Equivalent & Substitute Parts for 7140LA55J8

Part Overview

The 7140LA55J8 is an 8Kbit dual-port asynchronous SRAM manufactured by Renesas Electronics Corporation in a 52-PLCC package. This memory IC operates with a 55 ns access time and is designed for parallel interface applications requiring volatile memory storage. The part is classified as obsolete, making identification of compatible substitutes essential for system maintenance, repair, and legacy equipment support.

Substiute Parts

7140LA55J8

Renesas Electronics CorporationIn Stock: 9207140LA55J8 Datasheet

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7140LA20JG8

Renesas Electronics CorporationIn Stock: 19937140LA20JG8 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 7140LA55J8 is determined by strict equivalence in the following parameters:

• Memory capacity (8Kbit) and organization (1K x 8)
• Dual-port asynchronous SRAM technology
• Parallel interface configuration
• 52-PLCC package footprint and pinout compatibility
• Supply voltage range (4.5V ~ 5.5V)
• Operating temperature range (0°C ~ 70°C)

The 7140LA20JG8 qualifies as a direct substitute because it maintains identical memory specifications, package geometry, and electrical operating conditions. The primary difference is improved access time performance (20 ns versus 55 ns), which represents a performance upgrade rather than a functional incompatibility.

Parameter Comparison

Engineering Selection Recommendations

The 7140LA20JG8 is the qualified substitute for the 7140LA55J8 based on the following factors:

• Functional equivalence in memory capacity, organization, and interface type
• Identical package footprint and pinout compatibility
• Matching electrical specifications and operating ranges
• Active product status with confirmed availability
• ROHS3 compliance, addressing regulatory requirements that the original part does not meet
• Improved access time performance (20 ns) provides timing margin for legacy system integration

The substitute part maintains backward compatibility while offering enhanced performance characteristics and current manufacturing compliance status.

Frequently Asked Questions (FAQ)

Q: Can the 7140LA20JG8 be used as a direct replacement for the 7140LA55J8 in existing circuit boards?

A: Yes. Both parts share identical 52-PLCC package geometry, pinout configuration, and electrical operating parameters. The substitute part is functionally compatible and can be soldered into the same PCB footprint without modification.

Q: What is the significance of the access time difference between 55 ns and 20 ns?

A: The 7140LA20JG8 provides faster memory access, which represents a performance upgrade. Systems designed for 55 ns operation will function correctly with the faster 20 ns part. No timing violations occur when substituting a faster device into a circuit designed for slower operation.

Q: Are there packaging differences between these parts?

A: Both parts use the 52-PLCC (J-Lead) surface mount package with identical dimensions (19.13 x 19.13 mm). The 7140LA20JG8 is supplied in Tape & Reel format, while the 7140LA55J8 packaging format is not specified. This does not affect functional compatibility.

Q: Why is the 7140LA55J8 classified as obsolete?

A: The part has reached end-of-life status from the manufacturer. The 7140LA20JG8 represents the active product line continuation with equivalent functionality and improved specifications.

Q: Does the RoHS compliance difference affect substitution?

A: The 7140LA20JG8 meets ROHS3 compliance requirements, while the 7140LA55J8 does not. For applications subject to RoHS regulations, the substitute part is the compliant choice. For legacy systems without regulatory requirements, both parts are electrically compatible.