Maxim Integrated DS1744-70IND+, Real Time Clock, 28-Pin EDIP, Часы реального времени

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 are Resident in the Eight Top RAM Locations.
Century Byte Register (i.e., Y2K Compliant)
Totally Nonvolatile with Over 10 Years of Operation in the Absence of Power
BCD-Coded Century, Year, Month, Date, Day, Hours, Minutes, and Seconds with Automatic Leap-Year Compensation Valid Up to the Year 2100
Battery Voltage-Level Indicator Flag
Power-Fail Write Protection Allows for ±10% VCC Power-Supply Tolerance
Lithium Energy Source is Electrically Disconnected to Retain Freshness Until Power is Applied for the First Time
DIP Module Only
Standard Byte-Wide 32k x 8 Static RAM Pinout
PowerCap Module Board Only
Surface-Mountable Package for Direct Connection to PowerCap Containing Battery and Crystal
Replaceable Battery (PowerCap)
Power-On Reset Output
Pin-for-Pin Compatible with Other Densities of DS174xP Timekeeping RAM
Also Available in Industrial Temperature Range: -40°C to +85°C

Datasheet - DS1744-70IND+