AT25256A Datasheet, PDF (1/18 Pages) ATMEL Corporation – SPI Serial Extended Temperature EEPROMs

Features
• Serial Peripheral Interface (SPI) Compatible
• Supports SPI Modes 0 (0,0) and 3 (1,1)
– Data Sheet Describes Mode 0 Operation
• Medium-voltage and Standard-voltage Operation
– 5.0 (V_CC = 4.5V to 5.5V)
– 2.7 (V_CC = 2.7V to 5.5V)
• Extended Temperature Range −40°C to +125°C
• 5 MHz Clock Rate
• 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: 100,000 Write Cycles
– Data Retention: >100 Years
• 8-lead PDIP, 8-lead JEDEC SOIC, and 8-lead TSSOP Packages
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 automotive applications
where low-power and low-voltage operation are essential. The devices are available in
space-saving 8-lead PDIP, 8-lead JEDEC SOIC, and 8-lead TSSOP packages.
The AT25128A/256A is enabled through the Chip Select pin (CS) and accessed via a
three-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.
Table 1. Pin Configurations
Pin Name
Function
CS
Chip Select
SCK
Serial Data Clock
SI
Serial Data Input
SO
Serial Data Output
GND
Ground
VCC
Power Supply
WP
Write Protect
HOLD
Suspends Serial Input
NC
No Connect
DC
Don't Connect
8-Lead PDIP
CS 1
SO 2
WP 3
GND 4
8 VCC
7 HOLD
6 SCK
5 SI
8-lead SOIC
CS 1
SO 2
WP ₃
GND ₄
8 VCC
7 HOLD
6 SCK
5 ^SI
8-lead TSSOP
CS 1
SO 2
WP 3
GND 4
8 VCC
7 HOLD
6 SCK
5 SI
SPI Serial
Extended
Temperature
EEPROMs
128K (16,384 x 8)
256K (32,768 x 8)
AT25128A
AT25256A
5088C–SEEPR–11/04
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