AT25DF021-SSH-T Equivalent & Substitute Parts

Part Overview

The AT25DF021-SSH-T is a 2Mbit Serial Peripheral Interface (SPI) FLASH memory IC manufactured by Microchip Technology, housed in an 8-SOIC package. This device operates at 70 MHz and is designed for non-volatile data storage applications requiring SPI interface connectivity. The part is currently classified as obsolete, making equivalent and substitute parts necessary for ongoing system support and new design implementations. Substitute parts must maintain compatibility across memory capacity, interface protocol, package form factor, and voltage supply specifications.

Substiute Parts

AT25DF021-SSH-T

Microchip TechnologyIn Stock: 17148AT25DF021-SSH-T Datasheet

Current PartRFQ

SST25VF020B-80-4I-SAE

Microchip TechnologyIn Stock: 10389SST25VF020B-80-4I-SAE Datasheet

MFR RecommendedRFQ

LE25U20AMB-AH

onsemiIn Stock: 10365LE25U20AMB-AH Datasheet

MFR RecommendedRFQ

W25X20CLSNIG

Winbond ElectronicsIn Stock: 55503W25X20CLSNIG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the AT25DF021-SSH-T is determined by the following mandatory parameters:

• Memory Capacity: 2Mbit (256K x 8 organization)
• Interface Protocol: SPI
• Package Type: 8-SOIC with 0.154" (3.90mm) width
• Voltage Supply Compatibility: Minimum 2.7V support required
• Operating Temperature Range: -40°C to 85°C minimum
• Surface Mount Technology: Required for PCB integration compatibility

All three substitute parts meet these core requirements. Variations in clock frequency (70 MHz to 104 MHz), write cycle times, and product status (active vs. obsolete) do not disqualify substitution but represent performance and availability differences that must be evaluated for specific application requirements.

Parameter Comparison

Engineering Selection Recommendations

SST25VF020B-80-4I-SAE (Microchip Technology): This substitute maintains the same manufacturer lineage as the original AT25DF021-SSH-T. It operates at 80 MHz, providing marginal performance improvement over the original 70 MHz specification. The part is active in production with verified programmability status and MSL Level 1 rating, indicating superior moisture handling characteristics. Voltage supply range and operating temperature specifications are identical to the original part.

W25X20CLSNIG (Winbond Electronics): This substitute offers the highest clock frequency at 104 MHz among all options, supporting applications requiring enhanced data throughput. The part is active in production with verified programmability status. Extended voltage supply compatibility (2.3V minimum) provides broader operational flexibility. MSL Level 3 rating requires controlled storage conditions (168-hour limit after moisture exposure).

LE25U20AMB-AH (onsemi): This substitute operates at 30 MHz, representing reduced performance relative to the original 70 MHz specification. The part is active in production but carries unverified programmability status. Extended voltage supply compatibility (2.3V minimum) is provided. MSL Level 3 rating applies. This option is suitable for applications where clock frequency is not performance-critical and cost optimization is prioritized.

All three substitutes maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory alignment with the original part.

Frequently Asked Questions (FAQ)

Q: Can SST25VF020B-80-4I-SAE directly replace AT25DF021-SSH-T without firmware modification?

A: Yes. Both parts share identical memory capacity (2Mbit), organization (256K x 8), SPI interface, voltage supply range (2.7V ~ 3.6V), operating temperature range (-40°C ~ 85°C), and 8-SOIC package specifications. The 80 MHz clock frequency of the substitute exceeds the original 70 MHz specification, maintaining backward compatibility.

Q: What is the primary difference between W25X20CLSNIG and the original AT25DF021-SSH-T?

A: The W25X20CLSNIG operates at 104 MHz compared to the original 70 MHz, providing 48% higher clock frequency. Both parts maintain identical memory specifications, SPI interface, and 8-SOIC packaging. The substitute supports lower minimum voltage (2.3V vs. 2.7V) and carries MSL Level 3 moisture sensitivity versus Level 1 for the original.

Q: Is LE25U20AMB-AH suitable for high-speed data transfer applications?

A: No. The LE25U20AMB-AH operates at 30 MHz, significantly below the original AT25DF021-SSH-T specification of 70 MHz. This substitute is appropriate for applications where data throughput requirements are modest and cost considerations are primary. The reduced clock frequency may introduce timing constraints in systems designed for the original 70 MHz specification.

Q: Are all substitute parts available in the same packaging format?

A: Yes. All three substitute parts are housed in 8-SOIC packages with 0.154" (3.90mm) width, matching the original AT25DF021-SSH-T footprint. Direct PCB layout compatibility is maintained without redesign requirements.

Q: What is the significance of MSL Level 1 versus MSL Level 3 ratings?

A: MSL Level 1 (AT25DF021-SSH-T and SST25VF020B-80-4I-SAE) indicates unlimited shelf life without moisture exposure restrictions. MSL Level 3 (W25X20CLSNIG and LE25U20AMB-AH) requires controlled storage with a 168-hour limit after moisture exposure. For high-volume manufacturing environments with extended component storage, Level 1 rated parts offer operational advantages.

Q: Which substitute part is recommended for new design implementations?

A: Selection depends on application requirements. SST25VF020B-80-4I-SAE is recommended for designs requiring performance matching or exceeding the original 70 MHz specification with superior moisture handling (MSL Level 1). W25X20CLSNIG is recommended for applications requiring maximum clock frequency (104 MHz) with extended voltage compatibility. LE25U20AMB-AH is recommended for cost-optimized applications where 30 MHz operation is sufficient.