RTC with integrated NVSRAM — what you get in the 24-EDIP module
The DS12C887+ is a parallel-interface real-time clock/calendar from Analog Devices, packing a full timekeeping function (HH:MM:SS in 12/24 hr, YY-MM-DD-dd) plus 113 bytes of NVSRAM into a single 24-pin EDIP through-hole module. It handles alarm, daylight-savings, and leap-year correction on-chip, and outputs a square wave for system timing. The integrated lithium battery-backed SRAM keeps the time and user data alive when main supply drops to 2.5 V–4 V (battery supply range).
Supply and keep-alive — dual-rail design
Main supply runs 4.5 V to 5.5 V; timekeeping current maxes at 15 mA over that range. When the main rail drops, the battery supply (2.5 V–4 V) takes over to retain the NVSRAM and clock registers. That means no external backup battery management — the module handles the switchover internally.
Lifecycle and sourcing — still an active line item
That means it remains a valid BOM entry for new production runs and legacy sustainment alike.