AT27C512R-90JC Equivalent & Substitute Parts

Part Overview

The AT27C512R-90JC is a 512Kbit EPROM (Erasable Programmable Read-Only Memory) manufactured by Microchip Technology in a 32-PLCC surface mount package with 90 ns access time. This part is classified as obsolete, making substitute components necessary for new designs and ongoing production support. The AT27C512R-90JC operates within a 4.5V to 5.5V supply voltage range and supports parallel memory interface architecture typical of legacy embedded systems and industrial applications.

Substiute Parts

AT27C512R-90JC

Microchip TechnologyIn Stock: 1766AT27C512R-90JC Datasheet

Current PartRFQ

AT27LV512A-90JU

Microchip TechnologyIn Stock: 1509AT27LV512A-90JU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT27C512R-90JC is determined by strict equivalence across the following critical parameters:

Memory capacity and organization must remain 512Kbit in 64K x 8 configuration to maintain firmware compatibility and address space requirements. The parallel memory interface is mandatory for direct pin-level compatibility with existing circuit designs. Access time of 90 ns establishes the maximum allowable propagation delay; substitute parts meeting or exceeding this specification are electrically compatible. The 32-PLCC package with identical physical dimensions (13.97x11.43) ensures mechanical fit on existing PCBs without layout modifications.

The AT27LV512A-90JU qualifies as a direct substitute based on these parameters: it maintains 512Kbit capacity in 64K x 8 organization, preserves the parallel interface, matches the 90 ns access time specification, and uses the identical 32-PLCC package footprint.

Parameter Comparison

Engineering Selection Recommendations

The AT27LV512A-90JU is the qualified substitute for the AT27C512R-90JC. The substitute part maintains active product status with Microchip Technology, ensuring continued availability and manufacturing support. The AT27LV512A-90JU achieves ROHS3 compliance, addressing regulatory requirements for new production and environmental standards. The extended operating temperature range (-40°C to 85°C) and dual voltage support (3V to 3.6V and 4.5V to 5.5V) provide operational flexibility beyond the original part specification while maintaining full backward compatibility for 5V applications.

Frequently Asked Questions (FAQ)

Q: Can the AT27LV512A-90JU directly replace the AT27C512R-90JC without PCB modifications?

A: Yes. Both parts use the identical 32-PLCC package with matching physical dimensions (13.97x11.43 mm). Pin assignments and electrical interface remain compatible for 5V supply applications.

Q: What is the significance of the extended temperature range in the AT27LV512A-90JU?

A: The AT27LV512A-90JU operates from -40°C to 85°C compared to the original 0°C to 70°C range. This extended specification accommodates industrial and automotive environments with wider thermal requirements while maintaining full compatibility in standard 0°C to 70°C applications.

Q: Does the dual voltage capability of the AT27LV512A-90JU affect compatibility?

A: No. The AT27LV512A-90JU supports both 3V to 3.6V and 4.5V to 5.5V supply ranges. Existing designs operating at 4.5V to 5.5V function identically to the original part. The additional 3V range provides design flexibility for new applications.

Q: Why is RoHS compliance important for this substitution?

A: The AT27LV512A-90JU achieves ROHS3 compliance, meeting current environmental and regulatory standards for component manufacturing and distribution. The original AT27C512R-90JC is RoHS non-compliant, making the substitute necessary for applications subject to RoHS requirements.

Q: Are there any access time or performance differences between these parts?

A: No. Both parts specify 90 ns access time, ensuring identical timing performance in parallel memory interface applications.