AT28C64X-20PI Equivalent & Substitute Parts

Part Overview

The AT28C64X-20PI 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, making substitute components necessary for new designs and ongoing production support. The AT28C64X-20PI operates across the industrial temperature range of -40°C to 85°C with a supply voltage of 4.5V to 5.5V, serving applications requiring non-volatile parallel memory storage.

Substiute Parts

AT28C64X-20PI

Microchip TechnologyIn Stock: 1082AT28C64X-20PI Datasheet

Current PartRFQ

AT28C64B-15PU

Microchip TechnologyIn Stock: 3411AT28C64B-15PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT28C64X-20PI is based on the following critical parameters that must remain constant or improve:

• Memory capacity: 64Kbit (8K x 8 organization)
• Memory type: EEPROM, non-volatile
• Interface: Parallel
• Package: 28-DIP form factor with identical pinout
• Voltage supply range: 4.5V ~ 5.5V
• Operating temperature range: -40°C ~ 85°C
• Mounting: Through Hole

The AT28C64B-15PU qualifies as a direct substitute because it maintains identical memory capacity, organization, interface type, package form factor, voltage specifications, and temperature range. The substitute part offers improved access time (150 ns versus 200 ns) and extended write cycle time (10 ms versus 1 ms), representing a performance enhancement in read operations while maintaining full functional compatibility.

Parameter Comparison

Engineering Selection Recommendations

The AT28C64B-15PU is the qualified substitute for the AT28C64X-20PI based on the following factors:

The AT28C64X-20PI is obsolete, creating supply chain risk for production and maintenance applications. The AT28C64B-15PU maintains active product status with verified availability, ensuring long-term sourcing capability.

The AT28C64B-15PU achieves ROHS3 compliance, whereas the AT28C64X-20PI is non-compliant. For applications subject to RoHS regulations or environmental standards, the substitute part satisfies compliance requirements.

Both parts share identical electrical specifications for memory capacity, organization, interface, voltage supply, and operating temperature range. The 28-DIP package and through-hole mounting are identical, enabling direct board-level substitution without layout modifications.

The AT28C64B-15PU provides faster read access time (150 ns) compared to the original part (200 ns), representing a performance improvement for timing-critical applications. The extended write cycle time (10 ms) does not impact functional compatibility in standard EEPROM write operations.

Frequently Asked Questions (FAQ)

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

A: Yes. Both parts maintain identical memory capacity (64Kbit), organization (8K x 8), parallel interface, 28-DIP package form factor, voltage supply range (4.5V ~ 5.5V), and operating temperature range (-40°C ~ 85°C). Direct substitution is possible without circuit modifications.

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

A: The AT28C64X-20PI has 200 ns access time, while the AT28C64B-15PU has 150 ns access time. The substitute part offers faster read operations. Both access times are within standard EEPROM performance parameters.

Q: Does the write cycle time difference affect compatibility?

A: The AT28C64X-20PI specifies 1 ms write cycle time, while the AT28C64B-15PU specifies 10 ms. Both values represent acceptable EEPROM write performance. The longer write cycle time in the substitute part does not create functional incompatibility; it reflects different internal write algorithm implementation.

Q: Are the package dimensions identical?

A: Yes. Both parts use the 28-DIP package with 0.600" (15.24mm) body width. Pin spacing, lead configuration, and through-hole mounting characteristics are identical, enabling direct PCB substitution.

Q: What is the significance of RoHS compliance difference?

A: The AT28C64X-20PI is RoHS non-compliant, while the AT28C64B-15PU is ROHS3 compliant. For applications subject to RoHS regulations or customer requirements, the substitute part satisfies environmental and material composition standards.

Q: Why is product status important for this substitution?

A: The AT28C64X-20PI is classified as obsolete, indicating discontinued manufacturing and limited future availability. The AT28C64B-15PU maintains active status with current production, ensuring reliable long-term sourcing for new designs and production support.