DESCRIPTION
The M48T129Y/V TIMEKEEPER® RAM is a 128 Kb x 8 non-volatile static RAM and real-time clock with programmable alarms and a watchdog timer.
   
FEATURES SUMMARY
■ INTEGRATED, ULTRA LOW POWER SRAM,
    REAL TIME CLOCK, POWER-FAIL
    CONTROL CIRCUIT, BATTERY, AND
    CRYSTAL
■ YEAR 2000 COMPLIANT
■ 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 5.5V
        4.2V ≤ VPFD ≤ 4.5V
    – M48T129V: VCC = 3.0 to 3.6V
        2.7V ≤ VPFD ≤ 3.0V
■ 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 back-up mode)
■ PROGRAMMABLE ALARM OUTPUT
    ACTIVE IN BATTERY BACK-UP MODE
■ SOIC PACKAGE PROVIDES DIRECT
    CONNECTION FOR A SNAPHAT TOP
    WHICH CONTAINS THE BATTERY AND
    CRYSTAL
■ SNAPHAT HOUSING (BATTERY/CRYSTAL)
    IS REPLACEABLE
■ EQUIVALENT SURFACE-MOUNT (SMT)
    SOLUTION REQUIRES A 44-PIN M48T201Y/
    V AND A STAND-ALONE 128K x8 LPSRAM
    (SNAPHAT® Top to be ordered separately)