DESCRIPTION
The M48T129Y/V TIMEKEEPER RAM is a 128Kb x 8 non-volatile static RAM and real time clock, with programmable alarms and a watchdog timer. The special DIP package provides a fully integrated battery back-up memory and real time clock solution. The M48T129Y/V directly replaces industry standard 128Kb x 8 SRAM. It also provides the non-volatility of Flash without any requirement for special write timing or limitations on the number of writes that can be performed.

■ 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: 4.2V ≤ VPFD ≤ 4.5V
    – M48T129V: 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
■ SURFACE MOUNT CHIP SET PACKAGING INCLUDES a 44-PIN SOIC and a 32-LEAD TSOP (SNAPHAT TOP TO BE ORDERED SEPARATELY)
■ SOIC PACKAGE PROVIDES DIRECT CONNECTION for a SNAPHAT TOP WHICH CONTAINS the BATTERY and CRYSTAL
■ SNAPHAT® HOUSING (BATTERY/CRYSTAL) IS REPLACEABLE