Description The M48T37Y/V TIMEKEEPER® RAM is a 32 Kb x 8 non-volatile static RAM and real-time clock. The monolithic chip is available in a special package which provides a highly integrated battery-backed memory and real-time clock solution. The 44-lead, 330 mil SOIC package 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. Features ■ Integrated ultra low power SRAM, real-time clock, power-fail control circuit, and battery ■ Frequency test output for real-time clock software calibration ■ Automatic power-fail chip deselect and WRITE protection ■ Watchdog timer ■ WRITE protect voltage(VPFD= Power-fail deselect voltage): –M48T37Y: VCC= 4.5 to 5.5 V 4.2 V ≤VPFD ≤4.5 V –M48T37V: VCC= 3.0 to 3.6 V 2.7 V ≤VPFD ≤3.0 V ■ Packaging includes a 44-lead SOIC and SNAPHAT®top (to be ordered separately) ■ SOIC package provides direct connection for a SNAPHAT®top which contains the battery and crystal ■ Microprocessor power-on reset (valid even during battery backup mode) ■ Programmable alarm output active in the battery backup mode ■ Battery low flag ■ RoHS compliant – Lead-free second level interconnect