AT28C64X-20PC Equivalent & Substitute Parts

Part Overview

The AT28C64X-20PC is a 64Kbit parallel EEPROM memory IC manufactured by Microchip Technology, housed in a 28-DIP package with 200 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-20PC

Microchip TechnologyIn Stock: 959AT28C64X-20PC Datasheet

Current PartRFQ

AT28C64B-15PU

Microchip TechnologyIn Stock: 3411AT28C64B-15PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT28C64X-20PC is determined by the following critical parameters:

• Memory capacity (64Kbit) and organization (8K x 8)
• Parallel interface architecture
• Package compatibility (28-DIP form factor)
• Supply voltage range (4.5V ~ 5.5V)
• Pin-to-pin mechanical compatibility

The AT28C64B-15PU qualifies as a direct substitute based on identical memory capacity, organization, interface type, and package footprint. Both parts share the same base product number (AT28C64) and are manufactured by Microchip Technology, ensuring functional equivalence at the system level.

Parameter Comparison

Engineering Selection Recommendations

The AT28C64B-15PU is the direct functional equivalent for the obsolete AT28C64X-20PC. Selection of this substitute is supported by:

• Active product status, ensuring long-term availability and supply chain stability
• ROHS3 compliance, meeting current environmental and regulatory requirements
• Identical memory capacity, organization, and parallel interface
• Pin-compatible 28-DIP package for direct board-level replacement
• Matching supply voltage specification (4.5V ~ 5.5V)
• Improved access time (150 ns vs. 200 ns) providing performance headroom
• Extended operating temperature range (-40°C ~ 85°C vs. 0°C ~ 70°C) for broader application flexibility

The AT28C64B-15PU is suitable for direct substitution in applications currently using the AT28C64X-20PC.

Frequently Asked Questions (FAQ)

Q: Can the AT28C64B-15PU replace the AT28C64X-20PC in existing designs?

A: Yes. Both parts share identical memory capacity (64Kbit), organization (8K x 8), parallel interface, and 28-DIP package footprint. Pin-to-pin compatibility is maintained, allowing direct board-level substitution.

Q: What are the differences in access time between these parts?

A: The AT28C64X-20PC has 200 ns access time, while the AT28C64B-15PU has 150 ns access time. The substitute is faster, which is compatible with systems designed for the original part.

Q: How do the write cycle times differ?

A: The AT28C64X-20PC specifies 1 ms write cycle time, while the AT28C64B-15PU specifies 10 ms. System designs must accommodate the longer write cycle time of the substitute if timing-critical write operations are present.

Q: Are the supply voltage requirements the same?

A: Yes. Both parts operate on 4.5V ~ 5.5V supply voltage, requiring no power supply modifications for substitution.

Q: What is the temperature operating range difference?

A: The AT28C64X-20PC operates from 0°C to 70°C, while the AT28C64B-15PU operates from -40°C to 85°C. The substitute supports a wider temperature range, suitable for extended environmental applications.

Q: Is the AT28C64B-15PU RoHS compliant?

A: Yes. The AT28C64B-15PU is ROHS3 compliant, meeting current environmental standards. The original AT28C64X-20PC is RoHS non-compliant.

Q: Are there packaging differences?

A: Both parts use 28-DIP (0.600", 15.24mm) packages. The AT28C64B-15PU is supplied in tube packaging, while the original part packaging is not specified. The package footprint and pin configuration are identical.