Equivalent & Substitute Parts for AT27C256R-55PI

Part Overview

The AT27C256R-55PI from Microchip Technology is a non-volatile EPROM - OTP Memory IC with a capacity of 256Kbit, organized as 32K x 8, and featuring a parallel interface. It operates at a supply voltage range of 4.5V ~ 5.5V, comes in a 28-DIP (0.600", 15.24mm) through-hole package, and provides an access time of 55 ns. The part status is "Obsolete," which makes it necessary to identify suitable alternatives for applications requiring continued procurement, ongoing design support, or maintenance.

Substiute Parts

AT27C256R-55PI

Microchip TechnologyIn Stock: 1119AT27C256R-55PI Datasheet

Current PartRFQ

AT27C256R-70PU

Microchip TechnologyIn Stock: 6959AT27C256R-70PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for AT27C256R-55PI within the EPROM - OTP Memory IC category must strictly conform to the following allowed parameters: memory type (Non-Volatile EPROM - OTP), memory size (256Kbit), memory organization (32K x 8), memory interface (Parallel), supply voltage (4.5V ~ 5.5V), operating temperature range (-40°C ~ 85°C), mounting type (Through Hole), and package (28-DIP / 28-PDIP). Substitute parts listed must demonstrate equivalence in these critical specifications to ensure compatibility and functional interchangeability, regardless of access time variation or product status.

Parameter Comparison

Engineering Selection Recommendations

The AT27C256R-55PI is designated as "Obsolete," whereas the recommended substitute AT27C256R-70PU is classified as "Active." Both parts align on critical electrical and mechanical specifications. The substitute offers ROHS3 compliance, which may satisfy updated environmental and regulatory requirements. Both components are unaffected by REACH and retain ECCN EAR99. There are no additional product certifications presented.

Frequently Asked Questions (FAQ)

Q: What are the main criteria for substituting AT27C256R-55PI with AT27C256R-70PU?
A: Substitution is based on equivalent memory type, technology, size, organization, interface, voltage, operating temperature, mounting type, and package dimensions.

Q: Does the access time difference affect compatibility?
A: Access time is a defined parameter for both models. AT27C256R-55PI provides 55 ns, while AT27C256R-70PU offers 70 ns. Compatibility is determined by whether system requirements permit the substitute’s access time.

Q: Are AT27C256R-70PU and AT27C256R-55PI mechanically interchangeable?
A: Both parts utilize a 28-DIP (0.600", 15.24mm) through-hole package, ensuring mechanical compatibility.

Q: What compliance benefits does AT27C256R-70PU offer?
A: AT27C256R-70PU is ROHS3 compliant and shares unaffected REACH status with the original part.

Q: Is the substitute current and available?
A: AT27C256R-70PU is designated as "Active" and is listed as available in inventory.