24AA256-E/ST EEPROM Memory IC Equivalent & Substitute Parts

Part Overview

The 24AA256-E/ST is a 256Kbit I2C EEPROM memory IC manufactured by Microchip Technology, packaged in 8-TSSOP surface mount configuration. This non-volatile memory device operates across a wide supply voltage range (1.7V to 5.5V) and temperature range (-40°C to 125°C), making it suitable for industrial and consumer applications requiring persistent data storage. The part is currently active in production with RoHS3 compliance and unlimited moisture sensitivity rating.

Equivalent and substitute parts are necessary when the primary part becomes unavailable, when alternative packaging or lead times are required, or when design specifications allow for compatible alternatives from different manufacturers while maintaining functional equivalence.

Substiute Parts

24AA256-E/ST

Microchip TechnologyIn Stock: 105924AA256-E/ST Datasheet

Current PartRFQ

BR24G256FVT-3GE2

Rohm SemiconductorIn Stock: 16411BR24G256FVT-3GE2 Datasheet

MFR RecommendedRFQ

BR24T256FVT-WE2

Rohm SemiconductorIn Stock: 7372BR24T256FVT-WE2 Datasheet

MFR RecommendedRFQ

CAV24C256YE-GT3

onsemiIn Stock: 9313CAV24C256YE-GT3 Datasheet

MFR RecommendedRFQ

M24256-BFDW6TP

STMicroelectronicsIn Stock: 1648M24256-BFDW6TP Datasheet

MFR RecommendedRFQ

M24256-BRDW6TP

STMicroelectronicsIn Stock: 32484M24256-BRDW6TP Datasheet

MFR RecommendedRFQ

M24256-DRDW8TP/K

STMicroelectronicsIn Stock: 7810M24256-DRDW8TP/K Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 24AA256-E/ST is determined by the following critical parameters:

Core Functional Requirements:

• Memory Size: 256Kbit (exact match required)
• Memory Organization: 32K x 8 (exact match required)
• Memory Interface: I2C (exact match required)
• Package Type: 8-TSSOP form factor (exact match required)
• Mounting Type: Surface Mount (exact match required)

Performance Compatibility Parameters:

• Clock Frequency: 400 kHz minimum (higher frequencies are acceptable)
• Access Time: 900 ns maximum (faster access times are acceptable)
• Write Cycle Time: 5ms (standard across all candidates)
• Voltage Supply Range: Must encompass or overlap with 1.7V ~ 5.5V
• Operating Temperature: Must support -40°C minimum and 125°C maximum, or subset thereof

All substitute parts listed meet the core functional requirements. Variations in clock frequency, access time, and voltage supply range represent performance enhancements or different operational specifications that do not prevent functional substitution in applications designed for the 24AA256-E/ST.

Parameter Comparison

Engineering Selection Recommendations

All listed substitute parts maintain functional equivalence to the 24AA256-E/ST based on core memory specifications: 256Kbit capacity, 32K x 8 organization, I2C interface, and 8-TSSOP surface mount packaging.

Rohm Semiconductor Options (BR24G256FVT-3GE2, BR24T256FVT-WE2): These parts match the 400 kHz clock frequency of the primary part and maintain the same write cycle time. Operating temperature range is limited to -40°C to 85°C, which represents a narrower specification than the 24AA256-E/ST. These parts are suitable for applications where the extended 125°C upper temperature limit is not required.

onsemi Option (CAV24C256YE-GT3): This part offers enhanced performance with 1 MHz clock frequency and 400 ns access time. It maintains the full -40°C to 125°C operating temperature range and includes AEC-Q100 automotive qualification. The voltage supply range is limited to 2.5V minimum, which may restrict use in ultra-low-voltage applications below 2.5V.

STMicroelectronics Options (M24256-BFDW6TP, M24256-BRDW6TP, M24256-DRDW8TP/K): All three STMicroelectronics parts provide 1 MHz clock frequency and 450 ns access time. M24256-BFDW6TP and M24256-BRDW6TP support -40°C to 85°C operating temperature. M24256-DRDW8TP/K extends the upper temperature limit to 105°C and includes AEC-Q100 automotive qualification, making it suitable for automotive and extended-temperature applications.

Selection should be based on specific application requirements regarding operating temperature range, clock frequency performance needs, and supply voltage constraints.

Frequently Asked Questions (FAQ)

Q: Can I use a substitute part with a higher clock frequency than the 24AA256-E/ST?

A: Yes. The 24AA256-E/ST operates at 400 kHz. Substitute parts with 1 MHz clock frequency (CAV24C256YE-GT3, M24256 series) are backward compatible and will function in applications designed for 400 kHz operation. The higher clock frequency provides improved performance without compromising compatibility.

Q: What is the difference between 8-TSSOP and 8-TSSOP-B packaging?

A: Both are 8-pin thin shrink small outline packages with identical 0.173" width and 4.40mm body dimensions. The -B designation indicates a variant specification from Rohm Semiconductor. These packages are mechanically and electrically compatible for PCB assembly purposes.

Q: Are the Rohm Semiconductor parts suitable for applications requiring 125°C operation?

A: No. BR24G256FVT-3GE2 and BR24T256FVT-WE2 are rated only to 85°C maximum operating temperature. For applications requiring 125°C operation, use the 24AA256-E/ST, CAV24C256YE-GT3, or M24256-DRDW8TP/K.

Q: Which substitute part is recommended for automotive applications?

A: CAV24C256YE-GT3 and M24256-DRDW8TP/K both carry AEC-Q100 automotive qualification. M24256-DRDW8TP/K additionally supports extended temperature operation to 105°C, providing broader automotive temperature range coverage.

Q: Can I use a part with a lower voltage supply minimum than the 24AA256-E/ST?

A: Yes. The 24AA256-E/ST operates from 1.7V minimum. Substitute parts with lower minimum voltage specifications (BR24G256FVT-3GE2 and BR24T256FVT-WE2 at 1.6V) provide enhanced low-voltage capability and are fully compatible. However, parts with higher minimum voltage specifications (CAV24C256YE-GT3 at 2.5V) may not be suitable for applications requiring operation below 2.5V.

Q: What is the significance of the access time parameter in substitution?

A: Access time defines the maximum delay from address input to data output availability. The 24AA256-E/ST specifies 900 ns access time. Substitute parts with faster access times (400 ns for CAV24C256YE-GT3, 450 ns for M24256 series) provide improved read performance and are fully compatible. Slower access times would not be acceptable substitutes.