AT28C64-20SC EEPROM Equivalent & Substitute Parts

Part Overview

The AT28C64-20SC is a 64Kbit parallel EEPROM memory IC manufactured by Microchip Technology in a 28-SOIC package. This part is classified as obsolete, making substitute components necessary for new designs and production continuity. The AT28C64-20SC operates with a 200 ns access time and supports standard 4.5V to 5.5V supply voltage across a 0°C to 70°C operating temperature range. Equivalent and substitute parts must maintain compatibility across memory capacity, interface type, package form factor, and electrical specifications.

Substiute Parts

AT28C64-20SC

Microchip TechnologyIn Stock: 7398AT28C64-20SC Datasheet

Current PartRFQ

AT28C64B-15SU

Microchip TechnologyIn Stock: 17897AT28C64B-15SU Datasheet

MFR RecommendedRFQ

X28HC64SIZ-12

Renesas Electronics CorporationIn Stock: 1230X28HC64SIZ-12 Datasheet

MFR RecommendedRFQ

X28HC64SIZ-12T1

Renesas Electronics CorporationIn Stock: 1118X28HC64SIZ-12T1 Datasheet

MFR RecommendedRFQ

X28HC64SZ-12

Renesas Electronics CorporationIn Stock: 1156X28HC64SZ-12 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the AT28C64-20SC is determined by the following critical parameters: 64Kbit memory capacity, 8K x 8 organization, parallel interface, 28-SOIC package, and 4.5V to 5.5V supply voltage compatibility. Access time and write cycle time are secondary performance metrics that may vary among substitutes while maintaining functional equivalence. All substitute parts listed maintain the same memory capacity, organization, interface type, and package specification as the original part.

The substitute parts are grouped into two categories based on operating temperature range and product status:

Category 1 (Active, Extended Temperature): AT28C64B-15SU and X28HC64SIZ-12T1 support -40°C to 85°C operating range with improved access times (150 ns and 120 ns respectively) and RoHS3 compliance.

Category 2 (Active, Standard Temperature): X28HC64SIZ-12 and X28HC64SZ-12 support standard or industrial temperature ranges with 120 ns access time and RoHS3 compliance.

Parameter Comparison

Engineering Selection Recommendations

All substitute parts maintain functional equivalence with the AT28C64-20SC through identical memory capacity, organization, interface, and package specifications. Selection among substitutes should be based on the following criteria:

For extended temperature applications (-40°C to 85°C): AT28C64B-15SU (Microchip, 150 ns access time) or X28HC64SIZ-12T1 (Renesas, 120 ns access time, Tape & Reel packaging) are appropriate selections. Both parts offer RoHS3 compliance and active product status.

For standard temperature applications (0°C to 70°C): X28HC64SZ-12 (Renesas, 120 ns access time, Tube packaging) maintains the original operating temperature range while providing improved access time and RoHS3 compliance.

For regulatory compliance: All active substitute parts are RoHS3 compliant, whereas the original AT28C64-20SC is non-compliant. New designs should incorporate one of the substitute parts to meet current environmental and regulatory requirements.

For performance improvement: All substitute parts offer equal or superior access times (120–150 ns) compared to the original 200 ns specification, providing design margin without functional compromise.

Frequently Asked Questions (FAQ)

Q: Can AT28C64B-15SU directly replace AT28C64-20SC in existing designs?

A: Yes. AT28C64B-15SU maintains identical memory capacity (64Kbit), organization (8K x 8), parallel interface, 28-SOIC package, and 4.5V to 5.5V supply voltage. The improved 150 ns access time is backward compatible with designs expecting 200 ns performance. Operating temperature range extends to -40°C to 85°C, supporting broader environmental conditions.

Q: What is the difference between X28HC64SIZ-12 and X28HC64SIZ-12T1?

A: Both parts are functionally identical with 64Kbit capacity, 120 ns access time, and -40°C to 85°C operating range. The primary difference is packaging: X28HC64SIZ-12 uses standard packaging (not specified), while X28HC64SIZ-12T1 is supplied in Tape & Reel format for automated assembly processes.

Q: Is X28HC64SZ-12 suitable for applications requiring extended temperature operation?

A: No. X28HC64SZ-12 operates across 0°C to 70°C, matching the original AT28C64-20SC temperature range. For extended temperature requirements (-40°C to 85°C), use AT28C64B-15SU or X28HC64SIZ-12T1.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All active substitute parts (AT28C64B-15SU, X28HC64SIZ-12, X28HC64SIZ-12T1, X28HC64SZ-12) are RoHS3 compliant. The original AT28C64-20SC is RoHS non-compliant.

Q: What is the impact of different write cycle times on system design?

A: Write cycle time affects the duration required to complete a single write operation. The original AT28C64-20SC specifies 1 ms write cycle time. Substitute parts specify 5–10 ms write cycle times. Systems must accommodate the longer write duration; however, this does not affect read operations or overall system functionality if write timing is not critical path.

Q: Can Renesas X28HC64 parts replace Microchip AT28C64 parts?

A: Yes. X28HC64SIZ-12, X28HC64SIZ-12T1, and X28HC64SZ-12 are functionally equivalent to AT28C64-20SC across all critical parameters: 64Kbit capacity, 8K x 8 organization, parallel interface, 28-SOIC package, and 4.5V to 5.5V supply voltage. Cross-manufacturer substitution is valid for this product category.