Description
The M48T129Y/V TIMEKEEPER® RAM is a 128 Kb x 8 non-volatile static RAM and realtime clock with programmable alarms and a watchdog timer.
   
Features
■ Integrated, ultra low power SRAM, real-time
    clock, power-fail control circuit, battery, and
    crystal
■ BCD coded century, year, month, day, date,
    hours, minutes, and seconds
■ Battery low warning flag
■ Automatic power-fail chip deselect and WRITE
    protection
■ Two WRITE protect voltages:
    (VPFD = power-fail deselect voltage)
    – M48T129Y: VCC = 4.5 to 5.5 V;
        4.2 V ≤ VPFD ≤ 4.5 V
    – M48T129V: VCC = 3.0 to 3.6 V;
        2.7 V ≤ VPFD ≤ 3.0 V
■ Conventional SRAM operation; unlimited
    WRITE cycles
■ Software controlled clock calibration for high
    accuracy applications
■ 10 years of data retention and clock operation
    in the absence of power
■ Self-contained battery and crystal in DIP
    package
■ Microprocessor power-on reset
    (valid even during battery backup mode)
■ Programmable alarm output active in battery
    backup mode
■ RoHS compliant
    – Lead-free second level interconnect