Features: •Save critical data with programmable block lock protection
-Block lock (first page, first 2 pages, first 4 pages, first 8 pages, 1/4, 1/2, or all of EEPROM array)
-Software write protection
-Programmable hardware write protect
•In circuit programmable ROM mode
•400kHz 2-wire serial interface
-Schmitt trigger input noise suppression
-Output slope control for ground bounce noise elimination
•Longer battery life with lower power
-Active read current less than 1µA
-Active write current less than 3µA
-Standby current less than 1µA
•2.5V to 5.5V power supply
•64-byte page write mode
-Minimizes total write time per word
•Internally organized 32K x 8
•Bidirectional data transfer protocol
•Self-timed write cycle
-Typical write cycle time of 5ms
•High reliability
-Endurance: 100,000 cycles
-Data retention: 100 years
•8-lead XBGA, 8-lead SOIC, 14-lead TSSOPPinout
SpecificationsTemperature under bias...................65°C to +135°C
Storage temperature........................65°C to +150°C
Voltage on any pin with
respect to VSS.........................................1V to +7V
D.C.output current...............................................5mA
Lead temperature
(soldering, 10 seconds)..................................300°CDescriptionThe X24257 is a CMOS Serial EEPROM, internally organized 32K x 8. The device features a serial inter-ace and software protocol allowing operation on a simple two wire bus.
Three device select inputs (S0-S1) allow up to four devices to share a common two wire bus.
A Write Protect Register at the highest address location,FFFFh, provides three write protection features: Software Write Protect, Block Lock Protect, and Programmable Hardware Write Protect. The Software Write Protect eature prevents any nonvolatile writes to the X24257 until the WEL bit in the Write Protect Register is set. The Block Lock Protection feature gives the user eight array block protect options, set by programming three bits in the Write Protect Register. The Programmable Hardware Write Protect feature allows the user to install the device with WP tied to VCC, write to and Block Lock the desired portions of the memory array in circuit, and then enable the In Circuit Programmable OM Mode by programming the WPEN bit HIGH in the Write Protect Register. After this, the Block Locked portions of the array, including the Write Protect Register itself, are protected from being erased if WP is high.
Xicor EEPROMs are designed and tested for applica- tions requiring extended endurance. Inherent data retention is greater than 100 years.
X24257 Data Sheet
