DS1678S

Real Time Clock Overview

The DS1678S is a Real-Time Clock (RTC) event recorder manufactured by Analog Devices Inc./Maxim Integrated. It logs the time and date of nonperiodic, asynchronous events triggered by the INT pin. The device features a BCD RTC/calendar with leap-year compensation, 32 bytes of battery-backed NV RAM, and an I²C serial interface. It supports logging up to 1025 consecutive events in read-only memory using a 16-bit elapsed time counter. Operating voltage ranges from 4.5 V to 5.5 V for VCC and 2.6 V to 3.5 V for VBAT. It operates within an industrial temperature range of -40°C to +85°C and is housed in an 8-pin SO package.

Real Time Clock Feature Summary

• Logs up to 1025 consecutive events in read-only battery-backed memory
• I²C serial interface for communication
• Programmable event trigger via INT pin rising/falling edges
• 32-byte general-purpose NV RAM

Real Time Clock Applications

• Real-time event recording systems
• Portable system controllers requiring timestamping
• Industrial monitoring applications

Real Time Clock Procurement Notes

Verify component authenticity through authorized distributors. Confirm RoHS compliance status as indicated by the '+' suffix. Check current availability as supply may be restricted. Ensure ordering suffixes match required packaging formats such as tape and reel or tube.

Real Time Clock Selection Notes

Select based on I²C interface compatibility and power supply requirements. Consider the three resolution options for the elapsed time counter to balance accuracy against maximum time between events. Verify that the 8-pin SO package fits the design constraints. Ensure external crystal specifications meet the 12.5 pF load capacitance requirement.

Real Time Clock Part Context

The DS1678S belongs to the DS1678 series of real-time clocks. It is part of the broader portfolio of Maxim Integrated RTCs designed for portable and industrial applications. The 'S' suffix denotes the SO package variant. Other variants include DIP packages and different speed grades within the same functional family.

Real Time Clock Replacement Considerations

Consult official documentation for direct substitutes. Cross-reference pinouts and electrical characteristics carefully. Verify compatibility with existing I²C bus protocols and memory maps before replacement.