DS1554W-120IND

Real Time Clock Overview

The DS1554W-120IND+ is a Y2K-compliant real-time clock/calendar integrated with 32k x 8 nonvolatile static RAM. It operates at 3.3V and features an industrial temperature range of -40°C to +85°C. The device includes an internal lithium energy source, crystal, and power-fail control circuit within a 32-pin EDIP package. Clock registers reside in the top 16 RAM locations and are accessed via a parallel byte-wide interface. It provides programmable watchdog timer and alarm functions, automatic leap-year compensation up to 2100, and battery voltage-level indication.

Real Time Clock Feature Summary

• Integrated NV SRAM (32k x 8), RTC, crystal, and lithium battery
• Y2K compliant with BCD-coded time/date and automatic leap-year correction
• Programmable watchdog timer and RTC alarm with interrupt output
• Power-fail write protection and precision power-on reset

Real Time Clock Applications

• Industrial systems requiring nonvolatile timekeeping
• Battery-backed data logging applications
• Embedded controllers needing precise calendar functions

Real Time Clock Procurement Notes

Verify the specific suffix IND+ confirms the industrial temperature grade (-40°C to +85°C) and lead-free status. Confirm the 32-pin EDIP package matches the target footprint. Ensure the 3.3V supply requirement aligns with system design constraints before procurement.

Real Time Clock Selection Notes

Select this model for 3.3V parallel interface designs requiring integrated battery backup. Compare against the 5V DS1554 variants if higher voltage tolerance is needed. Consider the PowerCap module option if surface-mount assembly without thermal damage to the internal battery is required.

Real Time Clock Part Context

This component belongs to the DS1554 family of nonvolatile timekeeping RAMs. It shares functional similarities with the DS1553 but offers larger memory capacity. The 'W' suffix denotes the 3.3V operating voltage, while 'IND' indicates the extended temperature range suitable for harsh environments.

Real Time Clock Replacement Considerations

Direct replacements include other DS1554 variants with different voltage ratings or packages, such as DS1554P-70IND+. Verify pin compatibility and voltage levels when substituting.