DS1251WP-120

Overview

The DS1251WP-120+ is a nonvolatile SRAM integrated with a phantom clock real-time controller, manufactured by Analog Devices Inc./Maxim Integrated. It provides 512K x 8 bits of static RAM and maintains timekeeping data via an embedded lithium energy cell. The device features a parallel interface with 19 address lines and 8 data lines, operating within a supply voltage range of 2.97V to 3.63V. It supports automatic leap year compensation up to the year 2100 and ensures over 10 years of data retention without power. The component is housed in a 34-pin PowerCap Module package designed for surface mount applications.

Feature Summary

• Integrates 512K x 8 NV SRAM with a phantom clock for calendar and timekeeping functions
• Includes automatic leap year compensation valid through the year 2100
• Features a replaceable PowerCap module containing the battery and crystal
• Maintains data retention for over 10 years using an internal lithium energy source

Applications

• Systems requiring persistent timekeeping during main power loss
• Data logging applications needing nonvolatile storage
• Industrial equipment requiring calendar tracking

Procurement Notes

Verify that the separate DS9034PCX+ or DS9034I-PCX+ PowerCap module is ordered, as it is required for operation but not included with the chip. Confirm the specific suffix (IND+) matches the required temperature range of -40°C to +85°C if industrial grade is needed. Ensure the design accommodates the 34-pin PowerCap Module footprint.

Selection Notes

Select this part when a direct replacement for volatile SRAM or EEPROM is needed alongside RTC functionality. The 120ns access speed suits standard parallel bus architectures. Verify compatibility with the 3.3V logic levels and ensure the system can handle the pattern recognition sequence required to access the phantom clock registers.

Part Context

This component belongs to the DS1251 series of Phantom Clock modules. It is upward compatible with the DS1248 series and shares pinouts with other densities in the DS124xP family. The 'WP' designation indicates the PowerCap board-only package, distinguishing it from the DIP modules that integrate the battery internally.

Replacement Considerations

DS1251WP-120IND+