DESCRIPTION
The X25138 is a CMOS 128K-bit serial E2PROM, internally organized as 16K x 8. The X25138 features a Serial Peripheral Interface (SPI) and software protocol allowing operation on a simple three-wire bus. The bus signals are a clock input (SCK) plus separate data in (SI) and data out (SO) lines. Access to the device is controlled through a chip select (CS) input, allowing any number of devices to share the same bus.

FEATURES
• 5MHz Clock Rate
• Low Power CMOS
    <1mA Standby Current
    <5mA Active Current
• 2.5V To 5.5V Power Supply
• SPI Modes (0,0 & 1,1)
• 16K X 8 Bits
    32 Byte Page Mode
• Block Lock™ Protection
    Protect 1/4, 1/2 or all of E2PROM Array
• Programmable Hardware Write Protection
    In-Circuit Programmable ROM Mode
• Built-in Inadvertent Write Protection
    Power-Up/Down protection circuitry
    Write Enable Latch
    Write Protect Pin
• Self-Timed Write Cycle
    5ms Write Cycle Time (Typical)
• High Reliability
    Endurance: 100,000 cycles
    Data Retention: 100 Years
    ESD protection: 2000V on all pins
• Packages
    8-Lead XBGA
    8, 14-Lead SOIC
    8-Lead PDIP
    8-Lead TSSOP