Equivalent & Substitute Parts for 7140LA55JI

Part Overview

The 7140LA55JI 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 supports parallel data interfaces across a 4.5V to 5.5V supply range. The product is classified as obsolete, making identification of compatible substitute parts essential for system maintenance, repair, and legacy equipment support.

Substiute Parts

7140LA55JI

Renesas Electronics CorporationIn Stock: 7777140LA55JI Datasheet

Current PartRFQ

7140LA20JG

Renesas Electronics CorporationIn Stock: 7517140LA20JG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the 7140LA55JI is determined by strict equivalence across the following critical 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)
• Surface mount mounting type

The 7140LA20JG qualifies as a direct substitute based on identical memory specifications, package type, and voltage requirements. Access time and write cycle time are faster (20 ns versus 55 ns), which maintains backward compatibility in timing-critical applications. Operating temperature range differs; the substitute supports 0°C ~ 70°C versus the original -40°C ~ 85°C specification.

Parameter Comparison

Engineering Selection Recommendations

The 7140LA20JG is a qualified substitute for the 7140LA55JI based on functional equivalence and package compatibility. The substitute part offers improved performance characteristics with faster access and write cycle times (20 ns versus 55 ns), which provides enhanced timing margins in legacy system designs.

The 7140LA20JG carries ROHS3 compliance status, whereas the original part is non-compliant. This distinction is relevant for new procurement and system redesigns subject to RoHS regulations.

Operating temperature range differs between the parts. The original 7140LA55JI supports -40°C ~ 85°C, while the substitute 7140LA20JG operates within 0°C ~ 70°C. Applications requiring extended low-temperature operation below 0°C must account for this specification difference.

Both parts share identical supply voltage requirements (4.5V ~ 5.5V), package footprint (52-PLCC), and memory organization (1K x 8), ensuring direct pin-compatible replacement in circuit board layouts.

Frequently Asked Questions (FAQ)

Q: Can the 7140LA20JG replace the 7140LA55JI in existing designs?

A: Yes. The 7140LA20JG is pin-compatible and functionally equivalent. Both parts use the 52-PLCC package, support identical memory capacity and organization, and operate within the same supply voltage range. The substitute offers faster access times, which maintains backward compatibility.

Q: What is the primary difference between these two parts?

A: Access time and write cycle time differ. The 7140LA55JI operates at 55 ns, while the 7140LA20JG operates at 20 ns. The substitute is faster and provides improved timing performance. Operating temperature range also differs: the original supports -40°C ~ 85°C, while the substitute supports 0°C ~ 70°C.

Q: Are there package or pinout differences?

A: No. Both parts use the 52-PLCC (J-Lead) package with identical footprint dimensions (19.13x19.13 mm) and pinout configuration. Direct board-level substitution is possible without layout modifications.

Q: Does RoHS compliance affect substitution?

A: The 7140LA20JG is ROHS3 compliant, while the 7140LA55JI is non-compliant. For applications subject to RoHS regulations, the substitute part meets current environmental standards. For legacy systems without RoHS requirements, both parts are functionally interchangeable.

Q: What supply voltage do these parts require?

A: Both the 7140LA55JI and 7140LA20JG operate within a 4.5V ~ 5.5V supply range. No voltage adjustment is required when substituting between these parts.

Q: Are there temperature-related constraints for substitution?

A: The original part supports -40°C ~ 85°C operation, while the substitute supports 0°C ~ 70°C. Applications requiring operation below 0°C or above 70°C must use the original 7140LA55JI or identify alternative parts with extended temperature ratings.