DS1744-70+

Real Time Clock Overview

The DS1744-70+ is a Y2K-compliant, nonvolatile timekeeping RAM IC integrating a real-time clock/calendar (RTC), 32k x 8 NV SRAM, crystal, and lithium energy source. It operates at 5V with a commercial temperature range of 0°C to +70°C. The device uses a standard JEDEC byte-wide 32k x 8 static RAM pinout in a 28-pin encapsulated DIP (EDIP) package. RTC registers reside in the top eight RAM locations, providing century, year, month, date, day, hours, minutes, and seconds data in BCD format with automatic leap-year compensation.

Real Time Clock Feature Summary

• Integrated NV SRAM, RTC, crystal, power-fail control circuit, and lithium battery
• Y2K compliant with century byte register and automatic leap-year compensation valid to 2100
• Standard JEDEC 32k x 8 static RAM pinout for direct replacement
• Power-fail write protection ensures data integrity during supply voltage anomalies

Real Time Clock Applications

• Industrial systems requiring precise timekeeping and nonvolatile data storage
• Embedded controllers needing Y2K-compliant calendar functions
• Equipment requiring long-term data retention without external batteries

Real Time Clock Procurement Notes

Verify the specific suffix '+', which indicates a lead-free/RoHS-compliant package. Confirm the operating temperature grade matches the application requirements; this model is rated for commercial temperatures (0°C to +70°C). Ensure the system design accommodates the 28-pin EDIP through-hole mounting style and provides appropriate VCC supply stability.

Real Time Clock Selection Notes

Select the DS1744-70+ when a 5V supply and commercial temperature range are sufficient. For industrial applications (-40°C to +85°C), choose the DS1744-70IND+. If surface-mount assembly is required with an external PowerCap module, consider the DS1744P variant. Verify that the host microcontroller supports the parallel interface timing specifications.

Real Time Clock Part Context

The DS1744 series includes variants like the DS1744P (PowerCap module) and different speed grades. The DS1744-70+ specifically denotes the 70ns access time version in the 28-pin EDIP package. It is part of a family designed to replace older discrete RTC and battery backup solutions with a single integrated component.

Real Time Clock Replacement Considerations

Pin-for-pin compatible with other densities of the DS174xP timekeeping RAM family. Ensure the replacement part number matches the required temperature range and voltage specifications.