DS1643

The DS1643 is an 8K x 8 nonvolatile static RAM with a full function real time clock which are both accessible in a bytewide format.The nonvolatile time keeping RAM is pin and functionequivalent to any JEDEC standard 8K x 8 SRAM.

Features of the DS1643 are:(1)form, fit and function compatible with the MK48T08 timekeeping RAM; (2)integrated NV SRAM, real time clock, crystal, power-fail control circuit and lithium ennergy source; (3)standard JEDEC bytewide 8K x 8 static RAM pinout; (4)access time of 120 ns and 150 ns ; (5)BCD coded year, month, date, hours, minutes, and seconds; (6)power-fail write protection allows for ±10% Vcc power suppy tolerance.

The absolute maximum ratings of the DS1643 can be summarized as:(1): voltage on any pin relative to ground is -0.3 V to 7.0 V; (2): operating temprature is 0 to 70; (3): storage temperature is -20 to 70; (4): soldering temperature is 260 for 10 seconds.