Y2K-Compliant Watchdog Real-Time Clocks

The DS1501/DS1511 are full-function, year 2000-compliant 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.

Applications

* Battery-Backed Systems * Consumer Electronics * Office Equipment * Remote Systems * Telecom Switches

* 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 (W) or +5V (Y) Operation

* Precision Power-On Reset

* Power-Control Circuitry Support System Power-On from Date/Day/Time Alarm or Key Closure/Modem-Detect Signal

* 256 Bytes Battery-Backed 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 (DS1501)

* Battery Voltage-Level Indicator Flags

* Available as Chip (DS1501) or Stand-Alone Encapsulated DIP Module with Embedded Battery and Crystal (DS1511)