DS1743-85+

Real Time Clock Overview

The DS1743-85+ is a Y2K-compliant, nonvolatile timekeeping RAM integrating an 8k x 8 static RAM and a real-time clock/calendar. It operates at 5V with a commercial temperature range of 0°C to +70°C in a 28-pin EDIP module. The device features BCD-coded time/date registers with automatic leap year compensation through 2099. Internal lithium battery backup ensures data retention for over 10 years without power. Power-fail write protection prevents data corruption during supply voltage anomalies.

Real Time Clock Feature Summary

• Integrated NV SRAM (8k x 8) and RTC with century byte register
• Automatic leap year compensation valid through 2099
• Power-fail write protection with ±10% VCC tolerance
• Lithium energy source electrically disconnected until first power application

Real Time Clock Applications

• Redundant power supplies requiring time-stamped logging
• Telecommunications infrastructure equipment
• Industrial control systems needing nonvolatile date/time tracking

Real Time Clock Procurement Notes

Verify the specific suffix '-85+' corresponds to the 5V commercial grade (0°C to +70°C). Confirm the package type matches the required system design, as the 'P' variant denotes a separate PowerCap board interface rather than the integrated DIP module. Ensure the ordering suffix aligns with lead-free/RoHS compliance requirements specified in the datasheet.

Real Time Clock Selection Notes

Select the DS1743-85+ for 5V logic interfaces requiring a fully encapsulated 28-pin DIP solution. Choose the industrial grade (-100 IND+) if operation below 0°C is necessary. Verify that the system does not require the surface-mountable PowerCap configuration, which necessitates a separate DS9034PCX component for the crystal and battery.

Real Time Clock Part Context

This component belongs to the DS174XP family of timekeeping RAMs. It offers pin-for-pin compatibility with other densities in the series, allowing for density upgrades or downgrades without PCB redesign. The device replaces older discrete RTC and SRAM solutions by consolidating functionality into a single monolithic module.

Real Time Clock Replacement Considerations

Pin-compatible alternatives within the DS174XP family include the DS1742 and DS1744, which offer different memory densities while maintaining identical RTC register mappings and physical footprints.