DS1743P-70

Real Time Clock Overview

The DS1743P-70 is a Y2K-compliant, nonvolatile timekeeping RAM integrating an 8k x 8 static RAM and a real-time clock/calendar. It utilizes a bytewide parallel interface with standard JEDEC pinout compatibility. The device features double-buffered BCD-coded registers for century, year, month, date, day, hours, minutes, and seconds, including automatic leap year compensation valid through 2099. It incorporates integrated power-fail control circuitry and a lithium energy source that disconnects electrically until initial power application. The component operates on a single 5V supply within the commercial temperature range of 0°C to +70°C.

Real Time Clock Feature Summary

• Integrated NV SRAM (8KB), RTC, crystal, power-fail control, and lithium battery in a 34-pin PowerCap module
• BCD-coded time/date registers with automatic leap year correction valid through 2099
• Power-fail write protection ensures data integrity during voltage outages
• Lithium energy source remains disconnected until first VCC application to preserve freshness

Real Time Clock Applications

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

Real Time Clock Procurement Notes

Verify package type compatibility, as the DS1743P requires a separate PowerCap module (DS9034PCX+ or DS9034I-PCX+) containing the battery and crystal. Confirm the specific speed grade suffix matches system timing requirements. Check for lead-free status if RoHS compliance is mandatory for the assembly process.

Real Time Clock Selection Notes

Select the DS1743P variant when surface-mount assembly is required before battery installation to avoid thermal damage. Ensure the host system provides a stable 5V supply exceeding the write-protection threshold (VPF) for full accessibility. Verify that the 34-pin PowerCap footprint aligns with the PCB layout constraints.

Real Time Clock Part Context

This component belongs to the DS174x family of nonvolatile timekeeping RAMs. It offers pin-for-pin compatibility with other densities in the series, allowing for design flexibility. The PowerCap packaging distinguishes it from the DIP modules by separating the battery/crystal assembly from the silicon die.

Real Time Clock Replacement Considerations

Direct replacements include other DS1743P variants with different speed grades or industrial temperature ratings. Cross-model substitution within the DS174x family is possible due to pin compatibility, provided memory density and interface timing requirements are met.