Renesas 72225LB10PFG8

Overview

IDT72225LB10PFG8 from Integrated Device Technology is a 1,024 × 18-bit synchronous FIFO memory IC with dual-clock operation, 10 ns read/write cycle time, and industrial temperature range (–40°C to +85°C). It features programmable Almost-Empty/Almost-Full flags, Half-Full flag, and depth/width expandability-used in LAN controllers, optical disk interfaces, and interprocessor data buffering where deterministic latency and clock domain bridging are required.

For engineers reviewing the IDT72225LB10PFG8 datasheet, IDT72225LB10PFG8 pinout, IDT72225LB10PFG8 application, or IDT72225LB10PFG8 equivalent, key selection criteria include its 18-bit bidirectional data width, TQFP-64 package, 5 V supply compatibility, asynchronous dual-clock support, and configurable status flag offsets for real-time buffer monitoring.

Technical Context

This FIFO implements a dual-port zero fall-through time architecture with independent read/write pointers, offset-controlled programmable flags (PAE/PAF), and synchronous RAM array. Its functional block includes input/output registers, expansion logic, and flag generation circuitry synchronized to respective clocks (WCLK/RCLK).

The device supports single-clock (coincident RCLK/WCLK) or dual-clock (asynchronous RCLK/WCLK) operation with skew timing constraints (tSKEW1/tSKEW2 ≥ 5 ns). Flag outputs (EF, FF, PAE, PAF, HF) are edge-triggered and updated on rising edges of their associated clocks-enabling precise buffer state tracking in mixed-domain systems.

Key Specifications

Pinout & Package

Package: 64-lead thin quad flatpack (TQFP), lead finish SnPb (end-of-life as of June 2018), body size 10 mm × 10 mm, 0.5 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 72225L10PFG and 72225LB15PFG8, IDT72225LB10PFG8 delivers the highest speed grade in the same footprint-making it optimal for bandwidth-constrained interfaces like legacy PCI-X or high-speed serial link buffers where latency directly impacts system jitter.

Availability

IDT72225LB10PFG8 is available at Aetrix Electronics and suitable for LAN controllers, optical storage interfaces, interprocessor communication links, and real-time motion control systems requiring stable component supply across extended product lifecycles.

Supply support for IDT72225LB10PFG8 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.

IDT72225LB10PFG8 belongs to the SyncFIFO™ family-designed specifically for deterministic, low-latency data buffering in multi-clock-domain systems such as networking equipment, storage controllers, and industrial automation platforms.

FAQ

What is the memory organization of the IDT72225LB10PFG8?

The IDT72225LB10PFG8 implements a 1,024 × 18-bit synchronous FIFO architecture-providing 18.4 kbit of first-in-first-out buffering with independent read and write address pointers. This configuration supports 18-bit parallel data paths and is optimized for applications requiring precise depth control and deterministic latency, such as protocol bridging and burst-mode data capture. The IDT72225LB10PFG8 does not support random access or byte-level addressing.

Does the IDT72225LB10PFG8 support both single-clock and dual-clock operation?

Yes, the IDT72225LB10PFG8 supports both modes: RCLK and WCLK can be tied together for single-clock operation, or run asynchronously for dual-clock domain bridging. In dual-clock mode, timing skew constraints (tSKEW1 ≥ 5 ns, tSKEW2 ≥ 5 ns) must be met to guarantee correct FF/EF flag transitions. The IDT72225LB10PFG8's flag logic is clock-domain-specific-EF updates on RCLK edges, FF updates on WCLK edges-ensuring accurate status reporting regardless of clock relationship.

What are the default values for the programmable Almost-Empty and Almost-Full offsets in the IDT72225LB10PFG8?

The IDT72225LB10PFG8 defaults to 127-word offsets for both PAE and PAF after reset-meaning the Almost-Empty flag asserts when 127 words remain before empty, and the Almost-Full flag asserts when 127 words remain before full. These values are stored in 12-bit offset registers and can be reprogrammed via the LD/WEN/RCLK sequence using D0–D11. The IDT72225LB10PFG8's default aligns with its 1,024-word depth to provide ~12.5% buffer margin for flow-control decisions.

Is the IDT72225LB10PFG8 compatible with 3.3 V logic systems?

No, the IDT72225LB10PFG8 is a 5 V-only device with VIH = 2.0 V min and VIL = 0.8 V max-designed for TTL/CMOS-5V interfacing. It lacks 3.3 V I/O tolerance and requires level translation when connecting to 3.3 V microcontrollers or FPGAs. Operating outside its 4.5–5.5 V VCC range may cause functional failure or accelerated wear. The IDT72225LB10PFG8 does not support mixed-voltage operation or internal voltage regulation.

How is depth expansion implemented using the IDT72225LB10PFG8 in a daisy-chain configuration?

Depth expansion uses WXO/HF and RXO outputs driving WXI and RXI inputs of the next device. FL is grounded on the first device and pulled HIGH on all subsequent devices. Each device increments the effective depth by 1,024 words, with WXO pulsing on last-write and RXO pulsing on last-read to coordinate pointer advancement across the chain. The IDT72225LB10PFG8 maintains identical timing and flag behavior in expanded configurations-no external arbitration logic is needed, and all devices share common WCLK/RCLK nets.