25AA040A-I/ST EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 25AA040A-I/ST 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 512 x 8 memory organization in an 8-TSSOP surface mount package. The part is currently in active product status with 3400 units in stock. Substitute parts are necessary to address supply chain requirements, packaging preferences, performance specifications, or application-specific temperature and voltage constraints.

Substiute Parts

25AA040A-I/ST

Microchip TechnologyIn Stock: 348525AA040A-I/ST Datasheet

Current PartRFQ

AT25040B-XHL-B

Microchip TechnologyIn Stock: 2863AT25040B-XHL-B Datasheet

MFR RecommendedRFQ

AT25040B-XHL-T

Microchip TechnologyIn Stock: 18688AT25040B-XHL-T Datasheet

MFR RecommendedRFQ

CAT25040YI-GT3

onsemiIn Stock: 60383CAT25040YI-GT3 Datasheet

MFR RecommendedRFQ

M95040-DFDW6TP

STMicroelectronicsIn Stock: 4799M95040-DFDW6TP Datasheet

MFR RecommendedRFQ

M95040-DRDW3TP/K

STMicroelectronicsIn Stock: 18961M95040-DRDW3TP/K Datasheet

MFR RecommendedRFQ

M95040-DRDW8TP/K

STMicroelectronicsIn Stock: 4569M95040-DRDW8TP/K Datasheet

MFR RecommendedRFQ

M95040-RDW6TP

STMicroelectronicsIn Stock: 16047M95040-RDW6TP Datasheet

MFR RecommendedRFQ

M95040-WDW6TP

STMicroelectronicsIn Stock: 1544M95040-WDW6TP Datasheet

MFR RecommendedRFQ

R1EX25004ATA00I#S0

Renesas Electronics CorporationIn Stock: 3874R1EX25004ATA00I#S0 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 25AA040A-I/ST is determined by the following core parameters:

Critical Parameters (Must Match):

• Memory Size: 4Kbit
• Memory Organization: 512 x 8
• Memory Interface: SPI
• Package Type: 8-TSSOP (0.173", 4.40mm Width)
• Mounting Type: Surface Mount

Allowable Variation Parameters:

• Clock Frequency: May exceed 10 MHz (higher frequency is backward compatible)
• Write Cycle Time: May be equal to or less than 5ms
• Voltage Supply Range: Must encompass or match 1.8V ~ 5.5V
• Operating Temperature: May extend beyond -40°C ~ 85°C
• Packaging Format: Tube, Tape & Reel (TR), or Cut Tape (CT) & Digi-Reel®
• MSL Rating: May vary based on packaging format
• Manufacturer: Different manufacturers acceptable if specifications align

All substitute parts listed maintain identical memory capacity, organization, interface protocol, and physical package dimensions as the primary part.

Parameter Comparison

Engineering Selection Recommendations

For Standard Industrial Applications (-40°C ~ 85°C): CAT25040YI-GT3 (onsemi) offers the highest inventory availability (60300 units) with 20 MHz clock frequency, matching voltage supply range, and MSL 1 rating. AT25040B-XHL-T (Microchip Technology) provides 18647 units in Tape & Reel format with identical electrical specifications.

For Automotive Grade Requirements: M95040-DRDW3TP/K and M95040-DRDW8TP/K (STMicroelectronics) are qualified to AEC-Q100 automotive standards. M95040-DRDW3TP/K extends operating temperature to -40°C ~ 125°C with 4ms write cycle time. M95040-DRDW8TP/K operates to -40°C ~ 105°C, also with 4ms write cycle time.

For Extended Temperature Range: M95040-DRDW3TP/K supports -40°C ~ 125°C operating temperature, exceeding the primary part specification.

For Reduced Voltage Supply Applications: M95040-DFDW6TP (STMicroelectronics) operates at 1.7V minimum supply voltage, providing compatibility with lower voltage system designs.

For Restricted Voltage Supply Applications: M95040-WDW6TP (STMicroelectronics) operates at 2.5V ~ 5.5V supply range and is verified as DiGi-Electronics Programmable.

For Lower Clock Frequency Requirements: R1EX25004ATA00I#S0 (Renesas Electronics Corporation) operates at 5 MHz clock frequency, suitable for applications with reduced speed requirements.

Frequently Asked Questions (FAQ)

Q: Can I substitute the 25AA040A-I/ST with a part operating at 20 MHz instead of 10 MHz? A: Yes. Higher clock frequency is backward compatible. A 20 MHz part operates correctly in circuits designed for 10 MHz operation. The substitute will not introduce timing violations in the original application.

Q: What is the difference between Tape & Reel (TR) and Cut Tape (CT) & Digi-Reel® packaging? A: Tape & Reel (TR) is continuous reel packaging for automated assembly lines. Cut Tape (CT) & Digi-Reel® is pre-cut tape on a reel, suitable for mixed-volume production or manual assembly. Both formats contain identical components; packaging format selection depends on assembly process requirements.

Q: Are all substitute parts ROHS3 compliant? A: Yes. All listed substitute parts maintain ROHS3 compliance status, matching the primary part specification.

Q: Can I use M95040-WDW6TP if my circuit operates at 1.8V? A: No. M95040-WDW6TP has a minimum supply voltage of 2.5V and is not suitable for 1.8V operation. Select parts with 1.8V minimum supply voltage specification: 25AA040A-I/ST, AT25040B-XHL-B, AT25040B-XHL-T, CAT25040YI-GT3, M95040-DFDW6TP, M95040-DRDW3TP/K, M95040-DRDW8TP/K, M95040-RDW6TP, or R1EX25004ATA00I#S0.

Q: What does MSL 1 (Unlimited) mean compared to MSL 3 (168 Hours)? A: MSL (Moisture Sensitivity Level) indicates moisture exposure limits during storage and handling. MSL 1 (Unlimited) allows indefinite storage without moisture control. MSL 3 (168 Hours) requires moisture control and limits exposure to 168 hours at specified humidity conditions before reflow soldering. MSL 1 parts offer less stringent handling requirements.

Q: Is the 4ms write cycle time of M95040-DRDW3TP/K and M95040-DRDW8TP/K compatible with the 5ms specification of the primary part? A: Yes. Faster write cycle time (4ms versus 5ms) is a performance improvement and maintains full backward compatibility. Applications designed for 5ms write cycles operate correctly with 4ms write cycle parts.

Q: Which substitute part has the highest inventory availability? A: CAT25040YI-GT3 (onsemi) has 60300 units in stock, the highest availability among all listed substitutes.