DS1500

· 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 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
· Industrial Temperature Range: -40°C to +85°C

Voltage Range on Any Pin Relative to Ground ...............-0.5V to +6.0V
Operating Temperature Range ......................-40°C to +85°C (Note 1)
Storage Temperature Range .....................................-55°C to +125°C
Soldering Temperature ..........See IPC/JEDEC J-STD-020A Specification

Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to the absolute maximum rating conditions for extended periods may affect device.

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.