27HC256L-90/J

Overview

The 27HC256L-90/J is a 256K-bit (32K x 8) CMOS UV Erasable Programmable Read-Only Memory manufactured by Microchip Technology. It features a 90 ns access time and operates within a standard 5V supply voltage range. The device is housed in a 28-pin Ceramic Dual In-Line Package (CDIP-28) with a 0.600-inch body width. Designed for industrial applications, it supports asynchronous operation and includes three-state outputs for bus compatibility.

Feature Summary

• UV erasable non-volatile memory architecture
• Industrial temperature grade ruggedization
• Three-state output buffering

Applications

• Industrial control systems
• Embedded firmware storage
• Ruggedized electronic equipment

Procurement Notes

Verify the specific suffix 'J' corresponds to the ceramic DIP package and industrial rating. Confirm RoHS compliance status as sources indicate lead-free variations may exist. Ensure the UV window on the package is intact for potential field erasure if required by the design. Check export restrictions if applicable.

Selection Notes

Select this component when a high-reliability, radiation-hardened or ruggedized EPROM is required for industrial environments. The CDIP-28 package offers superior mechanical stability compared to plastic variants. Consider the 90 ns speed sufficient for most microcontroller address buses. Verify that the system design accommodates UV erasure requirements.

Part Context

This part belongs to the 27HC series of UV EPROMs from Microchip, designed for durability. It is functionally similar to other 256K-bit EPROMs but distinguished by its ceramic packaging and industrial temperature specifications. It serves as a legacy storage solution where data retention and ruggedness are prioritized over density.

Replacement Considerations

Direct replacements include the 27HC256L-55/J for faster access times or the AT28HC256 series for electrically erasable functionality. Ensure pinout compatibility with the 28-pin CDIP footprint. Verify voltage levels match the 5V requirement.