19-5480 Rev 8/10 DS1553 64kB, Nonvolatile, Year-2000-Compliant Timekeeping RAM www.maxim-ic.com GENERAL DESCRIPTION FEATURES The DS1553 is a full-function, year-2000- Integrated NV SRAM, RTC, Crystal, Power-Fail Control Circuit, and Lithium Energy Source compliant (Y2KC) real-time clock/calendar (RTC) with an RTC alarm, watchdog timer, power-on Clock Registers are Accessed Identically to the reset, battery monitor, and 8k x 8 nonvolatile static Static RAM These Registers are Resident in the RAM. User access to all registers within the 16 Top RAM Locations DS1553 is accomplished with a byte-wide Totally Nonvolatile with Over 10 Years of interface as shown in Figure 1. The RTC registers Operation in the Absence of Power contain century, year, month, date, day, hours, Precision Power-On Reset minutes, and seconds data in 24-hour BCD format. Programmable Watchdog Timer and RTC Alarm Corrections for day of month and leap year are made automatically. BCD-Coded 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% Pin Configurations appear at end of data sheet. V Power-Supply Tolerance CC Lithium Energy Source is Electrically Disconnected to Retain Freshness Until Power is Applied for the First Time ORDERING INFORMATION PART VOLTAGE (V) TEMP RANGE PIN-PACKAGE TOP MARK** DS1553-85+ 5.0 0C to +70C 28 EDIP (0.740) DS1553+85 DS1553-100+ 5.0 0C to +70C 28 EDIP (0.740) DS1553+100 DS1553W-120+ 3.3 0C to +70C 28 EDIP (0.740) DS1553W+120 DS1553W-150+ 3.3 0C to +70C 28 EDIP (0.740) DS1553W+150 DS1553P-85+ 5.0 0C to +70C 34 PowerCap* DS1553P+85 DS1553P-100+ 5.0 0C to +70C 34 PowerCap* DS1553P+100 DS1553WP-120+ 3.3 0C to +70C 34 PowerCap* DS1553WP+120 DS1553WP-150+ 3.3 0C to +70C 34 PowerCap* DS1553WP+150 DS9034PCX+ 3 0C to +70C DS9034PCX +Denotes a lead(Pb)-free/RoHS-compliant package. *PowerCap required, must be ordered separately **A + symbol anywhere on the top mark indicates a lead(Pb)-free package. Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata. 1 of 20 DS1553 64kB, Nonvolatile, Year-2000-Compliant Timekeeping RAM PIN DESCRIPTION PIN NAME FUNCTION EDIP PowerCap 1 2 RST Active-Low Power-On Reset Output (Open Drain) 2 30 A12 3 25 A7 4 24 A6 5 23 A5 6 22 A4 7 21 A3 8 20 A2 Address Inputs 9 19 A1 10 18 A0 21 28 A10 23 29 A11 24 27 A9 25 26 A8 11 16 DQ0 12 15 DQ1 13 14 DQ2 15 13 DQ3 Data Input/Outputs 16 12 DQ4 17 11 DQ5 18 10 DQ6 19 9 DQ7 20 8 CE Active-Low Chip Enable 22 7 OE Active-Low Output Enable 26 1 IRQ/FT Active-Low Interrupt/Frequency Test Output (Open Drain) 27 6 WE Active-Low Write Enable 28 5 V Power-Supply Input CC 17 GND Ground 2, 3, 3134 N.C No Connection 2 of 20