AT27C040-70PI EPROM Equivalent & Substitute Parts

Part Overview

The AT27C040-70PI is a 4Mbit 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, which necessitates identification of functionally equivalent alternatives for ongoing system support and component procurement. The AT27C040-70PI operates within the 4.5V to 5.5V supply voltage range and supports industrial temperature specifications from -40°C to 85°C.

Substiute Parts

AT27C040-70PI

Microchip TechnologyIn Stock: 1393AT27C040-70PI Datasheet

Current PartRFQ

AT27C040-70PU

Microchip TechnologyIn Stock: 2849AT27C040-70PU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT27C040-70PI is determined by strict equivalence across the following critical parameters: memory capacity (4Mbit), memory organization (512K x 8), interface type (parallel), access time (70 ns), supply voltage range (4.5V ~ 5.5V), operating temperature range (-40°C ~ 85°C), and physical package specification (32-DIP). The substitute part AT27C040-70PU maintains identical electrical and functional characteristics while differing only in packaging format (tube versus unspecified for the original part) and product status (active versus obsolete).

Parameter Comparison

Engineering Selection Recommendations

The AT27C040-70PU serves as a direct functional equivalent to the AT27C040-70PI. Both parts share identical electrical specifications, memory capacity, access timing, voltage requirements, and physical package dimensions. The primary distinction lies in product lifecycle status: the AT27C040-70PI is obsolete while the AT27C040-70PU maintains active production status. Additionally, the AT27C040-70PU achieves ROHS3 compliance, whereas the AT27C040-70PI is RoHS non-compliant. For new designs or system refreshes, the AT27C040-70PU is the appropriate selection. For legacy system maintenance requiring exact part matching, the AT27C040-70PI remains functionally interchangeable where inventory permits.

Frequently Asked Questions (FAQ)

Q: Can AT27C040-70PU replace AT27C040-70PI in existing applications? A: Yes. Both parts are electrically and functionally identical across all critical parameters including memory capacity, access time, voltage supply, temperature range, and package configuration. Direct substitution is supported at the circuit level.

Q: What is the difference between the two part numbers? A: The primary differences are packaging format (tube for -70PU) and product status (-70PU is active production while -70PI is obsolete). The -70PU also carries ROHS3 compliance certification.

Q: Are there any compatibility concerns with the 32-DIP package? A: No. Both parts use identical 32-DIP (0.600", 15.24mm) through-hole packages. PCB layouts and socket compatibility are fully maintained.

Q: Does the RoHS compliance difference affect electrical performance? A: No. RoHS compliance relates to material composition and environmental standards, not electrical function. Both parts deliver identical performance characteristics.

Q: What is the access time specification and why does it matter? A: Both parts specify 70 ns access time, which defines the maximum delay from address input to valid data output. This parameter must match system timing requirements and cannot be substituted with faster or slower variants.