DS1244Y-70+

Overview

The DS1244Y-70+ is a 256K nonvolatile SRAM with an integrated phantom real-time clock, manufactured by Analog Devices Inc./Maxim Integrated. It features 32KB of NV SRAM organized as 32K x 8 bits and operates on a single 5V supply within the 4.5V to 5.5V range. The device provides a 70ns access time and draws up to 10mA during timekeeping. Packaged in a 28-pin EDIP module for through-hole mounting, it includes an embedded lithium energy source that maintains calendar operation and data retention for over 10 years when VCC is absent.

Feature Summary

• Integrates 32K x 8 NV SRAM with automatic leap year compensation valid up to 2100
• Phantom clock interface allows transparent timekeeping via serial bit stream pattern recognition
• Embedded lithium battery ensures data retention for over 10 years without external power
• Supports 12-hour (with AM/PM) or 24-hour time formats and YY-MM-DD-dd date format

Applications

• Systems requiring persistent timekeeping and volatile RAM replacement
• Industrial equipment needing reliable calendar and clock functions
• Data logging devices requiring nonvolatile storage with timestamping

Procurement Notes

Verify the specific suffix Y-70+ corresponds to the 5.0V operating voltage and commercial temperature range (0°C to +70°C). Confirm the package type is the 28-pin EDIP module rather than the PowerCap variant. Ensure the order includes only the IC if using the DIP module, as the PowerCap version requires a separate battery component.

Selection Notes

Select this part for applications requiring parallel interface compatibility with standard SRAM pinouts while adding RTC capabilities. The phantom clock mechanism requires specific software initialization sequences involving 64-bit pattern recognition. Compare against the DS1244W series if a 3.3V supply is required, noting differences in access times and current consumption.

Part Context

This component belongs to the DS1244 family of 256K NV SRAMs with phantom clocks. It is functionally similar to the DS1248P and DS1251P but utilizes a distinct phantom clock protocol. The Y-70+ designation specifies the 70ns speed grade and 5V voltage rating within the commercial temperature range.

Replacement Considerations

Pin-for-pin compatible with DS1248P and DS1251P modules. Verify software compatibility regarding the phantom clock register access sequence, as these differ from SmartWatch-based RTCs.