Renesas 72255LA15TFI

Overview

IDT72255LA15TFI from Integrated Device Technology, Inc. is a high-speed, 8,192 × 18-bit synchronous CMOS FIFO memory with independent read/write clocks, 15 ns clock cycle time, industrial temperature range (–40°C to +85°C), and 64-pin STQFP package. It supports both IDT Standard and First Word Fall Through (FWFT) timing modes and is used in telecom data buffering, video frame synchronization, and network packet queuing where deterministic latency and depth expansion are required.

For engineers reviewing the IDT72255LA15TFI datasheet, IDT72255LA15TFI pinout, IDT72255LA15TFI application, or IDT72255LA15TFI equivalent, key selection considerations include its fixed 8 ns access time, programmable almost-empty/full flags with dual default offsets (127/1023), auto power-down for standby current ≤20 mA, retransmit capability, and pin compatibility with IDT72275/72285 FIFOs.

Technical Context

This FIFO eliminates frequency dependency between RCLK and WCLK - no FS pin required - enabling fully asynchronous clock domains up to 66.7 MHz. Its architecture features separate input/output registers, RAM array, flag logic, and pointer control with master/partial reset and retransmit functions.

It delivers fixed first-word latency (3 RCLK cycles in FWFT mode; one RCLK+REN cycle in IDT Standard mode), triple-register-buffered OR output in FWFT mode, and double-register-buffered EF/FF outputs in IDT Standard mode. Flag behavior (EF/OR, FF/IR, HF, PAE, PAF) is mode-dependent and validated per Tables 1 and 2 in the datasheet.

Key Specifications

Pinout & Package

Package: 64-pin Slim Thin Quad Flat Pack (STQFP), order code TF, RoHS-compliant green variant available.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FIFO memory applications.

Compared with IDT72255LA15PF and IDT72265LA15TFI, the IDT72255LA15TFI provides optimal balance of industrial-grade reliability, compact STQFP footprint, and verified 66.7 MHz throughput - making it the preferred choice for space-constrained, high-reliability FIFO applications where 147 kbit depth suffices.

Availability

IDT72255LA15TFI is available at Aetrix Electronics and suitable for telecom infrastructure, industrial gateways, and video processing systems requiring stable component supply, long-lifecycle support, and RoHS-compliant green packaging.

Supply support for IDT72255LA15TFI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Integrated Device Technology, Inc. (IDT) is a fabless semiconductor company specializing in timing, memory interface, RF, and high-performance FIFO solutions for communications and computing markets.

IDT72255LA15TFI belongs to the SuperSync FIFO™ family - designed specifically for high-throughput, low-latency data buffering in multi-clock-domain systems such as networking equipment, broadcast video, and industrial automation controllers.

FAQ

What is the maximum operating frequency of the IDT72255LA15TFI?

The IDT72255LA15TFI supports a maximum clock cycle time of 15 ns, corresponding to a 66.7 MHz operational frequency for both RCLK and WCLK. This is guaranteed across the full industrial temperature range (–40°C to +85°C) with 5.0 V ±10% supply, per AC Electrical Characteristics Table on page 6 of the datasheet.

Does the IDT72255LA15TFI support independent read and write clock domains?

Yes, the IDT72255LA15TFI fully supports independent RCLK and WCLK domains with no frequency ratio restrictions - the FS pin has been removed from this generation. Both clocks may operate from DC to 66.7 MHz simultaneously, enabling robust asynchronous data bridging in mixed-clock systems.

How does the First Word Fall Through (FWFT) mode work on the IDT72255LA15TFI?

In FWFT mode - selected by holding FWFT/SI HIGH during Master Reset - the first word written to an empty IDT72255LA15TFI appears on Q0–Q17 after exactly three RCLK rising edges, without requiring REN assertion. Subsequent reads still require REN activation. This mode reduces initial latency for real-time streaming applications.

Can the programmable almost-empty and almost-full flags be customized on the IDT72255LA15TFI?

Yes, the IDT72255LA15TFI allows PAE and PAF thresholds to be set to either 127 or 1023 words via the LD pin at Master Reset, or reprogrammed dynamically using serial (via SI) or parallel (via D0–D17) methods. Default values are stored in dedicated offset registers and persist through Partial Reset.

Is the IDT72255LA15TFI pin-compatible with older IDT FIFOs?

Yes, the IDT72255LA15TFI is pin-compatible with IDT72275 and IDT72285 SuperSync FIFOs, allowing direct replacement in existing designs. Signal mapping, power pin locations, and flag pin functions match identically - simplifying migration while delivering improved latency and power efficiency.