Renesas 72225LB15PFGI

Overview

IDT72225LB15PFGI from Integrated Device Technology (IDT) is a high-speed, low-power 1,024 × 18-bit synchronous FIFO memory with dual-clock operation, 10 ns read/write cycle time, and industrial temperature support (–40°C to +85°C). It features programmable Almost-Empty/Almost-Full flags, Half-Full flag, and depth/width expandability-used in optical disk controllers, LAN interfaces, and interprocessor communication buffers.

For engineers reviewing the IDT72225LB15PFGI datasheet, IDT72225LB15PFGI pinout, IDT72225LB15PFGI application, or IDT72225LB15PFGI equivalent, key selection criteria include its 1,024-word depth, 18-bit bus width, 10 ns timing, TQFP-64 package, and dual-clock asynchronous flag behavior-critical for deterministic data buffering in mixed-clock domain systems.

Technical Context

This device implements a dual-port zero fall-through time architecture with independent read/write pointers, enabling concurrent access without latency penalty. Its flag logic supports both synchronous (EF/FF) and asynchronous (PAE/PAF/HF) status reporting, with offset registers configurable via LD/WEN/RCLK sequences.

The FIFO uses submicron CMOS technology and supports three operational modes: single-device, width expansion (parallel data bus), and daisy-chain depth expansion using WXI/WXO and RXI/RXO pins. Reset initialization sets pointers to zero and loads default offsets (127 for PAE/PAF), ensuring deterministic startup behavior.

Key Specifications

Pinout & Package

Package: 64-lead thin quad flatpack (TQFP), PN64-1 order code, lead finish SnPb (end-of-life as of June 2018).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 72225L15PF and 72225LB15TF, the IDT72225LB15PFGI offers identical timing and logic behavior but uses SnPb finish in TQFP-64-making it suitable for legacy industrial assemblies where Pb-free rework is not feasible and EOL procurement windows permit.

Availability

IDT72225LB15PFGI is available at Aetrix Electronics and suitable for optical disk controllers, industrial Ethernet interfaces, multi-processor communication links, and legacy bus bridge designs requiring stable component supply and long-term industrial temperature support.

Supply support for IDT72225LB15PFGI 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 (IDT), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor signal conditioning ICs.

The IDT72225LB15PFGI belongs to the SyncFIFO™ family-designed specifically for deterministic, low-latency data buffering in mixed-clock-domain systems such as storage controllers, networking gear, and real-time embedded subsystems.

FAQ

What is the memory organization of the IDT72225LB15PFGI?

The IDT72225LB15PFGI implements a 1,024 × 18-bit synchronous FIFO array, providing 18,432 bits of buffer storage. This configuration supports 18-bit parallel data paths and is optimized for applications requiring moderate-depth, high-speed buffering between asynchronous clock domains. The IDT72225LB15PFGI's fixed depth eliminates address management overhead compared to SRAM-based solutions.

Does the IDT72225LB15PFGI support both single-clock and dual-clock operation?

Yes, the IDT72225LB15PFGI supports both configurations: WCLK and RCLK can be tied together for single-clock operation, or run independently for true dual-clock asynchronous buffering. In dual-clock mode, EF and FF flags are synchronized to their respective clocks, while PAE, PAF, and HF operate asynchronously-enabling robust flow control across clock boundaries. The IDT72225LB15PFGI's architecture ensures deterministic behavior in either mode.

What are the default values for the programmable Almost-Empty and Almost-Full offsets in the IDT72225LB15PFGI?

The IDT72225LB15PFGI defaults to an offset of 127 words for both the Almost-Empty (PAE) and Almost-Full (PAF) flags after reset. This means PAE asserts when 127 words remain before empty, and PAF asserts when 127 words remain before full-providing a 12.5% buffer margin. These offsets are stored in 12-bit registers and can be reprogrammed via the LD/WEN sequence using D0–D11 inputs.

Is the IDT72225LB15PFGI compatible with 3.3 V logic systems?

No-the IDT72225LB15PFGI is a 5 V-only device with VIH = 2.0 V minimum and VIL = 0.8 V maximum, designed for TTL/CMOS 5 V logic families. It is not 3.3 V tolerant: applying 3.3 V signals to inputs may cause unreliable operation, and driving 5 V outputs into 3.3 V receivers risks damage. Level-shifting circuitry is required for interoperability with 3.3 V systems. The IDT72225LB15PFGI must be powered with 4.5–5.5 V.

How does the Half-Full flag (WXO/HF) function in single-device mode for the IDT72225LB15PFGI?

In single-device mode (FL, WXI, RXI grounded), the WXO/HF pin functions exclusively as a Half-Full flag: it goes LOW when exactly 512 words (half of 1,024) are stored, and remains LOW until the word count drops to ≤511. HF is updated on the rising edge of WCLK and reset on the rising edge of RCLK. This provides precise midpoint signaling for balanced read/write scheduling-unlike EF/FF, HF is asynchronous and does not gate data transfers. The IDT72225LB15PFGI's HF behavior is deterministic and repeatable across temperature and voltage.