DESCRIPTION
●The DS1643 is an 8K x 8 nonvolatile static RAM with a full function Real Time Clock (RTC) that are both accessible in a byte-wide format. The nonvolatile timekeeping RAM is functionally equivalent to any JEDEC standard 8K x 8 SRAM. The device can also be easily substituted in ROM, EPROM and EEPROM sockets providing read/write nonvolatility and the addition of the real time clock function. The real time clock information resides in the eightuppermost RAM locations.
●FEATURES
●Integrated NV SRAM, Real-Time Clock, Crystal, Power-Fail Control Circuit and Lithium Energy Source
●Clock Registers are Accessed Identically to the Static RAM. These Registers Reside in the Eight Top RAM Locations.
●Totally Nonvolatile with Over 10 Years of Operation in the Absence of Power
●Access Times of 85ns and 100ns
●BCD-Coded Year, Month, Date, Day, Hours, Minutes, and Seconds with Leap Year Compensation Valid Up to 2100
●Power-Fail Write Protection Allows for ±10% VCCPower Supply Tolerance
●Lithium Energy Source is Electrically
●Disconnected to Retain Freshness Until Power is Applied for the First Time
●DS1643 Only (DIP Module)
● Standard JEDEC Byte-Wide 8K x 8 RAM Pinout
●UL Recognized
●DS1643P Only (PowerCap Module Board) Surface Mountable Package for Direct
● Connection to PowerCap Containing
● Battery and Crystal Replaceable Battery (PowerCap) Power-Fail Output
●Pin-for-Pin Compatible with Other Densities of
●DS164XP Timekeeping RAM
