DS1500

DS1500 Y2K Watchdog RTC with Nonvolatile Control www.maxim-ic.com GENERAL DESCRIPTION The DS1500 is a full-function, year 2000-compliant real-time clock/calendar (RTC) with an alarm, watchdog timer, power-on reset, battery monitors, 256 bytes of on-board nonvolatile (NV) SRAM, NV control for backing up an external SRAM, and a 32.768kHz output. User access to all registers within the DS1500 is accomplished with a byte-wide interface, as shown in Figure 7. The RTC registers contain century, year, month, date, day, hours, minutes, and seconds data in 24-hour binary-coded decimal (BCD) format. Corrections for day of month and leap year are made automatically. FEATURES § BCD-Coded Century, Year, Month, Date, Day, Hours, Minutes, and Seconds with Automatic Leap-Year Compensation Valid Up to the Year 2100 Programmable Watchdog Timer and RTC Alarm Century Register; Y2K-Compliant RTC Automatic Battery Backup and Write Protection to External SRAM +5V Operation Precision Power-On Reset Power-Control Circuitry Supports System PowerOn from Date/Day/Time Alarm or Key Closure 256 Bytes User NV RAM Auxiliary Battery Input Accuracy Better than ±1 Minute/Month at +25°C Day-of-Week/Date Alarm Register Battery Voltage-Level Indicator Flags Industrial Temperature Range: -40°C to +85°C § § § § § § § § § § § § APPLICATIONS Remote Systems Battery-Backed Systems Telecom Switches Office Equipment Consumer Electronics ORDERING INFORMATION PART DS1500YEN DS1500WEN TEMP RANGE -40°C to +85°C -40°C to...