Renesas Electronics 72255LA20TF8 Synchronous FIFO Logic IC

Part Overview

The Renesas Electronics 72255LA20TF8 is a Synchronous FIFO (First-In-First-Out) memory IC with 144K capacity (8K x 18 bits) in a 64-TQFP surface mount package. This component is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing system support and new designs. The part operates at 50MHz with a 12ns access time and is designed for uni-directional data flow applications requiring programmable flags and FWFT (First Word Fall Through) support.

Substiute Parts

72255LA20TF8

Renesas Electronics CorporationIn Stock: 75472255LA20TF8 Datasheet

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72255LA10TFG8

Renesas Electronics CorporationIn Stock: 92572255LA10TFG8 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 72255LA20TF8 is determined by strict equivalence in the following electrical and mechanical parameters:

Memory architecture must remain 144K (8K x 18 bits) to ensure data path compatibility. The synchronous FIFO function and uni-directional bus configuration are non-negotiable for circuit operation. The 64-TQFP (10x10mm) package ensures mechanical and electrical pin compatibility. Supply voltage range (4V to 5.5V) and operating temperature range (0°C to 70°C) must be maintained or exceeded. Programmable flags support, retransmit capability, and FWFT support are functional requirements that must be preserved.

The substitute part 72255LA10TFG8 meets all these criteria while offering performance improvements: increased data rate (100MHz vs. 50MHz) and reduced access time (8ns vs. 12ns). These enhancements are backward-compatible with applications designed for the original part.

Parameter Comparison

Engineering Selection Recommendations

The 72255LA10TFG8 is the direct substitute for the obsolete 72255LA20TF8. Both parts share identical memory architecture, functional capabilities, and physical packaging, ensuring drop-in compatibility at the circuit board level.

The substitute part offers two significant advantages: active product status ensures long-term availability and manufacturing support, and ROHS3 compliance satisfies modern environmental and regulatory requirements. The enhanced performance specifications (100MHz data rate and 8ns access time) provide operational headroom for existing designs without requiring circuit modifications.

For new designs or system refreshes, the 72255LA10TFG8 is the recommended selection. For legacy system maintenance where the original part is no longer available, the 72255LA10TFG8 provides functional equivalence with improved compliance posture.

Frequently Asked Questions (FAQ)

Q: Can the 72255LA10TFG8 directly replace the 72255LA20TF8 without circuit modifications?

A: Yes. Both parts are pin-compatible 64-TQFP packages with identical memory organization (8K x 18), electrical interfaces, and functional features. The substitute operates at higher performance levels, which is backward-compatible with applications designed for the original part.

Q: What is the significance of the performance difference (50MHz vs. 100MHz, 12ns vs. 8ns)?

A: The substitute part supports twice the data rate and has faster access time. These improvements do not create incompatibility; they expand the operational envelope. Existing circuits will function identically, with the substitute providing additional performance margin.

Q: Why is RoHS compliance important for this substitution?

A: ROHS3 compliance indicates the substitute part meets current environmental and regulatory standards for electronic components. The original part's non-compliance status may restrict its use in new designs or regulated applications. The substitute eliminates this constraint.

Q: Are the packaging and pinout identical between these parts?

A: Yes. Both parts use 64-TQFP (10x10mm) surface mount packages with identical pin assignments. Physical and electrical compatibility is guaranteed.

Q: What is the difference between the packaging designations (TF8 vs. TFG8)?

A: The suffix indicates packaging format. TF8 denotes standard packaging, while TFG8 indicates Tape & Reel (TR) packaging. This affects supply format but does not alter electrical or functional characteristics.