AT28C64-20PC Equivalent & Substitute Parts

Part Overview

The AT28C64-20PC 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 AT28C64-20PC remains in stock inventory but is no longer in active production, making substitute parts critical for long-term component availability and supply chain continuity.

Substiute Parts

AT28C64-20PC

Microchip TechnologyIn Stock: 1486AT28C64-20PC Datasheet

Current PartRFQ

AT28C64B-15PU

Microchip TechnologyIn Stock: 3411AT28C64B-15PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT28C64-20PC is determined by the following critical parameters that must remain compatible:

• Memory Capacity & Organization: 64Kbit capacity with 8K x 8 organization is mandatory for address and data bus compatibility
• Memory Interface: Parallel interface is required for direct pin-to-pin compatibility
• Package & Pinout: 28-DIP package with identical physical dimensions (0.600", 15.24mm) ensures mechanical and electrical socket compatibility
• Voltage Supply Range: 4.5V ~ 5.5V compatibility ensures operation within the same power supply specifications
• Access Time: Substitute parts with equal or faster access time (≤200 ns) maintain or improve system timing performance

The AT28C64B-15PU meets all substitution criteria with improved specifications including faster access time (150 ns), extended operating temperature range (-40°C ~ 85°C), and active product status with RoHS3 compliance.

Parameter Comparison

Engineering Selection Recommendations

The AT28C64B-15PU is the qualified substitute for the AT28C64-20PC based on the following engineering criteria:

• Functional Compatibility: Identical memory capacity, organization, and parallel interface ensure direct functional replacement without circuit modification
• Pin Compatibility: Both parts use the 28-DIP package with identical pinout, enabling direct socket substitution
• Electrical Compatibility: Both parts operate within the same 4.5V ~ 5.5V supply voltage range
• Performance Enhancement: The AT28C64B-15PU provides faster access time (150 ns vs. 200 ns), improving system timing margins
• Product Status & Compliance: The AT28C64B-15PU is in active production with RoHS3 compliance, ensuring long-term availability and regulatory alignment
• Temperature Range Extension: The AT28C64B-15PU supports -40°C ~ 85°C operation, exceeding the original part's 0°C ~ 70°C range for broader application environments

Frequently Asked Questions (FAQ)

Q: Can the AT28C64B-15PU be used as a direct replacement for the AT28C64-20PC?

A: Yes. Both parts share identical memory capacity (64Kbit), organization (8K x 8), parallel interface, and 28-DIP package pinout. The AT28C64B-15PU can be inserted directly into existing sockets without circuit modification.

Q: What are the key differences between these parts?

A: The AT28C64B-15PU offers faster access time (150 ns vs. 200 ns), extended operating temperature range (-40°C ~ 85°C vs. 0°C ~ 70°C), active product status, and RoHS3 compliance. Write cycle time differs (10 ms vs. 1 ms), but this does not affect substitution compatibility.

Q: Are there any timing considerations when substituting?

A: The AT28C64B-15PU's faster access time (150 ns) is superior to the original specification (200 ns), maintaining or improving system timing performance. No timing violations will occur in circuits designed for the AT28C64-20PC.

Q: Does the package remain the same?

A: Yes. Both parts use the 28-DIP package with identical physical dimensions (0.600", 15.24mm) and pinout, ensuring mechanical and electrical compatibility.

Q: What is the compliance status of the substitute part?

A: The AT28C64B-15PU is RoHS3 compliant and REACH unaffected, meeting current regulatory requirements. The original AT28C64-20PC is RoHS non-compliant.

Q: Is the AT28C64B-15PU currently available?

A: Yes. The AT28C64B-15PU is in active production status with verified availability in stock inventory, ensuring reliable long-term supply compared to the obsolete AT28C64-20PC.