AT29C020-90JU-T Equivalent & Substitute Parts

Part Overview

The AT29C020-90JU-T is a 2Mbit parallel FLASH memory IC manufactured by Microchip Technology, housed in a 32-PLCC package with 90 ns access time. This device is classified as obsolete, making substitute parts necessary for new designs and production continuity. The part operates within a 4.5V to 5.5V supply voltage range and supports standard parallel memory interface protocols.

Substiute Parts

AT29C020-90JU-T

Microchip TechnologyIn Stock: 996AT29C020-90JU-T Datasheet

Current PartRFQ

SST39VF020-70-4I-NHE

Microchip TechnologyIn Stock: 1966SST39VF020-70-4I-NHE Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the AT29C020-90JU-T is determined by the following critical parameters:

• Memory capacity (2Mbit) and organization (256K x 8)
• Parallel memory interface compatibility
• 32-PLCC package footprint and pinout alignment
• Surface mount mounting type
• Operating temperature range (-40°C ~ 85°C)
• RoHS3 compliance certification

The SST39VF020-70-4I-NHE meets these core substitution criteria. However, differences exist in access time (70 ns vs. 90 ns), supply voltage range (2.7V ~ 3.6V vs. 4.5V ~ 5.5V), write cycle time (20µs vs. 10ms), and moisture sensitivity level. These differences must be evaluated against specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

The SST39VF020-70-4I-NHE is the qualified substitute for the AT29C020-90JU-T based on matching memory capacity, organization, parallel interface, package type, and RoHS3 compliance. The substitute part is currently in active production status, ensuring long-term availability.

Key considerations for selection:

• The substitute operates at a lower supply voltage range (2.7V ~ 3.6V), requiring verification that system power supplies can accommodate this specification.
• The substitute provides faster access time (70 ns), which is compatible with applications designed for 90 ns operation.
• The substitute features significantly faster write cycle time (20µs vs. 10ms), which may affect firmware timing assumptions in legacy designs.
• Both parts maintain identical operating temperature range and RoHS3 compliance.

Frequently Asked Questions (FAQ)

Q: Can the SST39VF020-70-4I-NHE directly replace the AT29C020-90JU-T in existing designs?

A: Physical and functional compatibility exists due to matching memory capacity, organization, parallel interface, and 32-PLCC package. However, the different supply voltage range (2.7V ~ 3.6V vs. 4.5V ~ 5.5V) requires system-level verification. The faster access time and write cycle time of the substitute are backward-compatible with designs specified for the original part.

Q: What is the significance of the different write cycle times?

A: The AT29C020-90JU-T specifies 10ms write cycle time, while the SST39VF020-70-4I-NHE specifies 20µs. If firmware or system timing relies on the 10ms specification, the faster write cycle of the substitute will not cause functional issues. Timing-critical applications should verify that the faster write cycle does not introduce unexpected behavior.

Q: Are both parts RoHS3 compliant?

A: Yes, both the AT29C020-90JU-T and SST39VF020-70-4I-NHE are ROHS3 compliant, meeting environmental and regulatory requirements for equivalent applications.

Q: What packaging differences exist between these parts?

A: Both parts use 32-PLCC (J-Lead) packages with identical pinout and footprint. The AT29C020-90JU-T is supplied in Tape & Reel format, while the SST39VF020-70-4I-NHE is supplied in Tube format. This affects procurement and handling but does not impact electrical or mechanical compatibility.

Q: Why is the original part classified as obsolete?

A: The AT29C020-90JU-T is no longer in active production. The SST39VF020-70-4I-NHE, also from Microchip Technology's SST39 MPF series, represents the active equivalent for new designs and production continuity.