Renesas Electronics 71421LA55PF SRAM Equivalent & Substitute Parts

Part Overview

The Renesas Electronics 71421LA55PF is a 16Kbit dual-port asynchronous SRAM memory IC in 64-TQFP surface mount packaging. This component is classified as obsolete, indicating discontinued production and limited availability. The part operates with a 55 ns access time and write cycle time, functioning within a 4.5V to 5.5V supply voltage range across an operating temperature of 0°C to 70°C. Due to its obsolete status and non-RoHS3 compliance, identifying functionally equivalent active production alternatives is essential for new designs and ongoing system support.

Substiute Parts

71421LA55PF

Renesas Electronics CorporationIn Stock: 76971421LA55PF Datasheet

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71421LA20PFG

Renesas Electronics CorporationIn Stock: 100671421LA20PFG Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the 71421LA55PF is determined by strict equivalence across the following critical parameters:

• Memory capacity and organization (16Kbit, 2K x 8 configuration)
• Dual-port asynchronous SRAM architecture
• Parallel memory interface
• Pin-compatible 64-TQFP (14x14) package
• Identical voltage supply range (4.5V ~ 5.5V)
• Matching operating temperature range (0°C ~ 70°C)
• Equivalent or faster access and write cycle times

The 71421LA20PFG meets all substitution criteria. This part maintains identical memory capacity, organization, interface type, and packaging while offering improved performance specifications (20 ns access and write cycle times versus 55 ns). The faster timing characteristics ensure backward compatibility in applications where the original part's timing margins are acceptable.

Parameter Comparison

Engineering Selection Recommendations

The 71421LA20PFG is the direct functional equivalent for the obsolete 71421LA55PF. Selection of this substitute is justified on the following engineering grounds:

Product Status: The 71421LA20PFG maintains active production status, ensuring long-term availability and supply chain continuity compared to the discontinued 71421LA55PF.

Compliance Posture: The substitute achieves RoHS3 compliance, meeting current regulatory requirements for electronic components in regulated markets. The original part's non-compliant status presents procurement and documentation challenges for new system designs.

Performance Characteristics: The 20 ns access and write cycle times of the substitute represent a performance improvement over the original 55 ns specification. This faster timing is fully backward compatible with designs originally specified for the 71421LA55PF, as timing-critical applications will experience reduced latency without functional degradation.

Electrical and Mechanical Compatibility: Identical voltage supply range, operating temperature range, package geometry, and pin configuration ensure direct substitution without circuit redesign or PCB modification.

Frequently Asked Questions (FAQ)

Q: Can the 71421LA20PFG directly replace the 71421LA55PF without PCB modifications?

A: Yes. Both parts share identical pin configurations, package dimensions (64-TQFP 14x14), voltage supply requirements (4.5V ~ 5.5V), and operating temperature ranges (0°C ~ 70°C). No PCB layout changes are required.

Q: What is the primary advantage of substituting to the 71421LA20PFG?

A: The substitute offers three key advantages: active production status ensuring availability, RoHS3 compliance for regulatory alignment, and improved access time (20 ns versus 55 ns) providing performance headroom in timing-sensitive applications.

Q: Are there any timing compatibility concerns when using the faster 71421LA20PFG?

A: No. The faster access and write cycle times of the substitute are fully compatible with designs originally specified for the 55 ns part. Faster memory components do not introduce timing violations in systems designed for slower components.

Q: Do both parts require identical handling and storage conditions?

A: Yes. Both parts carry MSL 3 (168 Hours) moisture sensitivity ratings, requiring equivalent moisture control, storage temperature, and humidity management during handling and assembly.

Q: What is the memory organization of these parts?

A: Both the 71421LA55PF and 71421LA20PFG are organized as 2K x 8 (2048 words by 8 bits), providing 16Kbit total capacity with parallel memory interface architecture.