DS1251WP-120IND

Overview

The DS1251WP-120IND+ is a nonvolatile SRAM integrated with a phantom clock, packaged in a 34-pin PowerCap Module. It provides 512K x 8 bits of memory and maintains timekeeping data via an embedded lithium cell when VCC is absent. The device operates within a voltage range of 2.97V to 3.63V and supports an industrial temperature range of -40°C to +85°C. It utilizes a parallel interface with 19 address lines and 8 data lines. The maximum current consumption during timekeeping is 7mA at 3.3V.

Feature Summary

• Integrates 512K x 8 NV SRAM with a phantom clock for calendar and timekeeping functions.
• Features automatic leap year compensation valid up to the year 2100.
• Includes an embedded lithium energy source that disconnects electrically until initial power application.
• Supports 12-hour or 24-hour time formats with AM/PM indicators.

Applications

• Systems requiring persistent timekeeping and data storage without external battery management.
• Industrial equipment operating in extended temperature environments (-40°C to +85°C).
• Applications needing direct replacement for volatile static RAM or EEPROM with nonvolatile capabilities.

Procurement Notes

Verify the specific ordering suffix IND+ confirms the -40°C to +85°C industrial temperature rating and 3.3V operation. Confirm that the separate DS9034PCX+ or DS9034I-PCX+ PowerCap module is included, as it is required for board connection and contains the crystal and battery. Ensure compatibility with the 34-pin PowerCap footprint on the target PCB.

Selection Notes

Select this component over standard SRAM when nonvolatility and real-time clock functionality are required in a single package. The PowerCap variant allows surface-mount assembly before attaching the battery module, protecting sensitive components from reflow heat. Compare access times (120ns) and standby currents against system requirements. Ensure the host microcontroller supports the 64-bit pattern recognition sequence for phantom clock access.

Part Context

This part belongs to the DS1251 family of 4096K NV SRAMs with phantom clocks. It is upward compatible with the DS1248 series. The 'P' suffix denotes the PowerCap module board package, distinct from the EDIP DIP modules. The 'IND' suffix specifies the industrial temperature grade, while '+' indicates RoHS compliance.

Replacement Considerations

The datasheet notes upward compatibility with the DS1248 series. Verify pinout alignment and memory density differences if substituting. Ensure the replacement supports the same phantom clock protocol and voltage levels.