AT49F040-12JC Equivalent & Substitute Parts

Part Overview

The AT49F040-12JC is a 4Mbit parallel FLASH memory IC manufactured by Microchip Technology in a 32-PLCC package with 120 ns access time. This component is classified as obsolete, making equivalent substitute parts necessary for ongoing system support, maintenance, and new design implementations where legacy compatibility is required.

Substiute Parts

AT49F040-12JC

Microchip TechnologyIn Stock: 2277AT49F040-12JC Datasheet

Current PartRFQ

AS29CF040-55CCIN

Alliance Memory, Inc.In Stock: 2525AS29CF040-55CCIN Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT49F040-12JC is determined by the following critical parameters that must remain constant or compatible:

• Memory capacity: 4Mbit (512K x 8 organization)
• Interface type: Parallel
• Package: 32-PLCC with identical physical dimensions (13.97x11.43)
• Supply voltage: 4.5V ~ 5.5V compatibility
• Memory technology: FLASH (NOR-type acceptable)

The AS29CF040-55CCIN from Alliance Memory qualifies as a direct substitute based on matching memory size, organization, interface, and package specifications. Performance characteristics (access time and write cycle time) are improved in the substitute part, ensuring backward compatibility with existing designs.

Parameter Comparison

Engineering Selection Recommendations

The AS29CF040-55CCIN is the qualified substitute for AT49F040-12JC applications. Selection is based on the following factors:

• Functional equivalence: Identical memory capacity, organization, and parallel interface
• Package compatibility: Identical 32-PLCC footprint and pin configuration
• Electrical compatibility: Matching supply voltage range (4.5V ~ 5.5V)
• Performance improvement: Faster access time (55 ns vs. 120 ns) and write cycle time ensure no timing violations in existing designs
• Product availability: Active status with current inventory
• Compliance: ROHS3 compliant substitute addresses regulatory requirements where applicable

The substitute part operates across an extended temperature range (-40°C ~ 85°C) compared to the original (0°C ~ 70°C), providing additional operational margin for demanding environments.

Frequently Asked Questions (FAQ)

Q: Can AS29CF040-55CCIN directly replace AT49F040-12JC in existing designs?

A: Yes. Both parts share identical memory capacity (4Mbit), organization (512K x 8), parallel interface, and 32-PLCC package dimensions. Electrical specifications (supply voltage 4.5V ~ 5.5V) are compatible. The substitute offers improved performance with faster access and write times.

Q: What are the key differences between these parts?

A: The primary differences are manufacturer (Microchip vs. Alliance Memory), product status (obsolete vs. active), access time (120 ns vs. 55 ns), operating temperature range (0°C ~ 70°C vs. -40°C ~ 85°C), and RoHS compliance status (non-compliant vs. ROHS3 compliant).

Q: Are there any package or pinout considerations?

A: Both parts use identical 32-PLCC packages with matching physical dimensions (13.97x11.43 mm). No PCB layout modifications are required for substitution.

Q: Does the faster access time of the substitute part affect compatibility?

A: No. Faster access time (55 ns vs. 120 ns) is backward compatible and will not cause timing violations in designs specified for the original 120 ns part.

Q: What is the temperature operating range difference?

A: The substitute operates from -40°C to 85°C compared to the original 0°C to 70°C. This extended range provides additional operational margin and is suitable for wider environmental conditions.