DS17885E-5

Real Time Clock Overview

The DS17885E-5 is a real-time clock (RTC) and calendar IC from the DS17x85 family, designed as a successor to the DS12885. It provides timekeeping for seconds through years with leap-year compensation through 2099. The device features an 8KB battery-backed NV SRAM, a multiplexed byte-wide interface, and power-control circuitry for system wake-up. It operates on +5.0V or +3.0V supplies, includes a 64-bit silicon serial number, and supports automatic switching to backup power during primary supply failures.

Real Time Clock Feature Summary

• 8KB Battery-Backed NV SRAM
• Multiplexed Byte-Wide Interface
• Leap-Year Compensation Through 2099
• Power-Control Circuitry for System Wake-Up

Real Time Clock Applications

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

Real Time Clock Procurement Notes

Verify the specific package type against the datasheet, as the 'E' suffix typically denotes a TSOP package while other variants use SOIC or PDIP. Confirm the voltage option ('-5' for 5V operation). Check current availability status, as this component series has been subject to discontinuation notices by the manufacturer.

Real Time Clock Selection Notes

Select the DS17885E-5 when 8KB of nonvolatile storage is required alongside RTC functions. Ensure the design accommodates the multiplexed address/data bus timing requirements. Verify that the crystal load capacitance matches the selected Crystal Select Bit setting (6pF or 12.5pF) for accurate timekeeping.

Real Time Clock Part Context

This part belongs to the DS17x85 family, which also includes the DS17285 (2KB RAM) and DS17485 (4KB RAM). These devices are successors to the industry-standard DS12885/DS12887. The DS17x87 variants differ by integrating a quartz crystal and lithium energy source into an encapsulated DIP package.

Real Time Clock Replacement Considerations

The DS12885 is the predecessor model. The DS17285 and DS17485 offer lower memory capacities but share similar interfaces. For integrated crystal/battery solutions, consider the DS17887 EDIP variant.