DS1744-70

Real Time Clock Overview

The DS1744-70 is a Y2K-compliant, nonvolatile timekeeping RAM IC integrating a real-time clock/calendar and 32k x 8 SRAM. It operates on a single 5V supply within the commercial temperature range of 0°C to +70°C. The device utilizes a byte-wide parallel interface where RTC registers occupy the top eight memory locations (7FF8h–7FFFh). Key features include automatic leap-year compensation up to 2100, power-fail write protection, and an integrated lithium battery source providing over 10 years of data retention. The component is housed in a 28-pin encapsulated DIP (EDIP) package.

Real Time Clock Feature Summary

• Integrated NV SRAM with 32k x 8 capacity and standard JEDEC pinout
• Y2K-compliant RTC with BCD-coded century, year, month, date, day, hours, minutes, and seconds
• Automatic leap-year compensation valid through the year 2100
• Power-fail write protection circuitry ensuring data integrity during voltage drops

Real Time Clock Applications

• Industrial control systems requiring precise timekeeping
• Data logging equipment needing nonvolatile storage
• Embedded systems with Y2K compliance requirements
• Battery-backed memory applications

Real Time Clock Procurement Notes

Verify the specific suffix for the required temperature grade; the base model 'DS1744-70' denotes the commercial range (0°C to +70°C), while 'IND' indicates industrial (-40°C to +85°C). Confirm RoHS compliance status via the '+' suffix if applicable. Check current availability as this component may be subject to end-of-life status or limited distribution channels.

Real Time Clock Selection Notes

Select the DS1744-70 for 5V parallel interface designs requiring integrated timekeeping and memory. Ensure the system supports the 28-pin EDIP form factor. For surface-mount compatibility with external batteries, consider the PowerCap variant (DS1744P). Verify that the application environment remains within the specified 0°C to +70°C operating range for this specific part number.

Real Time Clock Part Context

The DS1744 series belongs to Maxim Integrated's family of Y2K-compliant nonvolatile timekeeping RAMs. It is functionally compatible with other densities in the DS174xP series. The device combines silicon, crystal, and lithium energy source into a single module, simplifying PCB layout by eliminating discrete components typically required for RTC and backup power circuits.

Real Time Clock Replacement Considerations

Direct pin-for-pin replacements within the same density include the DS1744-70IND+ for industrial temperature ranges. Other densities in the DS174x family are also pin-compatible but require verification of memory size differences.