AT28C64X-25PI Equivalent & Substitute Parts

Part Overview

The AT28C64X-25PI is a 64Kbit parallel EEPROM memory IC manufactured by Microchip Technology, housed in a 28-DIP package with 250 ns access time. This part is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing system support and new designs. The obsolete status makes sourcing direct replacements critical for maintenance and production continuity.

Substiute Parts

AT28C64X-25PI

Microchip TechnologyIn Stock: 892AT28C64X-25PI Datasheet

Current PartRFQ

AT28C64B-15PU

Microchip TechnologyIn Stock: 3411AT28C64B-15PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT28C64X-25PI is determined by the following critical parameters:

• Memory capacity (64Kbit) and organization (8K x 8) must remain identical
• Memory format must be EEPROM with parallel interface
• Package type must be 28-DIP with matching physical dimensions (0.600", 15.24mm)
• Voltage supply range must encompass 4.5V ~ 5.5V
• Operating temperature range must cover -40°C ~ 85°C
• Access time and write cycle time may vary, provided the substitute meets or exceeds performance requirements

The AT28C64B-15PU meets all substitution criteria. It maintains identical memory capacity, organization, format, interface, package, voltage, and temperature specifications. The faster access time (150 ns versus 250 ns) and extended write cycle time (10 ms versus 1 ms) represent performance improvements and compatibility enhancements respectively.

Parameter Comparison

Engineering Selection Recommendations

The AT28C64B-15PU is the direct substitute for the AT28C64X-25PI. Selection of this substitute is supported by:

• Active product status ensures long-term availability and supply chain stability
• ROHS3 compliance meets current environmental and regulatory requirements, whereas the original part is non-compliant
• Identical electrical and mechanical specifications guarantee pin-for-pin and functional compatibility
• Faster access time (150 ns) provides performance margin over the original specification
• Through-hole 28-DIP package maintains compatibility with existing PCB designs

Frequently Asked Questions (FAQ)

Q: Can the AT28C64B-15PU be used as a direct replacement for the AT28C64X-25PI?

A: Yes. Both parts share identical memory capacity (64Kbit), organization (8K x 8), interface (parallel EEPROM), package type (28-DIP), voltage supply range (4.5V ~ 5.5V), and operating temperature range (-40°C ~ 85°C). The substitute is pin-compatible and functionally equivalent.

Q: What are the differences between these two parts?

A: The AT28C64B-15PU offers faster access time (150 ns versus 250 ns) and extended write cycle time (10 ms versus 1 ms). The substitute is ROHS3 compliant, whereas the original is non-compliant. The substitute has active product status, ensuring continued availability.

Q: Are there any timing considerations when substituting these parts?

A: The faster access time of the AT28C64B-15PU (150 ns) is superior to the original specification (250 ns). The extended write cycle time (10 ms) is acceptable for EEPROM applications where write operations are typically infrequent. No timing conflicts arise from this substitution.

Q: Will the AT28C64B-15PU work in existing PCB designs?

A: Yes. The 28-DIP package dimensions (0.600", 15.24mm) and through-hole mounting type are identical. No PCB modifications are required.

Q: What is the significance of RoHS compliance?

A: ROHS3 compliance indicates the substitute meets current environmental regulations restricting hazardous substances. The original AT28C64X-25PI is non-compliant with modern standards, making the compliant substitute preferable for new designs and regulatory adherence.