
1
Features
Low-voltage and Standard-voltage Operation
– 2.7 (V
CC
= 2.7V to 5.5V)
– 1.8 (V
CC
= 1.8V to 3.6V)
Internally Organized 16,384 x 8 and 32,768 x 8
Two-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 Max)
High Reliability
– Endurance: One Million Write Cycles
– Data Retention: 40 Years
Extended Temperature and Lead-free/Halogen-free
Devices Available
8-lead JEDEC PDIP, 8-lead JEDEC and EIAJ SOIC, 8-lead MAP, 8-lead TSSOP, 8-lead
SAP and 8-ball dBGA2
Packages
Die Sales: Wafer Form, Waffle Pack, and Bumped Wafers
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
Two-wire bus. The device is optimized for use in many industrial and commercial appli-
cations 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 EIAJ
SOIC, 8-lead MAP (24C128), 8-lead TSSOP, 8-lead SOIC Array Package and 8-ball
dBGA2 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.
8-lead PDIP
Table 1.
Pin Configuration
Pin Name
Function
A0 - A1
Address Inputs
SDA
Serial Data
SCL
Serial Clock Input
WP
Write Protect
NC
No Connect
GND
Ground
8-lead SAP
Bottom View
1
2
3
4
8
7
6
5
VCC
WP
SCL
SDA
A0
A1
NC
GND
Two-wire Serial
EEPROMs
128K (16,384 x 8)
256K (32,768 x 8)
AT24C128
AT24C256
(1)
Note:
1. Not recommended for
new
design;
refer
to
datasheet.
please
AT24C256B
0670S–SEEPR–5/06
1
2
3
4
8
7
6
5
A0
A1
NC
GND
VCC
WP
SCL
SDA
8-lead SOIC
1
2
3
4
8
7
6
5
A0
A1
NC
GND
VCC
WP
SCL
SDA
8-ball dBGA2
Bottom View
VCC
WP
SCL
SDA
A0
A1
NC
GND
1
2
3
4
8
7
6
5
8-lead TSSOP
1
2
3
4
8
7
6
5
A0
A1
NC
GND
VCC
WP
SCL
SDA
8-lead MAP
Bottom View
1
2
3
4
8
7
6
5
VCC
WP
SCL
SDA
A0
A1
NC
GND