AT27C020-12PC EPROM Memory IC - Equivalent & Substitute Parts

Part Overview

The AT27C020-12PC is a 2Mbit parallel EPROM (Erasable Programmable Read-Only Memory) manufactured by Microchip Technology in a 32-DIP package. This component is classified as obsolete, indicating it has been discontinued and is no longer in active production. The part operates with a 120 ns access time and requires a 4.5V to 5.5V supply voltage. Due to its obsolete status, identifying compatible substitute parts is essential for system maintenance, legacy equipment repair, and design continuity where this memory IC is specified.

Substiute Parts

AT27C020-12PC

Microchip TechnologyIn Stock: 2164AT27C020-12PC Datasheet

Current PartRFQ

AT27C020-90PU

Microchip TechnologyIn Stock: 1362AT27C020-90PU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the AT27C020-12PC is determined by strict alignment with the following critical parameters:

• Memory Capacity & Organization: Must be 2Mbit with 256K x 8 organization to maintain address and data bus compatibility
• Memory Interface: Must be parallel interface to ensure direct pin-level compatibility
• Package & Mounting: Must be 32-DIP (0.600", 15.24mm) through-hole to fit existing PCB layouts without modification
• Voltage Supply Range: Must operate within 4.5V ~ 5.5V to maintain power supply compatibility
• Access Time: Substitute parts with equal or faster access time (≤120 ns) are functionally compatible; faster access times do not create incompatibility

The AT27C020-90PU meets all substitution criteria, offering improved performance characteristics while maintaining full electrical and mechanical compatibility with the original AT27C020-12PC specification.

Parameter Comparison

Engineering Selection Recommendations

The AT27C020-90PU is a direct substitute for the AT27C020-12PC based on the following engineering criteria:

Electrical Compatibility: Both parts share identical memory capacity (2Mbit), organization (256K x 8), parallel interface, and supply voltage range (4.5V ~ 5.5V). The AT27C020-90PU provides faster access time (90 ns versus 120 ns), which does not create incompatibility and improves system performance margins.

Mechanical Compatibility: Both parts use the 32-DIP through-hole package with identical physical dimensions (0.600", 15.24mm), enabling direct PCB socket replacement without layout modification.

Product Status & Compliance: The AT27C020-90PU is in active production status, ensuring availability and supply chain continuity. The substitute achieves ROHS3 compliance, whereas the original AT27C020-12PC is non-compliant. The AT27C020-90PU also supports an extended operating temperature range (-40°C ~ 85°C versus 0°C ~ 70°C), providing greater environmental flexibility.

Programmability: The AT27C020-90PU is verified as programmable through DiGi-Electronics, confirming functional programming capability for OTP (One-Time Programmable) applications.

Frequently Asked Questions (FAQ)

Q: Can the AT27C020-90PU directly replace the AT27C020-12PC without PCB modification?

A: Yes. Both parts use the 32-DIP through-hole package with identical pin spacing and physical dimensions. Direct socket substitution is possible without PCB layout changes.

Q: What is the difference between the 120 ns and 90 ns access time specifications?

A: Access time defines the maximum delay from address input to valid data output. The AT27C020-90PU's 90 ns access time is faster than the AT27C020-12PC's 120 ns specification. Faster access time does not create incompatibility; it improves timing margins in the system.

Q: Are the supply voltage requirements identical?

A: Yes. Both parts operate within the 4.5V ~ 5.5V supply voltage range, ensuring compatibility with existing power supply designs.

Q: Why is the AT27C020-12PC listed as obsolete?

A: The AT27C020-12PC has been discontinued by the manufacturer. The AT27C020-90PU is the active production equivalent, offering improved specifications and compliance certifications.

Q: Does the extended temperature range of the AT27C020-90PU (-40°C ~ 85°C) affect compatibility?

A: No. The extended temperature range is a superset of the original specification (0°C ~ 70°C). Systems designed for the original temperature range operate within the substitute's rated range without modification.

Q: What is the significance of ROHS3 compliance on the AT27C020-90PU?

A: ROHS3 compliance indicates the part meets Restriction of Hazardous Substances regulations, restricting lead and other hazardous materials. This is relevant for applications subject to environmental or regulatory requirements. The original AT27C020-12PC is non-compliant.

Q: Are both parts One-Time Programmable (OTP)?

A: Yes. Both parts are EPROM OTP memory devices. The AT27C020-90PU is verified as programmable through DiGi-Electronics, confirming functional OTP capability.