Description:

The M48T58Y TIMEKEEPER®RAM is a 8 Kb x 8 non-volatile static RAM and real-time clock.

The M48T58Y is a non-volatile pin and function equivalent to any JEDEC standard 8b Kb 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, 330 mil 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 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 keyed to prevent reverse insertion. 

The battery/crystal package (e.g., SNAPHAT) part number is “M4T28-BR12SH”.

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):
• M48T58: VCC= 4.75 to 5.5 V; 4.5 V = VPFD= 4.75 V
• M48T58Y: VCC= 4.5 to 5.5 V; 4.2 V = VPFD= 4.5 V
• Self-contained battery and crystal in the CAPHAT™DIP package
• Packaging includes a 28-lead SOIC and SNAPHAT® top (to be ordered separately)
• SOIC package provides direct connection for a snaphat housing containing the battery and crystal
• Pin and function compatible with JEDEC standard 8 Kb x 8 SRAMs
• RoHS compliant