Summary description
The M48T35/Y TIMEKEEPER® RAM is a 32Kb x 8 non-volatile static RAM and real time clock. The monolithic chip is available in two special packages to provide a highly integrated battery backed-up memory and real time clock solution. The M48T35/Y is a non-volatile pin and function equivalent to any JEDEC standard 32Kb x 8 SRAM. It also easily fits into many ROM,EPROM, and EEPROM sockets, providing the non-volatility of PROMs without any requirement for special WRITE timing or limitations on the number of WRITEs that can be performed.
The 28-pin, 600mil DIP CAPHAT houses the M48T35/Y silicon with a quartz crystal and a long life lithium button cell in a single package.

FEATUREs
■ Integrated, ultra low power SRAM, real time clock, power-fail control circuit and battery
■ BYTEWIDE™ RAM-like clock access
■ BCD coded year, month, day, date, hours, minutes, and seconds
■ Frequency test output for real time clock
■ Automatic power-fail chip deselect and WRITE protection
■ WRITE protect voltages(VPFD= Power-fail Deselect Voltage):
    –M48T35: VCC= 4.75 to 5.5V
    –4.5V ≤VPFD ≤4.75V
    –M48T35Y: VCC= 4.5 to 5.5V
    –4.2V ≤ VPFD ≤ 4.5V
■ Self-contained battery and crystal in the CAPHAT™ DIP package
■ SOIC package provides direct connection for a SNAPHAT® housing containing the battery and
crystal
■ SNAPHAT® housing (battery and crystal) is replaceable
■ Pin and function compatible with JEDEC standard 32 Kb x 8 SRAMs
■ RoHS compliant
    – Lead-free second level interconnect