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Y2K-Compliant Watchdog RTC with NV Control

Product Details

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.

Key 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 or +3.3V Operation
  • Precision Power-On Reset
  • Power-Control Circuitry Supports System Power-On 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
  • Optional Industrial Temperature Range: -40°C to +85°C

Applications/Uses

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

Simplified Block Diagram

DS1500: Typical Operating Circuit DS1500: Typical Operating Circuit Zoom icon

Design & Development

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Additional Resources
Other Watchdog Clocks
RTC Calculator
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Support & Training

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Key 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 or +3.3V Operation
  • Precision Power-On Reset
  • Power-Control Circuitry Supports System Power-On 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
  • Optional Industrial Temperature Range: -40°C to +85°C

Applications/Uses

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

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.

Simplified Block Diagram

DS1500: Typical Operating Circuit DS1500: Typical Operating Circuit Zoom icon

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal