DS17887-5IND+

Real Time Clock Overview

The DS17887-5IND+ is a real-time clock (RTC) IC from the DS17x87 series, manufactured by Analog Devices Inc./Maxim Integrated. It integrates a quartz crystal and lithium energy source within a 24-pin encapsulated DIP (EDIP) package. The device provides a multiplexed byte-wide interface for accessing timekeeping registers and 8192 bytes of battery-backed nonvolatile SRAM. It supports both +3.0V and +5.0V operation, with the '-5' suffix indicating the +5.0V variant. The industrial temperature range (-40°C to +85°C) ensures reliable performance in demanding environments.

Real Time Clock Feature Summary

• Integrates a 32.768kHz quartz crystal and lithium coin cell battery in a single 24-pin EDIP package
• Provides 8192 bytes of extended battery-backed NV SRAM alongside standard RTC functions
• Supports system power-on via external stimulus or time-and-date alarm through PWR output pin
• Includes automatic leap year compensation through 2099 and dual voltage supply monitoring

Real Time Clock Applications

• Embedded systems requiring precise timekeeping and data retention
• Utility meters needing long-term battery backup capabilities
• Security systems with wake-up alarm functionality
• Network hubs, bridges, and routers for timestamping events

Real Time Clock Procurement Notes

Verify the specific ordering suffix '-5IND+' corresponds to the +5.0V VCC supply range and industrial temperature grade (-40°C to +85°C). Confirm that the EDIP package type matches the design requirements, as it contains an integrated lithium energy source sensitive to soldering temperatures. Ensure the primary power supply remains above the power-fail threshold during normal operation to maintain full accessibility.

Real Time Clock Selection Notes

Select this component when an integrated crystal and battery solution is preferred over discrete components. The DS17887 variant is chosen specifically for its 8KB extended RAM capacity, distinguishing it from the 114-byte RAM versions like the DS12887. Verify compatibility with the host system's multiplexed bus interface timing requirements and ensure the +5.0V logic levels align with the microcontroller's input specifications.

Real Time Clock Part Context

This part belongs to the DS17x87 family, which serves as a successor to the industry-standard DS12887. Unlike the DS17x85 variants that require external crystals and batteries, the DS17x87 models integrate these elements into the EDIP package. The DS17887 specifically offers the highest memory capacity (8KB) within this integrated series, providing enhanced storage for application data while maintaining standard RTC features.

Real Time Clock Replacement Considerations

The DS12887+ is a direct functional replacement for basic timekeeping needs but lacks the 8KB extended RAM found in the DS17887. If the additional memory is not required, the DS12887 can be used, though software must be adjusted to ignore the extended RAM addresses. Both devices share similar pinouts and control register structures.