M41T315Y

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.

The clock keeps track of tenths/hundredths of seconds, seconds, minutes, hours, day, date, month, and year information. The last day of the month is automatically adjusted for months with less than 31 days, including leap year correction.

The clock operates in one of two formats: a 12-hour mode with an AM/PM indicator; or  a 24-hour mode

The nonvolatile supervisor supplies all the necessary support circuitry to convert a CMOS RAM to a nonvolatile memory. The M41T315Y/V/W can be interfaced with RAM without leaving gaps in memory.

The M41T315Y/V/W is supplied in a 28-lead SOIC
SNAPHAT® package (which integrates both crystal and battery in a single SNAPHAT top) or a-16 pin SOIC. The 28-pin, 330mil SOIC provides sockets with gold plated contacts at both ends for direct connection to a separate SNAPHAT housing containing the battery and crystal. The unique design allows the SNAPHAT battery/crystal package to be mounted on top of the SOIC package after the completion of the surface mount process.

Insertion of the SNAPHAT housing after reflow prevents potential battery and crystal damage due to the high temperatures required for device surface- mounting. The SNAPHAT housing is also keyed to prevent reverse insertion.

The 28-pin SOIC and battery/crystal packages are shipped separately in plastic anti-static tubes or in Tape & Reel form. For the 28-lead SOIC, the battery/ crystal package (e.g., SNAPHAT) part number is "M4TXX-BR12SH" (see Table 17., page 22).

Caution: Do not place the SNAPHAT battery/crystal top in conductive foam, as this will drain the lithium button-cell battery.