Description
The M41T315Y/V/W RTC Supervisor is a combination of a CMOS TIMEKEEPER® and a nonvolatile memory supervisor. Power is constantly monitored by the memory supervisor. In the event of power instability or absence, an external battery maintains the timekeeping operation and provides power for a CMOS static RAM by switching on and invoking write protection to prevent data corruption in the memory and RTC.

FEATUREs
■ 3.0V, 3.3V, or 5V operating voltage
■ Real-time clock keeps track of tenths/hundredths of seconds, seconds, minutes, hours, days, date of the month, months, and years
■ Automatic leap year correction valid up to 2100
■ Automatic switch-over and deselect circuitry
■ Choice of power-fail deselect voltages: (VPFD = power-fail deselect voltage)
    – M41T315Y(a): VCC = 4.5 to 5.5V 4.25V ≤ VPFD ≤ 4.50V
    – M41T315V: VCC = 3.0 to 3.6V 2.80V ≤ VPFD ≤ 2.97V
    – M41T315W: VCC = 2.7 to 3.3V 2.60V ≤ VPFD ≤ 2.70V
■ No address space required to communicate with RTC
■ Provides nonvolatile supervisor functions for battery backup of SRAM
■ Full ±10% VCC operating range
■ Industrial operating temperature range (–40 to +85°C)
■ Ultra-low battery supply current of 500nA (max)
■ Optional packaging includes A 28-lead SOIC and SNAPHAT® top (to be ordered separately)
■ SNAPHAT package provides direct connection for a snaphat top, which contains the battery and crystal
■ RoHS compliant
    – Lead-free second level interconnect