AT27C040-90PC EPROM Equivalent & Substitute Parts

Part Overview

The AT27C040-90PC is a 4Mbit parallel EPROM (Erasable Programmable Read-Only Memory) manufactured by Microchip Technology in a 32-DIP package with 90 ns access time. This part is classified as obsolete, which necessitates identification of active equivalent components for new designs or ongoing production requirements. The AT27C040-90PC operates within the 4.5V to 5.5V supply voltage range and is suitable for applications requiring non-volatile memory storage in legacy systems.

Substiute Parts

AT27C040-90PC

Microchip TechnologyIn Stock: 6165AT27C040-90PC Datasheet

Current PartRFQ

AT27C040-90PU

Microchip TechnologyIn Stock: 1681AT27C040-90PU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT27C040-90PC is determined by strict equivalence across the following critical parameters:

• Memory capacity (4Mbit) and organization (512K x 8)
• Parallel interface architecture
• Access time specification (90 ns)
• Supply voltage compatibility (4.5V ~ 5.5V)
• Package form factor (32-DIP)
• Through-hole mounting compatibility

The AT27C040-90PU qualifies as a direct substitute based on identical electrical specifications and package configuration. Both parts share the same base product number (AT27C040) and maintain functional equivalence across all memory and interface parameters.

Parameter Comparison

Engineering Selection Recommendations

The AT27C040-90PU is the qualified substitute for the AT27C040-90PC. Selection between these parts should be based on the following criteria:

AT27C040-90PC is suitable only for legacy system maintenance where the original part specification must be maintained and RoHS compliance is not a requirement.

AT27C040-90PU is the preferred selection for all new designs and production applications. This part is active in the product lifecycle, offers extended operating temperature range (-40°C to 85°C versus 0°C to 70°C), and meets ROHS3 compliance requirements. The wider temperature specification provides enhanced reliability across industrial and extended-temperature applications.

Both parts maintain electrical and functional equivalence, ensuring direct pin-compatible replacement without circuit modification.

Frequently Asked Questions (FAQ)

Q: Can AT27C040-90PU directly replace AT27C040-90PC in existing designs?

A: Yes. Both parts are pin-compatible with identical electrical specifications, memory capacity, access time, and supply voltage requirements. No circuit modifications are required for substitution.

Q: What is the primary difference between these two parts?

A: The AT27C040-90PU has an extended operating temperature range (-40°C to 85°C) compared to the AT27C040-90PC (0°C to 70°C), and meets ROHS3 compliance. The AT27C040-90PC is obsolete.

Q: Are there packaging differences between AT27C040-90PC and AT27C040-90PU?

A: Both parts use identical 32-DIP (0.600", 15.24mm) through-hole packaging. No PCB layout modifications are necessary.

Q: Why is the AT27C040-90PC listed as obsolete?

A: The AT27C040-90PC has been superseded by the AT27C040-90PU, which offers improved specifications and regulatory compliance. Microchip Technology maintains the AT27C040-90PU as the active product variant.

Q: Does the extended temperature range of AT27C040-90PU affect compatibility?

A: No. The extended temperature range of the AT27C040-90PU (-40°C to 85°C) is a superset of the AT27C040-90PC specification (0°C to 70°C). The substitute part operates reliably across all conditions specified for the original part and beyond.