DS1746P-70IND

Real Time Clock Overview

The DS1746P-70IND is a Y2K-compliant, nonvolatile timekeeping RAM integrating a real-time clock/calendar and 128k x 8 static RAM. It operates on a 5V supply within an industrial temperature range of -40°C to +85°C. The device utilizes a parallel interface with standard JEDEC byte-wide pinouts. Key features include automatic leap year compensation valid until 2100, double-buffered clock registers, and power-fail write protection. It employs a 34-pin PowerCap module package designed for surface-mount assembly, connecting externally to a separate PowerCap containing the lithium energy source and crystal.

Real Time Clock Feature Summary

• Integrates RTC, 128KB NV SRAM, crystal, and power-fail control circuit in a single component architecture.
• Features BCD-coded time/date registers with automatic leap year compensation valid through the year 2100.
• Includes power-fail write protection that blocks access when VCC falls below the threshold, ensuring data integrity.
• Utilizes a 34-pin PowerCap module board package requiring a separate DS9034PCX+ or DS9034I-PCX+ PowerCap for battery and crystal connection.

Real Time Clock Applications

• Industrial systems requiring robust timekeeping and nonvolatile data storage under extreme temperatures.
• Embedded controllers needing direct parallel RAM interface with integrated calendar functions.
• Equipment requiring Y2K compliance and long-term battery-backed data retention without field calibration.

Real Time Clock Procurement Notes

Verify the specific ordering suffix against the manufacturer's current catalog, as legacy Maxim Integrated products may have transitioned statuses or packaging variations under Analog Devices. Confirm the necessity of the separate PowerCap module (DS9034 series) for system design, as the DS1746P-70IND does not contain the internal battery or crystal required for standalone operation.

Real Time Clock Selection Notes

Select this part for applications requiring a 5V logic interface and industrial temperature stability (-40°C to +85°C). Ensure the design accommodates the 34-pin PowerCap footprint and the external mounting of the PowerCap after surface reflow to protect the lithium source. Compare against the DS1746-70IND if a through-hole DIP package with integrated components is preferred over the surface-mountable PowerCap solution.

Real Time Clock Part Context

The DS1746P-70IND belongs to the DS1746/DS1746P family of Y2K-compliant nonvolatile timekeeping RAMs. It is functionally compatible with other densities in the DS174x series, allowing for density upgrades while maintaining pin compatibility. The 'P' designation specifically indicates the PowerCap module package variant, distinguishing it from the encapsulated DIP modules like the DS1746-70IND.

Real Time Clock Replacement Considerations

The DS1746-70IND+ serves as a direct functional substitute offering identical electrical specifications but housed in a 32-pin EDIP package with integrated crystal and battery. Designers must account for the package difference and the absence of the external PowerCap requirement when switching to the DIP variant.