AT27C020-70PI EPROM Equivalent & Substitute Parts

Part Overview

The AT27C020-70PI is a 2Mbit parallel EPROM (Erasable Programmable Read-Only Memory) manufactured by Microchip Technology in a 32-DIP package with 70 ns access time. This part is classified as obsolete, making substitute components necessary for new designs, repairs, or production continuity. The AT27C020 series remains in active production under alternative speed grades, enabling direct functional replacement while maintaining full electrical and mechanical compatibility.

Substiute Parts

AT27C020-70PI

Microchip TechnologyIn Stock: 1037AT27C020-70PI Datasheet

Current PartRFQ

AT27C020-55PU

Microchip TechnologyIn Stock: 7366AT27C020-55PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT27C020-70PI is based on the following critical parameters that must remain constant:

• Memory capacity: 2Mbit (256K x 8 organization)
• Memory interface: Parallel
• Package: 32-DIP (0.600", 15.24mm)
• Voltage supply range: 4.5V ~ 5.5V
• Operating temperature range: -40°C ~ 85°C
• Mounting type: Through Hole

The AT27C020-55PU qualifies as a direct substitute because it maintains identical values for all parameters listed above. The access time specification (55 ns vs. 70 ns) represents an improvement in performance and does not create incompatibility. Faster access time is a backward-compatible enhancement in this application context.

Parameter Comparison

Engineering Selection Recommendations

The AT27C020-55PU is the appropriate substitute for the obsolete AT27C020-70PI based on the following factors:

• Both parts are manufactured by Microchip Technology and share the same base product number (AT27C020), ensuring design continuity.
• The substitute maintains all critical electrical parameters: memory capacity, interface type, voltage supply range, and operating temperature range.
• The substitute maintains identical mechanical compatibility: 32-DIP package, 0.600" (15.24mm) body width, and through-hole mounting.
• The AT27C020-55PU is classified as active product status, ensuring long-term availability and supply chain reliability.
• The AT27C020-55PU achieves ROHS3 compliance, meeting current regulatory requirements, whereas the original part is RoHS non-compliant.
• The faster access time (55 ns) of the substitute provides performance improvement without creating any functional incompatibility.

Frequently Asked Questions (FAQ)

Q: Can the AT27C020-55PU be used as a direct replacement for the AT27C020-70PI in existing designs?

A: Yes. The AT27C020-55PU is a direct pin-for-pin and functionally compatible replacement. All electrical parameters, package dimensions, and mounting characteristics are identical. The faster access time is a performance enhancement that does not create incompatibility.

Q: What is the difference between the 70 ns and 55 ns access time specifications?

A: Access time refers to the delay between address input and valid data output. The AT27C020-55PU (55 ns) responds faster than the AT27C020-70PI (70 ns). This faster response is backward compatible and does not require circuit modifications.

Q: Are there any compliance differences between these parts?

A: Yes. The AT27C020-70PI is RoHS non-compliant, while the AT27C020-55PU is ROHS3 compliant. If your application or region requires RoHS compliance, the substitute part meets these requirements.

Q: Will the AT27C020-55PU fit in the same PCB footprint as the AT27C020-70PI?

A: Yes. Both parts use the 32-DIP package with identical dimensions (0.600" or 15.24mm body width). Through-hole mounting is identical, and no PCB layout modifications are required.

Q: What is the memory capacity and organization of these parts?

A: Both parts provide 2Mbit of memory organized as 256K x 8 (256,000 locations of 8 bits each). The parallel interface provides simultaneous access to all 8 data bits.

Q: Are these parts suitable for new designs?

A: The AT27C020-70PI is obsolete and not recommended for new designs. The AT27C020-55PU is active product and is the appropriate choice for new applications requiring 2Mbit parallel EPROM functionality.