DS1244WP-120IND+

Overview

The DS1244WP-120IND+ is a nonvolatile SRAM integrated with a phantom real-time clock, manufactured by Analog Devices Inc./Maxim Integrated. It provides 32KB (32K x 8) of battery-backed memory and tracks time including hundredths of seconds, minutes, hours, days, dates, months, and years. The device operates on a parallel interface within a 34-pin PowerCap™ Module package designed for surface mount applications. It supports a supply voltage range of 2.97V to 3.63V and maintains data retention for over 10 years using an embedded lithium energy source. The industrial grade version functions reliably between -40°C and +85°C.

Feature Summary

• Integrates 32K x 8 NV SRAM with a phantom clock for timekeeping up to the year 2100.
• Features automatic leap year compensation and BCD-formatted registers.
• Utilizes a 34-pin PowerCap module package allowing separate mounting of the battery and crystal.
• Includes automatic write protection and power-fail switching to preserve data during voltage drops.

Applications

• Industrial control systems requiring persistent time and data logging.
• Embedded devices needing nonvolatile storage with calendar functionality.
• Equipment requiring high reliability in extreme temperature environments (-40°C to +85°C).

Procurement Notes

Verify that the required PowerCap component (DS9034PCX+ or DS9034I-PCX+) is ordered separately, as it contains the necessary lithium battery and crystal. Confirm the specific suffix IND indicates the industrial temperature range. Ensure the design accommodates the 34-pin PowerCap module footprint and allows for post-reflow assembly of the PowerCap unit to protect internal components from soldering heat.

Selection Notes

Select this model when a parallel interface and 32KB capacity are required alongside RTC capabilities. Compare against the DS1248WP series if larger memory density is needed, noting that the DS1248 offers 128KB. Ensure the system voltage aligns with the 3.3V operating range specified for the W-120 variant. Verify compatibility with the 34-pin PowerCap module form factor versus the 28-pin EDIP DIP module if through-hole mounting is preferred.

Part Context

This component belongs to the DS1244/DS1244P family of 256Kb NV SRAMs with phantom clocks. The 'W' suffix denotes the 3.3V logic version, while 'IND' specifies the industrial temperature rating. The 'P' indicates the PowerCap module package style. It is pin-for-pin compatible with other members of the SmartWatch/Phantom Clock family such as the DS1248P and DS1251P when using the same package type.

Replacement Considerations

Direct substitutes include the DS1248WP-120IND+ for higher capacity (128KB) and the DS1251WP-120+ for even greater density (512KB), provided the application can accommodate the increased memory size. For through-hole requirements, the DS1244Y-120IND+ serves as a 5V alternative in the EDIP package.