AT27C256R-70PI EPROM Equivalent & Substitute Parts

Part Overview

The AT27C256R-70PI is a 256Kbit parallel EPROM (Erasable Programmable Read-Only Memory) manufactured by Microchip Technology in a 28-DIP package with 70 ns access time. This part is classified as obsolete, making substitute components necessary for new designs and ongoing production support. The AT27C256R-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

AT27C256R-70PI

Microchip TechnologyIn Stock: 3232AT27C256R-70PI Datasheet

Current PartRFQ

AT27C256R-70PU

Microchip TechnologyIn Stock: 6959AT27C256R-70PU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the AT27C256R-70PI is determined by strict equivalence across the following parameters: memory capacity (256Kbit), memory organization (32K x 8), parallel interface architecture, access time specification (70 ns), supply voltage range (4.5V ~ 5.5V), operating temperature range (-40°C ~ 85°C), and physical package format (28-DIP through-hole). The substitute part must maintain identical electrical characteristics and pinout compatibility to ensure direct replacement without circuit modification.

Parameter Comparison

Engineering Selection Recommendations

The AT27C256R-70PU serves as the direct functional equivalent to the AT27C256R-70PI. Both parts share identical electrical specifications, memory architecture, and physical packaging. The primary distinction is product status: the AT27C256R-70PI is obsolete while the AT27C256R-70PU maintains active production status. The AT27C256R-70PU additionally achieves ROHS3 compliance, whereas the AT27C256R-70PI is RoHS non-compliant. For new designs and production continuity, the AT27C256R-70PU is the appropriate selection. Both parts are supplied by Microchip Technology and maintain equivalent performance characteristics across all specified operating parameters.

Frequently Asked Questions (FAQ)

Q: Can the AT27C256R-70PU directly replace the AT27C256R-70PI without circuit modification?

A: Yes. Both parts are electrically and mechanically identical across all specified parameters including memory capacity, access time, voltage supply, operating temperature range, and 28-DIP package configuration. Direct substitution is possible without circuit redesign.

Q: What is the difference between the AT27C256R-70PI and AT27C256R-70PU?

A: The parts are functionally equivalent. The AT27C256R-70PI is classified as obsolete, while the AT27C256R-70PU maintains active production status. The AT27C256R-70PU also achieves ROHS3 compliance. Packaging differs: AT27C256R-70PU is supplied in tube format.

Q: Are there any performance differences between these parts?

A: No. Both parts deliver identical performance: 256Kbit capacity, 32K x 8 organization, 70 ns access time, 4.5V to 5.5V supply voltage, and -40°C to 85°C operating temperature range.

Q: Why should I use the AT27C256R-70PU instead of the AT27C256R-70PI?

A: The AT27C256R-70PI is obsolete and subject to availability constraints. The AT27C256R-70PU is actively manufactured, ensuring reliable supply for production and maintenance applications. Additionally, ROHS3 compliance of the AT27C256R-70PU aligns with current environmental and regulatory standards.

Q: Is the 28-DIP package compatible with my existing PCB design?

A: Both parts use the 28-DIP (0.600", 15.24mm) through-hole package. If your PCB accommodates this package format, both parts are mechanically compatible without modification.