Equivalent & Substitute Parts for 25LC040XT/ST

Part Overview

The 25LC040XT/ST is a 4Kbit EEPROM memory IC manufactured by Microchip Technology, featuring SPI interface operation at 2 MHz with 8-TSSOP surface mount packaging. This non-volatile memory device operates across a 2.5V to 5.5V supply range and supports industrial temperature specifications from 0°C to 70°C. The part is ROHS3 compliant and currently active in production with substantial inventory availability. Equivalent and substitute parts are identified to provide design flexibility, accommodate supply chain variations, and support applications requiring extended temperature ranges or higher clock frequencies.

Substiute Parts

25LC040XT/ST

Microchip TechnologyIn Stock: 1099025LC040XT/ST Datasheet

Current PartRFQ

25LC040AT-I/ST

Microchip TechnologyIn Stock: 339825LC040AT-I/ST Datasheet

MFR RecommendedRFQ

25LC040XT-I/ST

Microchip TechnologyIn Stock: 355425LC040XT-I/ST 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 25LC040XT/ST is determined by strict alignment across the following critical parameters: 4Kbit memory capacity, 512 x 8 memory organization, SPI interface protocol, 8-TSSOP package footprint, and surface mount mounting type. All identified substitute parts maintain these core specifications. Clock frequency variations (2 MHz to 20 MHz) are permissible as higher frequencies remain backward compatible with 2 MHz operation. Supply voltage ranges may extend to lower minimums (1.7V or 1.8V) while maintaining the 5.5V maximum, ensuring compatibility in applications operating within the original 2.5V to 5.5V window. Operating temperature ranges may extend beyond the original 0°C to 70°C specification, providing enhanced performance margins. Write cycle time remains constant at 4ms to 5ms across all qualified substitutes. All substitute parts maintain ROHS3 compliance and identical HTSUS and ECCN classifications.

Parameter Comparison

Engineering Selection Recommendations

Selection among equivalent and substitute parts for the 25LC040XT/ST should be based on application-specific requirements within the following framework:

For applications requiring identical electrical and thermal specifications, the 25LC040XT-I/ST provides direct substitution with extended operating temperature range (-40°C to 85°C) while maintaining 2 MHz clock frequency and identical supply voltage window.

For applications tolerating higher clock frequencies, the 25LC040AT-I/ST (10 MHz), AT25040B-XHL-T (20 MHz), CAT25040YI-GT3 (20 MHz), and all M95040 variants (20 MHz) provide enhanced performance margins. These parts maintain backward compatibility with 2 MHz operation through SPI protocol compliance.

For applications requiring extended low-voltage operation, the AT25040B-XHL-T, CAT25040YI-GT3, M95040-DFDW6TP, M95040-DRDW3TP/K, M95040-DRDW8TP/K, M95040-RDW6TP, and R1EX25004ATA00I#S0 support minimum supply voltages of 1.7V to 1.8V, compared to the original 2.5V minimum.

For automotive applications requiring AEC-Q100 qualification, the M95040-DRDW3TP/K and M95040-DRDW8TP/K are the only qualified options, with operating temperature ranges extending to 125°C and 105°C respectively.

For applications with strict supply voltage constraints matching the original 2.5V to 5.5V window, the 25LC040AT-I/ST, 25LC040XT-I/ST, and M95040-WDW6TP maintain this specification.

All substitute parts maintain ROHS3 compliance, identical HTSUS classification (8542.32.0051), and EAR99 ECCN status, ensuring regulatory equivalence.

Frequently Asked Questions (FAQ)

Q: Can the 25LC040XT/ST be replaced with a part operating at a higher clock frequency?

A: Yes. All substitute parts with clock frequencies of 5 MHz, 10 MHz, or 20 MHz are backward compatible with 2 MHz operation through SPI protocol compliance. The higher clock frequency capability does not affect operation at lower speeds.

Q: What is the minimum supply voltage compatibility for substitution?

A: The original 25LC040XT/ST operates from 2.5V to 5.5V. Substitute parts with lower minimum voltages (1.7V or 1.8V) remain compatible with applications operating within the original 2.5V to 5.5V range. However, applications requiring operation below 2.5V must select parts with extended low-voltage specifications.

Q: Are all substitute parts available in identical packaging?

A: All substitute parts use 8-TSSOP surface mount packaging with 0.173" width and 4.40mm body width, ensuring PCB footprint compatibility. Packaging format variations exist (Tape & Reel versus Cut Tape & Digi-Reel), which do not affect component functionality but may influence procurement and handling procedures.

Q: Which substitute parts are suitable for automotive applications?

A: The M95040-DRDW3TP/K and M95040-DRDW8TP/K are AEC-Q100 qualified automotive-grade parts. These parts support extended operating temperature ranges (-40°C to 125°C and -40°C to 105°C respectively) and reduced write cycle times (4ms).

Q: Does substitution require PCB redesign?

A: No. All substitute parts maintain identical 8-TSSOP package dimensions and pin configurations, eliminating the need for PCB layout modifications. Firmware or software changes are not required due to SPI protocol standardization across all parts.

Q: What is the significance of write cycle time differences?

A: Write cycle time remains constant at 4ms to 5ms across all parts. The M95040 automotive variants feature 4ms write cycles, providing marginally faster write operations compared to the 5ms specification of other parts. This difference is negligible for most applications and does not affect functional compatibility.

Q: Can parts with different temperature ratings be mixed in production?

A: Yes, provided the application's thermal environment remains within the most restrictive specification. For example, if mixing 25LC040XT/ST (0°C to 70°C) with 25LC040XT-I/ST (-40°C to 85°C), the assembly must operate within 0°C to 70°C to ensure all components function within specification.