Y2K-Compliant Watchdog RTC with NV Control

 

Part Number	Replacement	Explanation

Description

Create a design and simulate using EE-Sim^® tools:

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.

DS1500: Typical Operating Circuit Enlarge+

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