1
2
3
4
8
7
6
5
CS
SO
WP
GND
VCC
HOLD
SCK
SI
8-lead PDIP
1
2
3
4
8
7
6
5
CS
SO
WP
GND
VCC
HOLD
SCK
SI
8-lead SOIC
1
2
3
4
8
7
6
5
CS
SO
WP
GND
VCC
HOL
SCK
SI
8-lead TSSOP
1
2
3
4
8
7
6
5
VCC
HOLD
SCK
SI
CS
SO
WP
GND
8-lead Ultra Thin SAP
VCC
HOLD
SCK
S
I
CS
SO
WP
GND
1
2
3
4
8
7
6
5
8-ball dBGA2
Bottom View
Bottom View
Features
• Serial Peripheral Interface (SPI) Compatible
• Supports SPI Modes 0 (0,0) and 3 (1,1)
• Data Sheet Describes Mode 0 Operation
• Low-voltage and Standard-voltage Operation
– 2.7 (V
CC
= 2.7V to 5.5V)
– 1.8 (V
CC
= 1.8V to 5.5V)
• 20 MHz Clock Rate (5V)
• 64-byte Page Mode and Byte Write Operation
• Block Write Protection
– Protect 1/4, 1/2, or Entire Array
• Write Protect (WP) Pin and Write Disable Instructions for
Both Hardware and Software Data Protection
• Self-timed Write Cycle (5 ms Max)
• High-reliability
– Endurance: 1 Million Write Cycles
– Data Retention: >100 Years
• 8-lead PDIP, 8-lead EIAJ SOIC, 8-lead JEDEC SOIC, 8-lead TSSOP, 8-ball dBGA2 and 8-
lead Ultra Thin SAP Packages
• Lead-free/Halogen-free
• Available in Automotive
• Die Sales: Wafer Form, Waffle Pack, and Bumped Die
Description
The AT25128A/256A provides 131,072/262,144 bits of serial electrically-erasable pro-
grammable read only memory (EEPROM) organized as 16,384/32,768 words of 8 bits
each. The device is optimized for use in many industrial and commercial applications
where low-power and low-voltage operation are essential. The devices are available
in space saving 8-lead PDIP, 8-lead EIAJ SOIC, 8-lead JEDEC SOIC, 8-lead TSSOP,
8-ball dBGA2 and 8-lead SAP packages. In addition, the entire family is available in
2.7V (2.7V to 5.5V) and 1.8V (1.8V to 5.5V) versions.
The AT25128A/256A is enabled through the Chip Select pin (CS) and accessed via a
3-wire interface consisting of Serial Data Input (SI), Serial Data Output (SO), and
Serial Clock (SCK). All programming cycles are completely self-timed, and no sepa-
rate Erase cycle is required before Write.
3368J–SEEPR–06/07
SPI Serial
EEPROMs
128K (16,384 x 8)
256K (32,768 x 8)
AT25128A
AT25256A
Not
Recommended
for New Design
