DETAILED DESCRIPTION
The DS1685/DS1687 are real-time clocks (RTC) designed as successors to the industry-standard DS1285, DS1385, DS1485, and DS1585 PC RTCs. These devices provide the industry-standard DS1285 clock function with either +3.0V or +5.0V operation. The DS1685 also incorporates a number of enhanced features including a silicon serial number, power-on/off control circuitry, 242 bytes of user NV SRAM, and 32.768kHz output for sustaining power management activities.

FEATURES
Incorporates Industry-Standard DS1287 PC Clock plus Enhanced Features Such as: Y2K Compliant
■ +3V or +5V Operation
■ 64-Bit Silicon Serial Number
■ Power-Control Circuitry Supports System Power-On from Date/Time Alarm or Key Closure
■ 32kHz Output for Power Management
■ Crystal-Select Bit Allows RTC to Operate with 6pF or 12.5pF Crystal
■ SMI Recovery Stack
■ 242 Bytes Battery-Backed NV RAM
■ Auxiliary Battery Input
■ RAM Clear Input
■ Century Register
■ Date Alarm Register
■ Compatible with Existing BIOS for Original DS1287 Functions
■ Available as Chip (DS1685) or Stand-Alone Encapsulated DIP (EDIP) with Embedded Battery and Crystal (DS1687)
■ Timekeeping Algorithm Includes Leap-Year Compensation Valid Through 2099
■ Underwriters Laboratory (UL) Recognized

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