AT27C020-70PC Equivalent & Substitute Parts

Part Overview

The AT27C020-70PC 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 available in active variants with improved specifications and compliance certifications.

Substiute Parts

AT27C020-70PC

Microchip TechnologyIn Stock: 2530AT27C020-70PC Datasheet

Current PartRFQ

AT27C020-55PU

Microchip TechnologyIn Stock: 7366AT27C020-55PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT27C020-70PC is determined by the following critical parameters that must remain constant or improve:

• Memory Capacity & Organization: 2Mbit, 256K x 8 configuration
• Interface Type: Parallel interface
• Package & Pinout: 32-DIP (0.600", 15.24mm) with identical pin configuration
• Voltage Supply Range: 4.5V ~ 5.5V compatibility
• Physical Mounting: Through-hole mounting

The AT27C020-55PU qualifies as a direct substitute because it maintains identical memory specifications, package geometry, and electrical interface while offering improved access time (55 ns vs. 70 ns) and extended operating temperature range.

Parameter Comparison

Engineering Selection Recommendations

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

• Product Status: The AT27C020-55PU is classified as active, ensuring continued availability and supply chain reliability.
• Compliance: The substitute achieves ROHS3 compliance, meeting modern regulatory requirements that the original part does not satisfy.
• Performance: The 55 ns access time provides improved speed performance compared to the 70 ns specification of the main part, with no negative impact on system compatibility.
• Temperature Range: The extended operating temperature range (-40°C ~ 85°C) provides greater flexibility for applications requiring wider thermal operation.
• Electrical Compatibility: Identical voltage supply range and parallel interface ensure direct functional compatibility in existing circuit designs.
• Package Compatibility: Identical 32-DIP package dimensions and pinout enable direct socket replacement without PCB modifications.

Frequently Asked Questions (FAQ)

Q: Can the AT27C020-55PU be used as a direct replacement for the AT27C020-70PC?

A: Yes. Both parts share identical memory capacity (2Mbit), organization (256K x 8), parallel interface, voltage supply range (4.5V ~ 5.5V), and 32-DIP package geometry. The substitute offers improved access time and extended temperature range, making it functionally compatible and superior in performance.

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

A: Access time defines the maximum delay from address input to valid data output. The AT27C020-55PU's 55 ns specification is faster than the AT27C020-70PC's 70 ns specification. This improvement does not create compatibility issues; systems designed for 70 ns operation will function correctly with the faster 55 ns part.

Q: Are the packages physically identical?

A: Yes. Both parts use the 32-DIP (0.600", 15.24mm) package with identical pinout and through-hole mounting. No PCB layout changes are required for substitution.

Q: Does the extended temperature range of the AT27C020-55PU affect compatibility?

A: No. The extended operating range (-40°C ~ 85°C) is a superset of the original part's range (0°C ~ 70°C). Applications operating within the original temperature limits will function identically with the substitute.

Q: What is the significance of ROHS3 compliance on the AT27C020-55PU?

A: ROHS3 compliance indicates the substitute meets current environmental and regulatory standards for hazardous substance restrictions. The original AT27C020-70PC is non-compliant with these standards, making the substitute necessary for applications subject to modern regulatory requirements.

Q: Are there any electrical interface differences between these parts?

A: No. Both parts operate on identical 4.5V ~ 5.5V supply voltage and use parallel interface architecture. No circuit modifications are required for substitution.