25AA040AT-I/MC EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 25AA040AT-I/MC is a 4Kbit Serial Peripheral Interface (SPI) EEPROM memory IC manufactured by Microchip Technology. This non-volatile memory device operates at 10 MHz clock frequency with a supply voltage range of 1.8V to 5.5V and is housed in an 8-DFN (2x3) package with exposed pad. The device is actively produced and ROHS3 compliant, making it suitable for embedded systems requiring persistent data storage with SPI interface compatibility. Equivalent and substitute parts are identified based on matching memory capacity, interface protocol, voltage specifications, and package compatibility to ensure functional interchangeability in circuit designs.

Substiute Parts

25AA040AT-I/MC

Microchip TechnologyIn Stock: 80425AA040AT-I/MC Datasheet

Current PartRFQ

AT25040B-MAHL-T

Microchip TechnologyIn Stock: 2503AT25040B-MAHL-T Datasheet

MFR RecommendedRFQ

CAT25040VP2I-GT3

onsemiIn Stock: 8501CAT25040VP2I-GT3 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the 25AA040AT-I/MC are qualified based on the following critical parameters that determine functional interchangeability:

Core Compatibility Criteria:

• Memory capacity: 4Kbit (512 x 8 organization)
• Interface protocol: SPI
• Supply voltage range: 1.8V ~ 5.5V minimum overlap
• Operating temperature range: -40°C ~ 85°C minimum coverage
• Write cycle time: 5ms or faster
• Non-volatile EEPROM technology
• Surface mount package with 8-pin DFN footprint

Allowed Variations:

• Clock frequency may exceed 10 MHz (backward compatible)
• Package variants within 8-pin DFN family (VFDFN, UFDFN, TDFN, WFDFN)
• Moisture Sensitivity Level (MSL) may differ
• Packaging format (Tape & Reel, Cut Tape, Digi-Reel)
• Manufacturer differences (Microchip Technology, onsemi)

Parameter Comparison

Engineering Selection Recommendations

All three parts listed—25AA040AT-I/MC, AT25040B-MAHL-T, and CAT25040VP2I-GT3—meet the core functional requirements for 4Kbit SPI EEPROM applications. Selection between these parts should be based on the following factors:

Product Availability and Supply Chain: The CAT25040VP2I-GT3 (onsemi) offers the highest inventory availability at 8432 pieces. The AT25040B-MAHL-T (Microchip Technology) provides 2486 pieces, while the 25AA040AT-I/MC maintains 767 pieces in stock.

Compliance and Certification: All three parts are ROHS3 compliant and REACH unaffected, meeting environmental regulatory requirements. All share identical ECCN (EAR99) and HTSUS (8542.32.0051) classifications.

Moisture Sensitivity Considerations: The 25AA040AT-I/MC and CAT25040VP2I-GT3 both carry MSL rating 1 (unlimited moisture sensitivity level), indicating superior storage and handling flexibility. The AT25040B-MAHL-T carries MSL rating 3 (168 hours), requiring controlled storage conditions.

Performance Headroom: The AT25040B-MAHL-T operates at 20 MHz clock frequency, providing 2x performance margin over the 10 MHz specification of the main part. This allows for potential future design optimization without component substitution.

Package Footprint Compatibility: All three parts use 8-pin DFN packages with exposed pads in the 2x3mm footprint. Verify PCB layout compatibility with specific package variants (VFDFN, UFDFN, WFDFN) as minor dimensional differences may exist.

Frequently Asked Questions (FAQ)

Q: Can AT25040B-MAHL-T directly replace 25AA040AT-I/MC in existing designs?

A: Yes. Both parts share identical memory capacity (4Kbit), organization (512 x 8), SPI interface, voltage range (1.8V ~ 5.5V), operating temperature (-40°C ~ 85°C), and write cycle time (5ms). The AT25040B-MAHL-T operates at 20 MHz versus 10 MHz, which is a performance enhancement. Package variants (UFDFN vs VFDFN) require PCB footprint verification.

Q: What is the difference between CAT25040VP2I-GT3 and the Microchip parts?

A: CAT25040VP2I-GT3 is manufactured by onsemi rather than Microchip Technology. It maintains identical memory specifications, voltage range, temperature range, and write cycle time. The primary differences are manufacturer, package variant (WFDFN), and MSL rating (1 vs 3). All three are functionally equivalent for SPI EEPROM applications.

Q: Does clock frequency affect substitution compatibility?

A: Clock frequency does not prevent substitution. The 25AA040AT-I/MC operates at 10 MHz, while AT25040B-MAHL-T operates at 20 MHz. Higher clock frequency is backward compatible and does not create functional incompatibility. The CAT25040VP2I-GT3 clock frequency is not specified in available data but meets all other core parameters.

Q: Are there package footprint concerns when substituting between these parts?

A: All three parts use 8-pin DFN packages in 2x3mm footprint with exposed pads. However, specific package variants differ: 8-VFDFN (25AA040AT-I/MC), 8-UFDFN (AT25040B-MAHL-T), and 8-WFDFN (CAT25040VP2I-GT3). Verify PCB layout and solder pad dimensions against the specific package datasheet before substitution.

Q: What is the significance of MSL rating differences?

A: MSL (Moisture Sensitivity Level) rating indicates storage and handling requirements. MSL 1 (25AA040AT-I/MC, CAT25040VP2I-GT3) allows unlimited shelf life without moisture control. MSL 3 (AT25040B-MAHL-T) requires controlled storage at specified humidity levels for up to 168 hours after packaging. This affects supply chain logistics but not electrical performance.

Q: Are all parts ROHS3 compliant?

A: Yes. All three parts—25AA040AT-I/MC, AT25040B-MAHL-T, and CAT25040VP2I-GT3—are ROHS3 compliant and REACH unaffected, meeting environmental and regulatory requirements for commercial and industrial applications.