DESCRIPTION nThe DS1746 is a full-function, year-2000-compliant (Y2KC), real-time clock/calendar (RTC) and 128k x 8 nonvolatile static RAM. User access to all registers within the DS1746 is accomplished with a byte-wide interface as shown in Figure 1. The RTC information and control bits reside in the eight uppermost RAM locations. The RTC registers contain century, year, month, date, day, hours, minutes, and seconds data in 24-hour binary-coded decimal (BCD) format. Corrections for the date of each month and leap year are made automatically.nFEATURES nIntegrated NV SRAM, Real-Time Clock, Crystal, Power-Fail Control Circuit, and Lithium Energy Source nClock Registers are Accessed Identically to the Static RAM. These Registers are Resident in the Eight Top RAM Locations. nCentury Byte Register (i.e., Y2K Compliant) nTotally Nonvolatile with Over 10 Years of Operation in the Absence of Power nBCD-Coded Century, Year, Month, Date, Day, Hours, Minutes, and Seconds with Automatic Leap Year Compensation Valid Up to the Year 2100 nBattery Voltage-Level Indicator Flag nPower-Fail Write Protection Allows for ±10% VCC Power Supply Tolerance nLithium Energy Source is Electrically Disconnected to Retain Freshness Until Power is Applied for the First Time nDIP Module Only Standard JEDEC Byte-Wide 128k x 8 Static RAM Pinout nPowerCap Module Board Only n Surface Mountable Package for Direct Connection to PowerCap Containing Battery and Crystal n Replaceable Battery (PowerCap) n Power-On Reset Output n Pin-for-Pin Compatible with Other Densities of DS174xP Timekeeping RAM nAlso Available in Industrial Temperature Range: -40°C to +85°C nUnderwriters Laboratories (UL) Recognized
