GENERAL DESCRIPTION

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.

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 (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)

APPLICATIONS

Remote Systems

Battery-Backed Systems

Telecom Switches

Office Equipment

Consumer Electronics

Underwriters Laboratories (UL) Recognized