DS1554-70+

Real Time Clock Overview

The DS1554-70+ is a 256k nonvolatile, Y2K-compliant timekeeping RAM integrating an RTC, crystal, and lithium battery. It features 32k x 8 SRAM with BCD-coded registers for century, year, month, date, day, hours, minutes, and seconds, including automatic leap-year compensation up to 2100. Operating at 5.0V within the 0°C to +70°C range, it provides programmable watchdog timer and alarm functions via IRQ/FT and RST outputs. The device ensures data retention for over 10 years in power-off conditions through an internally disconnected lithium source activated upon first power application.

Real Time Clock Feature Summary

• Integrated 32k x 8 NV SRAM with Y2K-compliant RTC and internal lithium energy source
• BCD-coded clock/calendar with automatic leap-year compensation valid until 2100
• Programmable watchdog timer and alarm with interrupt (IRQ/FT) and reset (RST) outputs
• Power-fail write protection and precision power-on reset circuitry

Real Time Clock Applications

• Systems requiring precise timekeeping and nonvolatile data storage during power outages
• Industrial equipment needing watchdog monitoring and system wakeup capabilities
• Y2K-compliant embedded controllers and data loggers

Real Time Clock Procurement Notes

Verify the specific suffix '-70+' indicates the commercial temperature grade (0°C to +70°C) and lead-free status. Confirm the package type matches the design requirements, as this part number corresponds to the 32-pin EDIP module. Ensure the separate PowerCap accessory is not required for this DIP variant, unlike the P-series parts.

Real Time Clock Selection Notes

Select the DS1554-70+ for applications requiring 5V operation and commercial temperature ranges. For industrial environments (-40°C to +85°C), choose the DS1554-70IND+. If surface-mount assembly is preferred without exposing the battery to reflow heat, consider the DS1554P-70+ paired with the DS9034PCX PowerCap module.

Real Time Clock Part Context

The DS1554 series combines real-time clock functionality with substantial nonvolatile memory. The -70+ designation specifies the 5V voltage version in the commercial temperature range packaged in a 32-pin encapsulated DIP (EDIP). This integration simplifies board design by eliminating external crystals and backup batteries.

Real Time Clock Replacement Considerations

The DS1554-70IND+ serves as the direct industrial temperature replacement. For surface-mount needs, the DS1554P-70+ offers equivalent functionality but requires the separate DS9034PCX PowerCap module.