General Description
The DS17285, DS17485, DS17885, DS17287, DS17487, and DS17887 real-time clocks (RTCs) are designed to be successors to the industry-standard DS12885 and DS12887. The DS17285, DS17485, and DS17885 (hereafter referred to as the DS17x85) provide a real-time clock/calendar, one time-of-day alarm, three maskable interrupts with a common interrupt output, a programmable square wave, and 114 bytes of battery-backed NV SRAM.

FEATUREs
● Incorporates Industry-Standard DS12887 PC Clock Plus Enhanced Functions
● RTC Counts Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation Through 2099
● Optional +3.0V or +5.0V Operation
● SMI Recovery Stack
● 64-Bit Silicon Serial Number
● Power-Control Circuitry Supports System PowerOn from Date/Time Alarm or Key Closure
● Crystal Select Bit Allows Operation with 6pF or 12.5pF Crystal
● 12-Hour or 24-Hour Clock with AM and PM in 12-Hour Mode
● 114 Bytes of General-Purpose, Battery-Backed NV SRAM
● Extended Battery-Backed NV SRAM
    • 2048 Bytes (DS17285/DS17287)
    • 4096 Bytes (DS17485/DS17487)
    • 8192 Bytes (DS17885/DS17887)
● RAM Clear Function
● Interrupt Output with Six Independently Maskable Interrupt Flags
● Time-of-Day Alarm Once per Second to Once per Day
● End of Clock Update Cycle Flag
● Programmable Square-Wave Output
● Automatic Power-Fail Detect and Switch Circuitry
● Available in PDIP, SO, or TSOP Package (DS17285, DS17485, DS17885)
● Optional Encapsulated DIP (EDIP) Package with Integrated Crystal and Battery (DS17287, DS17487, DS17887)
● Optional Industrial Temperature Range Available
● Underwriters Laboratory (UL) Recognized