K (32,768 x 8)
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 JEDEC SOIC, 8-pin EIAJ SOIC, 8-
pin TSSOP, 14-pin TSSOP and 8-ball dBGA packages. In addition, the entire family is
available in 2.7V (2.7V to 5.5V) and 1.8V (1.8V to 3.6V) versions.
AT24C128
AT24C256
8-pin PDIP
8-pin SOIC
Pin Configurations
A0
A1
1
2
3
4
8
7
6
5
VCC
WP
Pin Name
A0 - A1
SDA
Function
A0
A1
1
2
3
4
8
7
6
5
VCC
WP
Address Inputs
Serial Data
NC
SCL
SDA
NC
SCL
SDA
GND
GND
SCL
Serial Clock Input
Write Protect
No Connect
8-pin TSSOP
8-ball dBGA
WP
8
7
6
5
1
2
3
4
A0
VCC
NC
A0
1
2
3
4
8
7
6
5
VCC
A1
WP
SCL
SDA
A1
NC
WP
NC
SCL
SDA
GND
GND
Bottom View
14-pin TSSOP
A0
A1
1
2
3
4
5
6
7
14
13
12
11
10
9
VCC
WP
NC
NC
NC
NC
NC
NC
NC
SCL
SDA
GND
8
Rev. 0670G–SEEPR–05/02
1