Features
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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
Automotive Grade, Extended Temperature and Lead-free/Halogen-free
Devices Available
8-lead PDIP, 8-lead EIAJ SOIC, 8-lead JEDEC SOIC, 8-lead TSSOP, 8-ball dBGA2 and
8-lead SAP Packages
Die Sales: Wafer Form, Waffle Pack, and Bumped Die
SPI Serial
EEPROMs
128K (16,384 x 8)
256K (32,768 x 8)
Description
The AT25128A/256A provides 131,072/262,144 bits of serial electrically-erasable
programmable 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
appli-
cations 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.
8-lead PDIP
8-lead SOIC
VCC
HOLD
SCK
SI
CS
SO
WP
GND
1
2
3
4
8
7
6
5
VCC
HOLD
SCK
SI
AT25128A
AT25256A
Table 1.
Pin Configurations
Pin Name
CS
SCK
SI
SO
GND
VCC
WP
HOLD
NC
Function
Chip
Select
Serial
Data Clock
Serial
Data Input
Serial
Data Output
Ground
Power
Supply
Write Protect
Suspends Serial
Input
No Connect
CS
SO
WP
GND
1
2
3
4
8
7
6
5
8-lead TSSOP
CS
SO
WP
GND
1
2
3
4
8
7
6
5
VCC
HOLD
SCK
SI
VCC
HOLD
SCK
SI
8-lead SAP
8
7
6
5
1
2
3
4
CS
SO
WP
GND
8-ball dBGA2
VCC
HOLD
SCK
SI
8
7
6
5
1
2
3
4
Bottom View
CS
SO
WP
GND
Bottom View
3368H–SEEPR–8/05
1
ATMEL [ ATMEL CORPORATION ]
