25AA256XT-I/ST EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 25AA256XT-I/ST is a 256Kbit Serial Peripheral Interface (SPI) EEPROM memory IC manufactured by Microchip Technology in 8-TSSOP surface mount packaging. This non-volatile memory device operates at 10 MHz clock frequency with a supply voltage range of 1.8V to 5.5V and is rated for industrial temperature range (-40°C to 85°C). The device is currently in active product status with ROHS3 compliance and unlimited moisture sensitivity level (MSL 1).

Equivalent and substitute parts are identified based on matching core electrical and mechanical specifications: 256Kbit memory capacity, 32K x 8 organization, SPI interface, 8-TSSOP package, compatible voltage supply ranges, and overlapping operating temperature specifications.

Substiute Parts

25AA256XT-I/ST

Microchip TechnologyIn Stock: 95425AA256XT-I/ST Datasheet

Current PartRFQ

AT25256B-XHL-B

Microchip TechnologyIn Stock: 2184AT25256B-XHL-B Datasheet

MFR RecommendedRFQ

CAT25256YI-GT3

onsemiIn Stock: 1901CAT25256YI-GT3 Datasheet

MFR RecommendedRFQ

CAV25256YE-GT3

onsemiIn Stock: 3329CAV25256YE-GT3 Datasheet

MFR RecommendedRFQ

M95256-DFDW6TP

STMicroelectronicsIn Stock: 2904M95256-DFDW6TP Datasheet

MFR RecommendedRFQ

M95256-DRDW3TP/K

STMicroelectronicsIn Stock: 2174M95256-DRDW3TP/K Datasheet

MFR RecommendedRFQ

M95256-DRDW8TP/K

STMicroelectronicsIn Stock: 17755M95256-DRDW8TP/K Datasheet

MFR RecommendedRFQ

M95256-RDW6TP

STMicroelectronicsIn Stock: 20613M95256-RDW6TP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following core parameters:

• Memory capacity and organization (256Kbit, 32K x 8)
• Interface protocol (SPI)
• Package type and dimensions (8-TSSOP)
• Voltage supply compatibility (minimum 1.8V, maximum 5.5V)
• Operating temperature range overlap (minimum -40°C)

Substitute parts are grouped into two categories based on clock frequency capability:

Category A - 10 MHz Operation: Parts with 10 MHz clock frequency matching the original specification. These are direct functional equivalents with identical performance characteristics.

Category B - 20 MHz Operation: Parts with 20 MHz clock frequency. These provide enhanced performance with faster SPI communication while maintaining backward compatibility with 10 MHz applications.

Category C - Automotive Grade: Parts qualified to AEC-Q100 automotive standards with extended temperature ranges (-40°C to 105°C or 125°C). These are suitable for automotive and industrial applications requiring higher reliability qualification.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (10 MHz Operation): CAV25256YE-GT3 is the only substitute maintaining 10 MHz clock frequency. This part is suitable for applications requiring identical performance characteristics. Note that CAV25256YE-GT3 has a reduced minimum voltage supply of 2.5V and extended operating temperature to 125°C with AEC-Q100 automotive qualification.

For Enhanced Performance (20 MHz Operation): AT25256B-XHL-B, CAT25256YI-GT3, M95256-DFDW6TP, M95256-RDW6TP are industrial-grade alternatives operating at 20 MHz. These parts are backward compatible with 10 MHz applications and provide faster SPI communication capability. All maintain the 1.8V minimum supply voltage and -40°C to 85°C operating range.

For Automotive and Extended Temperature Applications: M95256-DRDW3TP/K and M95256-DRDW8TP/K are AEC-Q100 qualified automotive-grade parts with 20 MHz operation and extended temperature ranges (-40°C to 125°C and -40°C to 105°C respectively). M95256-DRDW3TP/K offers improved write cycle time of 4ms compared to the original 5ms specification.

Voltage Supply Consideration: M95256-DFDW6TP supports the lowest minimum supply voltage at 1.7V, providing additional margin for low-voltage applications. CAV25256YE-GT3 requires minimum 2.5V supply and is not suitable for applications operating below this threshold.

Frequently Asked Questions (FAQ)

Q: Can AT25256B-XHL-B replace 25AA256XT-I/ST in existing designs? A: Yes. AT25256B-XHL-B is a direct functional substitute with identical memory capacity, organization, package, and voltage supply range. The 20 MHz clock frequency is backward compatible with 10 MHz applications. Verify that your application does not depend on the specific 10 MHz maximum frequency specification.

Q: What is the difference between industrial and automotive-grade parts? A: Automotive-grade parts (CAV25256YE-GT3, M95256-DRDW3TP/K, M95256-DRDW8TP/K) carry AEC-Q100 qualification and are tested to higher reliability standards. These parts feature extended operating temperature ranges and are required for automotive applications. Industrial-grade parts are suitable for consumer and industrial applications within their specified temperature ranges.

Q: Is CAV25256YE-GT3 compatible with 1.8V supply voltage? A: No. CAV25256YE-GT3 requires minimum 2.5V supply voltage. This part is not suitable for applications operating at 1.8V. Use AT25256B-XHL-B, CAT25256YI-GT3, M95256-DFDW6TP, M95256-DRDW3TP/K, M95256-DRDW8TP/K, or M95256-RDW6TP for 1.8V minimum supply applications.

Q: What packaging options are available for these substitutes? A: All substitute parts use 8-TSSOP surface mount package with identical 0.173" width and 4.40mm dimensions. Packaging format varies: Tube, Cut Tape & Digi-Reel, or Tape & Reel. Verify packaging availability with your supplier for production requirements.

Q: Can M95256-DRDW8TP/K operate at 125°C? A: No. M95256-DRDW8TP/K is rated for -40°C to 105°C operating temperature. For 125°C operation, use M95256-DRDW3TP/K which is qualified to -40°C to 125°C.

Q: Which substitute offers the fastest write cycle time? A: M95256-DRDW3TP/K and M95256-DRDW8TP/K both offer 4ms write cycle time, compared to 5ms for the original 25AA256XT-I/ST and most other substitutes. This represents a 20% improvement in write performance.