AT49F001T-55JC Equivalent & Substitute Parts

Part Overview

The AT49F001T-55JC is a 1Mbit parallel FLASH memory IC manufactured by Microchip Technology, housed in a 32-PLCC package with 55 ns access time. This device is classified as obsolete and is no longer in active production. Finding equivalent substitute parts is necessary due to the discontinued status of this component, which impacts long-term availability for maintenance, repair, and legacy system support.

Substiute Parts

AT49F001T-55JC

Microchip TechnologyIn Stock: 1155AT49F001T-55JC Datasheet

Current PartRFQ

SST39VF010-70-4C-NHE

Microchip TechnologyIn Stock: 3949SST39VF010-70-4C-NHE Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT49F001T-55JC is determined by the following critical parameters:

Core Compatibility Requirements:

• Memory capacity: 1Mbit (128K x 8 organization)
• Interface type: Parallel
• Package type: 32-PLCC (J-Lead)
• Mounting: Surface Mount

Performance Considerations:

• Access time tolerance: The substitute part may have equal or slower access time (55 ns or greater)
• Supply voltage: The substitute must operate within or be compatible with the system's voltage requirements
• Operating temperature range: Must support 0°C to 70°C minimum

The SST39VF010-70-4C-NHE meets all core compatibility requirements with identical memory capacity, organization, interface, and package specifications. The substitute operates at 70 ns access time, which is acceptable for systems designed for the original 55 ns specification. Supply voltage differs (2.7V ~ 3.6V vs. 4.5V ~ 5.5V), requiring voltage compatibility verification in the target application.

Parameter Comparison

Engineering Selection Recommendations

SST39VF010-70-4C-NHE as Primary Substitute:

The SST39VF010-70-4C-NHE is the designated manufacturer-recommended substitute. Selection is based on:

• Active Product Status: The substitute is in active production, ensuring long-term availability and supply chain stability compared to the obsolete AT49F001T-55JC.
• Regulatory Compliance: ROHS3 compliance of the substitute meets current environmental and regulatory standards, whereas the original part is non-compliant.
• Functional Equivalence: Identical memory capacity, organization, interface type, and package specifications ensure direct functional replacement.
• Performance Trade-offs: The 70 ns access time is 15 ns slower than the original 55 ns specification. This is acceptable for systems with timing margins that accommodate the slower access time. The improved write cycle time (20µs vs. 50µs) provides faster programming performance.
• Voltage Consideration: The substitute operates at 2.7V ~ 3.6V, which differs from the original 4.5V ~ 5.5V specification. System voltage compatibility must be confirmed before implementation.

Frequently Asked Questions (FAQ)

Q: Can the SST39VF010-70-4C-NHE directly replace the AT49F001T-55JC without circuit modifications?

A: Direct pin-compatible replacement is possible due to identical package and pinout. However, the different supply voltage range (2.7V ~ 3.6V vs. 4.5V ~ 5.5V) requires verification that the system power supply and signal levels are compatible with the substitute part's specifications.

Q: What is the impact of the 15 ns slower access time (70 ns vs. 55 ns)?

A: The slower access time affects data retrieval speed. Systems designed with timing margins can accommodate this difference. Applications with strict timing requirements must evaluate whether the 70 ns access time meets performance specifications.

Q: Why is the substitute part's write cycle time faster (20µs vs. 50µs)?

A: The SST39VF010-70-4C-NHE uses improved FLASH technology that enables faster programming cycles. This is a performance advantage and does not affect substitution compatibility.

Q: Is the 32-PLCC package identical between both parts?

A: Both parts use 32-LCC (J-Lead) packaging. Physical dimensions are 13.97x11.43 mm for the original and 11.43x13.97 mm for the substitute (rotated orientation). PCB footprint compatibility must be confirmed.

Q: What does the active product status of the substitute mean for procurement?

A: Active status indicates the SST39VF010-70-4C-NHE is in current production with established supply chains. This ensures availability for new orders and long-term support, unlike the obsolete AT49F001T-55JC.

Q: Are there RoHS compliance implications for using the substitute?

A: The substitute is ROHS3 compliant, meeting current environmental regulations. The original part is non-compliant. Use of the substitute aligns with modern regulatory requirements for new designs and manufacturing.