AT27C040-15PI Equivalent & Substitute Parts

Part Overview

The AT27C040-15PI is a 4Mbit parallel EPROM (Erasable Programmable Read-Only Memory) manufactured by Microchip Technology in a 32-DIP package with 150 ns access time. This part is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing system support and new designs. The AT27C040 series remains in use in legacy embedded systems and industrial applications where parallel EPROM technology is required.

Substiute Parts

AT27C040-15PI

Microchip TechnologyIn Stock: 1005AT27C040-15PI Datasheet

Current PartRFQ

AT27C040-90PU

Microchip TechnologyIn Stock: 1681AT27C040-90PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT27C040-15PI is determined by the following critical parameters that must remain constant:

• Memory capacity: 4Mbit
• Memory organization: 512K x 8
• Interface type: Parallel
• Package type: 32-DIP (0.600", 15.24mm)
• Voltage supply range: 4.5V ~ 5.5V
• Operating temperature range: -40°C ~ 85°C

The AT27C040-90PU qualifies as a direct substitute because it maintains identical values across all these parameters. The access time difference (90 ns versus 150 ns) represents an improvement in performance and does not create incompatibility. Both parts share the same base product number (AT27C040) and pinout configuration.

Parameter Comparison

Engineering Selection Recommendations

The AT27C040-90PU is the qualified substitute for the AT27C040-15PI. Selection of the AT27C040-90PU is supported by the following factors:

• Active product status ensures continued availability and manufacturing support
• ROHS3 compliance meets current environmental and regulatory requirements
• Faster access time (90 ns) provides performance margin over the original specification (150 ns)
• Identical pinout and package dimensions enable direct board-level replacement
• Verified programmability status confirms compatibility with standard EPROM programming equipment

The AT27C040-15PI, classified as obsolete, should be replaced with the AT27C040-90PU in new designs and system refreshes.

Frequently Asked Questions (FAQ)

Q: Can the AT27C040-90PU be used as a direct replacement for the AT27C040-15PI?

A: Yes. Both parts share identical memory capacity (4Mbit), organization (512K x 8), parallel interface, 32-DIP package, voltage supply range (4.5V ~ 5.5V), and operating temperature range (-40°C ~ 85°C). The faster access time of the AT27C040-90PU does not create incompatibility.

Q: What is the difference between the access times of these parts?

A: The AT27C040-15PI has 150 ns access time, while the AT27C040-90PU has 90 ns access time. The faster access time of the substitute part represents improved performance and maintains backward compatibility with systems designed for the original part.

Q: Are there packaging differences between these parts?

A: Both parts use 32-DIP (0.600", 15.24mm) through-hole packages. No PCB layout modifications are required for substitution.

Q: What is the significance of the product status difference?

A: The AT27C040-15PI is obsolete, meaning it is no longer manufactured. The AT27C040-90PU is active, ensuring availability for procurement and continued manufacturing support.

Q: Does RoHS compliance affect substitution?

A: The AT27C040-90PU is ROHS3 compliant, while the AT27C040-15PI is not. For applications subject to RoHS regulations or environmental requirements, the AT27C040-90PU is the required choice.