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