DS1244W-120IND

Overview

The DS1244W-120IND is a 256K nonvolatile SRAM integrated with a phantom real-time clock, manufactured by Analog Devices Inc./Maxim Integrated. It operates within a supply voltage range of 2.97V to 3.63V and draws a maximum timekeeping current of 7mA at 3.3V. The device features 32KB (32K x 8) NVSRAM and supports parallel interface communication. It provides automatic leap year compensation valid up to the year 2100 and maintains data retention for over 10 years in the absence of power. The component is housed in a 28-pin EDIP module package designed for through-hole mounting and functions reliably across an industrial temperature range of -40°C to +85°C.

Feature Summary

• Integrates 32K x 8 NVSRAM with a phantom clock for timekeeping and calendar functions.
• Includes embedded lithium energy cell that automatically switches on during power failure.
• Provides automatic leap year compensation valid up to the year 2100.
• Ensures over 10 years of data retention when VCC is absent.

Applications

• Industrial systems requiring persistent timekeeping and data storage.
• Embedded controllers needing volatile RAM replacement with nonvolatile capabilities.
• Equipment requiring battery-backed memory protection against power loss.

Procurement Notes

Verify the specific suffix IND confirms the -40°C to +85°C industrial temperature grade. Confirm the EDIP package type matches the required through-hole footprint. Check for lead-free/RoHS compliance status indicated by the '+' suffix if applicable. Ensure the 3.3V operating voltage aligns with the system design requirements.

Selection Notes

Select this part for applications requiring direct parallel interface compatibility with standard SRAM pinouts while adding RTC functionality. The 28-pin EDIP package is suitable for through-hole assembly processes. Consider the 120ns access time for timing constraints. Verify that the system can support the 64-bit pattern recognition sequence required to access the phantom clock registers.

Part Context

This component belongs to the DS1244 family of 256K NV SRAMs with phantom clocks. It is functionally similar to the DS1244Y series but operates at a lower 3.3V supply voltage compared to the 5V DS1244Y variants. The 'W' indicates the commercial/industrial temperature range variant in the EDIP package, distinct from the PowerCap surface-mount version.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. The DS1244Y-70 is a related 5V variant but requires voltage level adjustment. No direct cross-model substitutes are listed.