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

Applications
    Embedded Systems
    Utility Meters
    Security Systems
    Network Hubs, Bridges, and Routers