FM25L256B
256Kb FRAM Serial 3V Memory
Features
256K bit Ferroelectric Nonvolatile RAM
• Organized as 32,768 x 8 bits
• Unlimited Read/Write Cycles
• 45 Year Data Retention
• NoDelay™ Writes
• Advanced High-Reliability Ferroelectric Process
Write Protection Scheme
• Hardware Protection
• Software Protection
Low Power Consumption
• Low Voltage Operation 2.7V – 3.6V
Industry Standard Configurations
• Industrial Temperature -40°C to +85°C
• 8-pin SOIC and 8-pin TDFN Packages
• “Green”/RoHS Packaging
D
E
D S
N N
E G
M SI 2
M E V0
O D 25
C
E W e: FM
R E ti v
T N rna
O R lte
N O A
F
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 FM25L256B 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 45
years while eliminating the complexities, overhead,
and system level reliability problems caused by
EEPROM and other nonvolatile memories.
Unlike serial EEPROMs, the FM25L256B performs
write operations at bus speed. No write delays are
incurred. Data is written to the memory array
immediately after each byte has been transferred to
the device. The next bus cycle may commence
without the need for data polling. In addition, the
product offers virtually unlimited write endurance.
FRAM also exhibits much lower power consumption
than EEPROM.
These capabilities make the FM25L256B 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 FM25L256B provides substantial benefits to
users of serial EEPROM as a hardware drop-in
replacement. The FM25L256B 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.
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. 3.1
Oct. 2009
Pin Configuration
CS
1
8
VDD
SO
2
7
HOLD
WP
3
6
VSS
4
5
SCK
SI
1
8
2
7
3
6
4
5
/CS
SO
/WP
VSS
VDD
/HOLD
SCK
SI
Top View
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 (2.7 to 3.6V)
Ground
Ordering Information
FM25L256B-G*
FM25L256B-GTR*
“Green”/RoHS 8-pin SOIC
“Green”/RoHS 8-pin SOIC
in Tape & Reel
FM25L256B-DG*
“Green”/RoHS 8-pin TDFN
FM25L256B-DGTR* “Green”/RoHS 8-pin TDFN
in Tape & Reel
* End of life. Last time buy Nov. 2009.
Ramtron International Corporation
1850 Ramtron Drive, Colorado Springs, CO 80921
(800) 545-FRAM, (719) 481-7000
http://www.ramtron.com
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