DS1244Y-70

Overview

The DS1244Y-70+ is a 256K nonvolatile SRAM integrated with a phantom real-time clock, packaged in a 28-pin EDIP module. It provides 32K x 8 bits of battery-backed memory and tracks time including hundredths of seconds, minutes, hours, days, dates, months, and years. The device operates on a single 5V supply (4.5V to 5.5V) with a maximum timekeeping current of 10mA at 5V. It features automatic leap year compensation valid through 2100 and ensures over 10 years of data retention via an embedded lithium energy source that activates upon power failure.

Feature Summary

• Integrates 32K x 8 NV SRAM with a phantom clock for simultaneous timekeeping and data storage
• Includes an embedded lithium energy cell that automatically switches on during power failures
• Provides automatic leap year compensation valid up to the year 2100
• Supports 12-hour or 24-hour time formats with AM/PM indicators

Applications

• Systems requiring persistent timekeeping without external crystals or batteries
• Data logging applications needing nonvolatile memory backup
• Industrial control systems operating within commercial temperature ranges

Procurement Notes

Verify the specific suffix 'Y-70+' indicates the 5V version in the 28-pin EDIP package. Confirm RoHS compliance status based on the '+' designation. Ensure the application circuit respects the absolute maximum ratings, particularly regarding negative undershoots during battery-backup mode which are strictly prohibited.

Selection Notes

Select this component when a parallel interface is required for both memory and RTC functions. The 28-pin DIP module form factor simplifies PCB layout by integrating the crystal and battery. Compare against the DS1244P variant if surface-mount assembly with a separate PowerCap battery module is preferred for reflow soldering compatibility.

Part Context

This part belongs to the DS1244 family of 256K NV SRAMs with phantom clocks. It is functionally similar to the DS1248 but offers higher density. The 'Y' suffix denotes the 5V voltage variant, while 'W' variants support 3.3V operation. The device replaces volatile static RAM or EEPROM in designs requiring continuous time tracking.

Replacement Considerations

Pin-for-pin compatible replacements include other DS1244 series variants with matching voltage and speed grades. For surface-mount requirements, the DS1244P can be used with a DS9034PCX+ PowerCap module.