AT25256W-10SC Equivalent & Substitute Parts

Part Overview

The AT25256W-10SC is a 256Kbit EEPROM memory IC manufactured by Microchip Technology, featuring SPI interface operation at 3 MHz. This device is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing system support and new design implementations. The part operates within a 4.5V to 5.5V supply range and is housed in an 8-SOIC package suitable for surface mount applications.

Substiute Parts

AT25256W-10SC

Microchip TechnologyIn Stock: 697AT25256W-10SC Datasheet

Current PartRFQ

25AA256-E/SM

Microchip TechnologyIn Stock: 143325AA256-E/SM Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT25256W-10SC is determined by the following critical parameters:

• Memory capacity (256Kbit) and organization (32K x 8) must remain identical
• SPI interface protocol compatibility is mandatory
• Package type (8-SOIC) must match for direct board-level replacement
• Write cycle time (5ms) establishes minimum performance baseline
• Supply voltage range must encompass or exceed the original 4.5V ~ 5.5V specification
• Operating temperature range should support the original 0°C ~ 70°C minimum

The 25AA256-E/SM qualifies as a direct substitute based on these parameters. It maintains identical memory capacity, organization, SPI interface, package configuration, and write cycle time. The substitute part exceeds the original specifications in clock frequency (10 MHz vs. 3 MHz), supply voltage range (1.8V ~ 5.5V vs. 4.5V ~ 5.5V), and operating temperature range (-40°C ~ 125°C vs. 0°C ~ 70°C).

Parameter Comparison

Engineering Selection Recommendations

The 25AA256-E/SM is the qualified substitute for the AT25256W-10SC based on the following engineering criteria:

Functional Compatibility: Both devices share identical memory capacity (256Kbit), organization (32K x 8), SPI interface protocol, and package configuration (8-SOIC). Pin-level compatibility is maintained, enabling direct board-level replacement without circuit modification.

Performance Enhancement: The substitute part operates at 10 MHz clock frequency compared to the original 3 MHz, providing improved data transfer rates while maintaining backward compatibility with systems designed for the slower original specification.

Supply Voltage Compatibility: The 25AA256-E/SM operates across 1.8V to 5.5V, which encompasses the original 4.5V to 5.5V range. Systems powered within the original voltage specification will function without modification.

Temperature Range Extension: The substitute supports -40°C to 125°C operation, exceeding the original 0°C to 70°C range. This enables deployment in extended temperature environments while remaining compatible with standard industrial applications.

Compliance Status: The 25AA256-E/SM holds Active product status and ROHS3 compliance, addressing obsolescence concerns and regulatory requirements. The original AT25256W-10SC is classified as obsolete and RoHS non-compliant.

Frequently Asked Questions (FAQ)

Q: Can the 25AA256-E/SM directly replace the AT25256W-10SC on existing PCBs?

A: Yes. Both devices use identical 8-SOIC packaging and pin configuration. No circuit modifications are required for board-level substitution.

Q: Are there differences in SPI protocol implementation between these parts?

A: No. Both devices implement standard SPI interface protocol. The 25AA256-E/SM operates at higher clock frequency (10 MHz vs. 3 MHz) but maintains full backward compatibility with systems designed for the original 3 MHz specification.

Q: What is the impact of the wider supply voltage range in the substitute part?

A: The 25AA256-E/SM operates from 1.8V to 5.5V, compared to the original 4.5V to 5.5V. Systems powered within the original voltage specification will operate identically. The extended lower voltage limit enables use in low-power applications.

Q: Does the extended operating temperature range of the substitute affect reliability?

A: No. The 25AA256-E/SM supports -40°C to 125°C operation, which encompasses the original 0°C to 70°C range. Systems operating within the original temperature specification will function without degradation.

Q: What is the significance of the product status change from Obsolete to Active?

A: Active status indicates ongoing manufacturing and availability. This resolves supply chain concerns associated with the obsolete AT25256W-10SC and ensures long-term component availability for production and field replacement.

Q: Are there compliance differences between the original and substitute parts?

A: Yes. The 25AA256-E/SM is ROHS3 compliant, while the AT25256W-10SC is RoHS non-compliant. This addresses regulatory requirements for new designs and manufacturing in regions with RoHS mandates.