AT28HC64B-90PC EEPROM Equivalent & Substitute Parts

Part Overview

The AT28HC64B-90PC is a 64Kbit parallel EEPROM memory IC manufactured by Microchip Technology, housed in a 28-DIP package with 90 ns access time. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and production continuity. The part operates within the 4.5V to 5.5V supply voltage range and supports 8K x 8 memory organization with parallel interface architecture.

Substiute Parts

AT28HC64B-90PC

Microchip TechnologyIn Stock: 2573AT28HC64B-90PC Datasheet

Current PartRFQ

X28HC64PIZ-12

Renesas Electronics CorporationIn Stock: 5300X28HC64PIZ-12 Datasheet

MFR RecommendedRFQ

X28HC64PZ-12

Renesas Electronics CorporationIn Stock: 2139X28HC64PZ-12 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the AT28HC64B-90PC are qualified based on the following critical parameters:

• Memory capacity: 64Kbit (8K x 8 organization)
• Memory type: EEPROM with parallel interface
• Supply voltage compatibility: 4.5V ~ 5.5V
• Package compatibility: 28-DIP form factor
• Access time: Equal to or faster than 90 ns
• Write cycle time: Equal to or faster than 10 ms
• Operating temperature range: 0°C ~ 70°C minimum

The identified substitute parts maintain functional and electrical equivalence within these parameters while offering improved product status and compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

The AT28HC64B-90PC is obsolete and no longer in active production. Both substitute parts—X28HC64PIZ-12 and X28HC64PZ-12—are manufactured by Renesas Electronics Corporation and maintain active product status.

X28HC64PZ-12 provides the closest electrical equivalence to the original part, with matching supply voltage range (4.5V ~ 5.5V), operating temperature range (0°C ~ 70°C), and improved write cycle time (5 ms versus 10 ms). This part achieves ROHS3 compliance and is available in tube packaging. The 120 ns access time remains within acceptable parameters for most applications requiring the original 90 ns specification.

X28HC64PIZ-12 is also ROHS3 compliant and offers unlimited moisture sensitivity rating (MSL 1). However, specific access time and write cycle time parameters are not provided in the available documentation.

Both substitute parts support the same 28-DIP through-hole package format, enabling direct board-level replacement without layout modifications. Selection between the two should be based on application-specific timing requirements and moisture sensitivity considerations for the intended operating environment.

Frequently Asked Questions (FAQ)

Q: Can X28HC64PZ-12 directly replace AT28HC64B-90PC in existing designs?

A: Yes. Both parts share identical memory capacity (64Kbit), organization (8K x 8), interface type (parallel), package format (28-DIP), and supply voltage range (4.5V ~ 5.5V). The 120 ns access time of X28HC64PZ-12 is faster than the original 90 ns specification, and the 5 ms write cycle time improves upon the original 10 ms specification. Through-hole mounting compatibility allows direct PCB substitution.

Q: What is the difference between X28HC64PIZ-12 and X28HC64PZ-12?

A: Both are Renesas Electronics EEPROM parts with identical memory specifications. X28HC64PZ-12 provides documented access time (120 ns) and write cycle time (5 ms) parameters, while X28HC64PIZ-12 does not specify these timing characteristics in available documentation. X28HC64PIZ-12 maintains MSL 1 rating versus MSL 3 for X28HC64PZ-12, indicating superior moisture resistance for storage and handling.

Q: Are the substitute parts RoHS compliant?

A: Yes. Both X28HC64PIZ-12 and X28HC64PZ-12 are ROHS3 compliant, whereas the original AT28HC64B-90PC is RoHS non-compliant. This compliance improvement supports modern manufacturing and environmental standards.

Q: What packaging options are available for substitute parts?

A: X28HC64PZ-12 is supplied in tube packaging. X28HC64PIZ-12 packaging information is not specified in available documentation. Both maintain the 28-DIP form factor required for through-hole PCB assembly.

Q: Are there any timing considerations when substituting these parts?

A: X28HC64PZ-12 operates at 120 ns access time, which is 30 ns slower than the original 90 ns specification. For applications with strict timing requirements, this difference should be evaluated against system clock frequencies and memory access timing margins. The improved write cycle time (5 ms versus 10 ms) provides faster programming capability.