Renesas 72225LB15TFGI

Overview

IDT72225LB15TFGI from Integrated Device Technology is a 1,024 × 18-bit synchronous FIFO memory IC with dual-clock operation, 15 ns clock cycle time, industrial temperature range (–40°C to +85°C), and TQFP-64 package. It provides programmable Almost-Empty/Almost-Full flags, Half-Full flag, and depth/width expansion capability for buffering in LAN controllers, interprocessor communication, and optical disk interfaces.

For engineers reviewing the IDT72225LB15TFGI datasheet, IDT72225LB15TFGI pinout, IDT72225LB15TFGI application, or IDT72225LB15TFGI equivalent, key selection criteria include its 1,024-word depth, 18-bit bus width, asynchronous read/write clock support, programmable flag offsets, and industrial-grade reliability in high-speed data buffering systems.

Technical Context

This FIFO implements a dual-port zero fall-through time architecture with independent read and write pointer logic, offset register programming via LD/WEN/RCLK/REN control, and synchronized status flags (EF/FF) tied to respective clocks. Its submicron CMOS process enables low-power active current (≤60 mA) and fast access (≤10 ns).

The device supports single-clock (RCLK = WCLK) or dual-clock operation, with configurable expansion via WXI/WXO and RXI/RXO pins. Programmable Almost-Empty and Almost-Full flags default to 127-word offsets, and the Half-Full flag operates in single-device mode without expansion logic overhead.

Key Specifications

Pinout & Package

Package: 64-lead thin quad flatpack (TQFP), order code PP64-1, body size 10 mm × 10 mm, lead pitch 0.5 mm, 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 72225LB15JG and 72225L15TFGI, IDT72225LB15TFGI uniquely combines industrial temperature qualification, TQFP-64 compactness, and full feature set-including HF flag and daisy-chain expansion-making it the only option for ruggedized, space-constrained, multi-device buffering systems.

Availability

IDT72225LB15TFGI is available at Aetrix Electronics and suitable for LAN controllers, interprocessor communication links, and optical disk interfaces requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for IDT72225LB15TFGI 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 high-performance interconnect solutions.

IDT72225LB15TFGI belongs to the SyncFIFO™ family-designed specifically for deterministic, low-latency data buffering in high-speed digital systems where clock domain crossing and burst absorption are critical.

FAQ

What is the memory organization and maximum operating frequency of the IDT72225LB15TFGI?

IDT72225LB15TFGI features a 1,024 × 18-bit synchronous FIFO array, providing 18.4 kbit of buffer memory. Its 15 ns clock cycle time supports a maximum operating frequency of 66.7 MHz for both read and write clocks, verified under industrial temperature conditions (–40°C to +85°C) and 5 V ±10% supply.

Does the IDT72225LB15TFGI support dual-clock operation, and how are read/write pointers managed?

Yes, IDT72225LB15TFGI fully supports asynchronous dual-clock operation: WCLK controls write pointer advancement, and RCLK controls read pointer advancement. Pointers operate independently with no shared logic-enabling robust clock domain crossing. Status flags EF and FF are synchronized to their respective clocks, eliminating metastability risks in cross-domain signaling.

How does the Half-Full (HF) flag function in the IDT72225LB15TFGI, and when is it active?

In single-device configuration (FL = GND, WXI = RXI = GND), the IDT72225LB15TFGI's WXO/HF pin functions as a Half-Full flag. It asserts LOW when ≥512 words are stored (i.e., ≥50% of 1,024 depth) and remains LOW until the word count drops to ≤511. HF is updated on the WCLK rising edge and reset on the RCLK rising edge, making it asynchronous but deterministic for scheduling logic.

What are the default offset values for the Programmable Almost-Empty and Almost-Full flags in the IDT72225LB15TFGI?

IDT72225LB15TFGI defaults to 127-word offsets for both PAE and PAF flags after reset-meaning PAE goes LOW when 127 words remain before empty, and PAF goes LOW when 127 words remain before full. These values are stored in dedicated 12-bit offset registers and can be reprogrammed via LD/WEN/RCLK sequences per the datasheet timing diagrams.

Can multiple IDT72225LB15TFGI devices be cascaded to increase total FIFO depth, and what pins enable this?

Yes, IDT72225LB15TFGI supports depth expansion via daisy-chaining. The WXO (Write Expansion Out) and RXO (Read Expansion Out) pins of one device connect to WXI (Write Expansion In) and RXI (Read Expansion In) of the next. FL must be grounded on the first device and pulled HIGH on all subsequent devices to configure proper pointer sequencing across the chain.