DS1244W-120+

Overview

The DS1244W-120+ is a 3.3V phantom clock RTC IC with 32KB NV SRAM in a 28-pin EDIP module. It integrates a lithium energy source for data retention and timekeeping during power loss, featuring automatic leap year compensation up to 2100. The device operates within a 2.97V to 3.63V supply range, drawing a maximum of 7mA at 3.3V. It supports parallel interfaces with standard JEDEC pinouts and provides time formats including HH:MM:SS:hh (12/24 hour) and date formats YY-MM-DD-dd. Designed for commercial temperatures from 0°C to +70°C, it ensures over 10 years of data retention without primary power.

Feature Summary

• Integrated 32K x 8 NV SRAM with phantom clock functionality
• Automatic leap year compensation valid through 2100
• Embedded lithium battery maintains operation during VCC failure
• Standard 28-pin JEDEC compatible EDIP package

Applications

• Systems requiring non-volatile timekeeping and data storage
• Industrial control units needing calendar functions
• Equipment requiring data integrity during power outages

Procurement Notes

Verify the specific suffix 'W' indicates the commercial temperature grade (0°C to +70°C) and 3.3V operation. Confirm the EDIP package type matches the target PCB footprint. Check RoHS compliance status as indicated by the '+' suffix. Ensure the design accounts for the separate ordering of PowerCap modules if surface mount variants are considered instead.

Selection Notes

Select this component when a parallel interface is required alongside persistent timekeeping. Compare against the DS1244Y-70+ for 5V applications or the DS1244WP-120+ for surface mount PowerCap configurations. Verify that the 120ns access time meets system timing constraints. Consider the industrial grade DS1244W-120IND+ if operation below 0°C is necessary.

Part Context

This part belongs to the DS1244 family of phantom clock RTCs manufactured by Analog Devices Inc./Maxim Integrated. It serves as a direct replacement for volatile static RAM or EEPROM in systems requiring backup capabilities. The device distinguishes itself by combining memory and real-time clock functions into a single encapsulated DIP module, simplifying board layout compared to discrete solutions.

Replacement Considerations

The DS1244W-120IND+ offers identical electrical characteristics but extends the operating temperature range to -40°C to +85°C. For surface mount requirements, the DS1244WP-120+ provides pin-for-pin compatibility with PowerCap modules.