DS17487-5

Real Time Clock Overview

The DS17487-5+ is a standalone real-time clock (RTC) module manufactured by Analog Devices / Maxim Integrated. It integrates a quartz crystal and lithium energy source within an EDIP-24 package, eliminating the need for external components. The device operates on a +5V supply (4.5V to 5.5V) and features a multiplexed byte-wide interface. Key specifications include 4096 bytes of battery-backed NV SRAM, leap-year compensation through 2099, and a 64-bit silicon serial number. It supports system power-on via date/time alarms or key closures.

Real Time Clock Feature Summary

• Integrated quartz crystal and lithium battery in EDIP-24 package
• 4096 bytes of extended battery-backed NV SRAM plus 114 bytes user RAM
• Multiplexed address/data bus interface with +5V operation
• Power-control circuitry for wake-up from alarm or kickstart input

Real Time Clock Applications

• Embedded systems requiring autonomous timekeeping
• Utility meters needing nonvolatile data retention
• Security systems with power-fail detection
• Network hubs, bridges, and routers

Real Time Clock Procurement Notes

Verify the specific ordering suffix (+5 vs +3) to ensure compatibility with the target system voltage, as the DS17487 series offers both +3V and +5V variants. Confirm that the EDIP-24 through-hole package aligns with the PCB layout constraints. Check current availability status, as this component may be subject to limited supply conditions.

Real Time Clock Selection Notes

Select the DS17487-5+ when a +5V logic interface is required alongside integrated power sources. This model provides 4096 bytes of extended RAM, distinguishing it from the DS17287 (2048 bytes) and DS17887 (8192 bytes). Ensure the application utilizes the multiplexed bus architecture compatible with industry-standard PC clock designs.

Real Time Clock Part Context

The DS17487-5+ belongs to the DS17x87 family, designed as successors to the DS12887. Unlike the DS17x85 chips which require external crystals and batteries, the DS17x87 modules encapsulate these elements. The -5 suffix denotes the +5V operating voltage range, while the '+' indicates RoHS compliance.

Real Time Clock Replacement Considerations

Direct replacements within the same family include DS17487-3+ for +3V applications. For different memory capacities, consider DS17287-5+ (2kB extended RAM) or DS17887-5+ (8kB extended RAM). Non-integrated equivalents like DS17485-5+ require external crystal and battery connections.