DS1554P-70IND+

Real Time Clock Overview

The DS1554P-70IND+ is a Y2K-compliant real-time clock and calendar integrated with 32k x 8 nonvolatile static RAM. It operates on a single 5V supply within an industrial temperature range of -40°C to +85°C. The device features a parallel interface, utilizing 15 address lines (A0–A14) and 8 bidirectional data lines (DQ0–DQ7). Key specifications include a maximum active supply current of 75mA at 5V and a typical CMOS standby current of 6mA. The RTC maintains timekeeping for over 10 years using an internal lithium energy source when VCC is absent.

Real Time Clock Feature Summary

• Integrated 32k x 8 NV SRAM with Y2K-compliant RTC, crystal, and lithium battery backup
• Industrial temperature grade (-40°C to +85°C) in a 34-pin PowerCap module package
• Automatic leap-year compensation and BCD-coded time/date registers up to year 2100
• Programmable watchdog timer and alarm with interrupt output (IRQ/FT)
• Power-fail write protection and precision power-on reset circuitry

Real Time Clock Applications

• Data logging systems requiring persistent time-stamping
• Telecommunications equipment needing precise timing references
• Embedded controllers requiring non-volatile memory and system reset management
• Industrial monitoring devices operating in extreme temperatures

Real Time Clock Procurement Notes

Verify the specific ordering suffix IND+ confirms the industrial temperature range (-40°C to +85°C) and lead-free status. Ensure the separate DS9034PCX PowerCap module is procured if surface-mount assembly is required, as the base chip does not contain the external crystal or battery components. Confirm voltage requirements match the 5V specification provided in the datasheet.

Real Time Clock Selection Notes

Select this component when a combined RTC and large NV SRAM solution is needed in a compact module form factor. The PowerCap package allows the battery and crystal to be mounted after reflow soldering, protecting sensitive components from heat. Compare against the 32-pin EDIP version if through-hole mounting is preferred or if the external PowerCap module is undesirable due to board space constraints.

Real Time Clock Part Context

This part belongs to the DS1554 family of nonvolatile timekeeping RAMs. The 'P' designation indicates the 34-pin PowerCap module package, while 'IND' specifies the industrial temperature rating. It is functionally similar to the DS1557 but offers different storage capacities and package options. The device replaces older discrete RTC and battery-backed SRAM designs by integrating all necessary timing and power management functions into a single IC.

Real Time Clock Replacement Considerations

Direct substitutes within the same package and electrical specifications are limited. The DS1554P-70+ serves as the commercial temperature variant. For pin-compatible replacements, verify that any alternative RTC/NVRAM combination matches the 34-pin PowerCap footprint and 5V operation. Cross-referencing with the DS1747 series may provide functional alternatives, though package differences must be addressed.