AT28C256E-25UM/883-815

Memory IC Overview

The AT28C256E-25UM/883-815 is a military-grade, 256-Kbit (32,768 x 8) paged parallel EEPROM manufactured by Microchip Technology. It features a 250 ns access time and operates on a single 5V ± 10% supply. The device supports page write operations of up to 64 bytes with a maximum cycle time of 10 ms. It includes hardware and software data protection mechanisms, DATA Polling for end-of-write detection, and an extra 64 bytes for device identification. The component utilizes high-reliability CMOS technology and is available in a 28-pin PGA package.

Memory IC Feature Summary

• Supports automatic page write operations for efficient data programming
• Includes hardware and software data protection against inadvertent writes
• Features DATA Polling and Toggle Bit capabilities for write cycle monitoring
• Provides additional non-volatile memory space for device identification

Memory IC Applications

• Military aerospace systems requiring radiation-hardened or high-reliability memory
• Avionics control units needing secure data storage
• Defense communication equipment requiring robust non-volatile storage
• Industrial automation controllers operating in extreme environments

Memory IC Procurement Notes

Verify the specific suffix codes to confirm the exact access time, endurance rating, and Software Data Protection (SDP) status. Ensure the ordering information matches the required MIL-STD-38535 screening level. Confirm that the 28-pin PGA package dimensions align with the target PCB footprint. Check for any export control restrictions associated with military-grade components.

Memory IC Selection Notes

Select this component when a 250 ns access speed is sufficient for the system timing requirements. Consider the 10 ms standard write cycle time versus the faster 3 ms option if write performance is critical. Verify compatibility with the host system's voltage levels and interface signals. Evaluate the need for the specific 28-pin PGA form factor against other available packages like CLCC or CERDIP.

Memory IC Part Context

This part belongs to the AT28C256 family of 256-Kbit parallel EEPROMs designed for high-reliability applications. It shares architectural similarities with other variants but differs in package type and electrical specifications. The 'UM' designation indicates the 28-pin PGA package, while '/883' denotes compliance with MIL-STD-38535 standards. It serves as a drop-in replacement for legacy Atmel/Microchip EEPROMs in military designs.

Memory IC Replacement Considerations

Direct substitutes include other AT28C256 variants with different access times or packages, such as AT28C256-15UM/883 or AT28C256-20UM/883. Cross-family replacements may require logic level adjustments. Verify pinout compatibility before substituting with similar capacity EEPROMs from other manufacturers.