AT28C256E-15UM/883

Memory IC Overview

The AT28C256E-15UM/883 is a military-grade, 256-Kbit (32,768 x 8) paged parallel EEPROM manufactured by Microchip Technology. It features a fast read access time of 150 ns and supports page write operations for up to 64 bytes simultaneously. The device operates on a single 5V ± 10% supply with low-power CMOS standby current. It includes hardware and software data protection mechanisms, DATA Polling for end-of-write detection, and an extra 64 bytes of EEPROM for device identification.

Memory IC Feature Summary

• Supports automatic page write operations allowing simultaneous writing of up to 64 bytes using internal address and data latches.
• Includes hardware and software data protection features to prevent inadvertent writes during power transitions or system noise.
• Provides DATA Polling and Toggle Bit functionality to efficiently detect the completion of internal write cycles.

Memory IC Applications

• Military aerospace systems requiring high-reliability nonvolatile memory
• Industrial control applications needing robust data retention
• Embedded tracking and device identification modules

Memory IC Procurement Notes

Verify that the ordering suffix /883 confirms compliance with MIL-STD-1835 specifications. Confirm the 'E' suffix indicates extended endurance ratings as documented in the datasheet. Ensure export documentation requirements are met due to potential restrictions on military-grade components originating from the United States.

Memory IC Selection Notes

Select this component when a 150 ns access time and 28-pin PGA package are required for through-hole mounting. Verify compatibility with 5V logic levels and ensure the application can support the specific Software Data Protection algorithm if write security is critical. Consider the 10-year data retention and high cycle endurance for long-life deployments.

Memory IC Part Context

This part belongs to the AT28C256 family of 256-Kbit parallel EEPROMs designed for harsh environments. It utilizes advanced nonvolatile CMOS technology to provide static RAM-like access speeds. The device is JEDEC approved for byte-wide pinout compatibility, ensuring integration into existing designs without significant layout modifications.

Memory IC Replacement Considerations

Compatible substitutes include other AT28C256 variants with different access times or packages, such as the AT28C256-20UM/883 or AT28C256-25UM/883, provided timing constraints allow for slower performance. Cross-reference with 5962-88525 equivalents for direct military specification matching.

Memory IC FAQ

How does the Software Data Protection (SDP) feature function?

SDP prevents inadvertent writes by requiring a specific three-byte command sequence to be written to designated addresses before any programming operation can occur. This state persists through power transitions until explicitly disabled via a separate command sequence.

What is the purpose of the extra 64 bytes of EEPROM memory?

The additional 64 bytes are reserved for device identification or tracking purposes. They are accessed by raising address A9 to 12V and using address locations 7FC0H to 7FFFH.