DS1511

DS1501/DS1511 Y2K-Compliant Watchdog Real-Time Clocks www.maxim-ic.com GENERAL DESCRIPTION The DS1501/DS1511 are full-function, year 2000compliant real-time clock/calendars (RTCs) with an RTC alarm, watchdog timer, power-on reset, battery monitors, 256 bytes NV SRAM, and a 32.768kHz output. User access to all registers within the DS1501/DS1511 is accomplished with a byte-wide interface, as shown in Figure 8. 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 +3.3 or +5V Operation Precision Power-On Reset Power-Control Circuitry Support System PowerOn from Date/Day/Time Alarm or Key Closure/Modem-Detect Signal 256 Bytes Battery-Backed NV SRAM Auxiliary Battery Input Accuracy of DS1511 Better than ±1 Minute/Month at +25°C Day-of-Week/Date Alarm Register Crystal Select Bit Allow RTC to Operate with 6pF or 12.6pF Crystal Battery Voltage-Level Indicator Flags Available as Chip (DS1501) or Stand-Alone Module with Embedded Battery and Crystal (DS1511) UL Recognized § § § § § § § § § § § § § APPLICATIONS Remote Systems Battery-Backed Systems Telecom Switches Office Equipment Consumer Electronics ORDERING INF...