FM25256B Datasheet, PDF (1/13 Pages) Ramtron International Corporation – 256Kb FRAM Serial 5V Memory

FM25256B
256Kb FRAM Serial 5V Memory
Features
256K bit Ferroelectric Nonvolatile RAM
• Organized as 32,768 x 8 bits
• Virtually Unlimited Endurance (10¹⁴ Cycles)
• 10 Year Data Retention
• NoDelay™ Writes
• Advanced High-Reliability Ferroelectric Process
Very Fast Serial Peripheral Interface - SPI
• Up to 20 MHz Frequency
• Direct Hardware Replacement for EEPROM
• SPI Mode 0 & 3 (CPOL, CPHA=0,0 & 1,1)
Description
The FM25256B is a 256-kilobit nonvolatile memory
employing an advanced ferroelectric process. A
ferroelectric random access memory or FRAM is
nonvolatile and performs reads and writes like a
RAM. It provides reliable data retention for 10 years
while eliminating the complexities, overhead, and
system level reliability problems caused by
EEPROM and other nonvolatile memories.
Unlike serial EEPROMs, the FM25256B performs
write operations at bus speed. No write delays are
incurred. The next bus cycle may commence
immediately without the need for data polling. The
next bus cycle may start immediately. In addition, the
product offers virtually unlimited write endurance.
Also, FRAM exhibits much lower power
consumption than EEPROM.
These capabilities make the FM25256B ideal for
nonvolatile memory applications requiring frequent
or rapid writes or low power operation. Examples
range from data collection, where the number of
write cycles may be critical, to demanding industrial
controls where the long write time of EEPROM can
cause data loss.
The FM25256B provides substantial benefits to users
of serial EEPROM as a hardware drop-in
replacement. The FM25256B uses the high-speed SPI
bus, which enhances the high-speed write capability
of FRAM technology. Device specifications are
guaranteed over an industrial temperature range of
-40°C to +85°C.
Write Protection Scheme
• Hardware Protection
• Software Protection
Wide Operating Range
• Wide Voltage Operation 4.0V – 5.5V
Industry Standard Configurations
• Industrial Temperature -40°C to +85°C
• 8-pin “Green”/RoHS SOIC (-G)
Pin Configuration
CS
1
SO
2
WP
3
VSS
4
8
VDD
7
HOLD
6
SCK
5
SI
Pin Name
/CS
/WP
/HOLD
SCK
SI
SO
VDD
VSS
Function
Chip Select
Write Protect
Hold
Serial Clock
Serial Data Input
Serial Data Output
Supply Voltage (4.0 to 5.5V)
Ground
Ordering Information
FM25256B-G “Green”/RoHS 8-pin SOIC
This product conforms to specifications per the terms of the Ramtron
standard warranty. The product has completed Ramtron’s internal
qualification testing and has reached production status.
Rev. 3.0
July 2007
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, [phone]
http://www.ramtron.com
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