DS1685SN-5+

Real Time Clock Overview

The DS1685SN-5+ is a real-time clock (RTC) IC designed as a successor to the industry-standard DS1287. It provides timekeeping and calendar functions with Y2K compliance, operating on a +5V supply within a 0°C to +70°C temperature range. The device features a multiplexed address/data bus interface and includes 242 bytes of battery-backed nonvolatile SRAM. Key enhancements include a 64-bit silicon serial number, power-control circuitry for system wake-up, and a 32kHz square-wave output. It supports both 12-hour and 24-hour time formats with automatic leap-year compensation valid through 2099.

Real Time Clock Feature Summary

• Incorporates industry-standard DS1287 PC clock functionality with Y2K compliance
• Includes 242 bytes of battery-backed NV SRAM and a 64-bit silicon serial number
• Features power-control circuitry allowing system power-on via date/time alarm or key closure
• Provides a 32kHz square-wave output for power management activities

Real Time Clock Applications

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

Real Time Clock Procurement Notes

Verify that the specific ordering suffix 'SN' corresponds to the SOIC package variant in official documentation, as datasheets list 'DS1685S' for SO packages. Confirm lead-free/RoHS compliance indicated by the '+' suffix. Check current manufacturing status as older Maxim Integrated RTCs may have end-of-life designations.

Real Time Clock Selection Notes

Select this model for systems requiring a direct replacement for legacy DS1287 designs with enhanced NV RAM capacity. Ensure the application utilizes a +5V primary supply and requires a multiplexed parallel interface. Verify that the 0°C to +70°C commercial temperature range meets environmental requirements, as industrial grades (-40°C to +85°C) are available under different part numbers.

Real Time Clock Part Context

The DS1685 series serves as an enhanced successor to earlier Dallas Semiconductor/Maxim RTCs like the DS1285 and DS1385. The 'SN' designation typically indicates the SOIC package form factor within the DS1685 family. This component bridges legacy PC clock architectures with modern nonvolatile memory needs, offering extended features such as auxiliary battery inputs and kickstart capabilities not present in original counterparts.

Real Time Clock Replacement Considerations

Direct pin-compatible replacements include other variants within the DS1685 family, such as DS1685S-5+ for SOIC packages. For industrial temperature ranges, consider DS1685S-5IND+. Legacy equivalents like the DS1287 remain functionally similar but lack the enhanced NV RAM and serial number features.