Renesas 72235LB15TFGI

Overview

IDT72235LB15TFGI from Integrated Device Technology is a high-speed 2,048 × 18-bit synchronous FIFO memory with dual-clock operation, 10 ns read/write cycle time, programmable Almost-Empty/Almost-Full flags, and Half-Full flag capability - used in optical disk controllers, LAN interfaces, and interprocessor communication buffers.

For engineers reviewing the IDT72235LB15TFGI datasheet, IDT72235LB15TFGI pinout, IDT72235LB15TFGI application, or IDT72235LB15TFGI equivalent, key selection considerations include its 2,048-word depth, 18-bit bus width, industrial temperature range (–40°C to +85°C), TQFP-64 package, and support for asynchronous or coincident clock domains.

Technical Context

This device implements a dual-port zero fall-through time architecture with independent read/write pointer logic, offset-register-controlled programmable status flags, and daisy-chain expansion via WXI/WXO and RXI/RXO pins. It supports both single-clock (RCLK = WCLK) and dual-clock (asynchronous RCLK/WCLK) operation with skew timing constraints (tSKEW1/tSKEW2 ≥ 5 ns).

The FIFO uses high-performance submicron CMOS technology, features output enable (OE) for three-state control, and includes dedicated reset (RS) that initializes pointers and default flag offsets (127 for PAE/PAF). Its dual-purpose WXO/HF pin serves as Half-Full indicator in single-device mode or write-expansion pulse in depth expansion.

Key Specifications

Pinout & Package

Package: 64-pin Thin Quad Flatpack (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 72235L15TFGI, IDT72235LB15TFGI adds industrial temperature qualification and enhanced reliability testing; compared with 72235LB25TFGI, it delivers 66.7 MHz operation at same power envelope - making it optimal for new industrial data-path designs requiring both speed and ruggedness.

Availability

IDT72235LB15TFGI is available at Aetrix Electronics and suitable for optical disk controllers, LAN interface modules, and interprocessor communication systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for IDT72235LB15TFGI 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, and high-performance interconnect solutions.

IDT72235LB15TFGI belongs to the SyncFIFO™ family designed specifically for deterministic, low-latency data buffering in mixed-clock-domain systems - targeting industrial, telecom, and storage applications demanding robust synchronization and expandable memory depth.

FAQ

What is the memory organization of IDT72235LB15TFGI?

IDT72235LB15TFGI provides a 2,048 × 18-bit synchronous FIFO configuration - meaning it stores up to 2,048 words, each 18 bits wide. This organization is fixed and cannot be reconfigured. The device uses dual-port RAM architecture with independent read and write pointers, enabling concurrent access without contention. Its depth is confirmed in the datasheet's feature list and functional block diagram.

Does IDT72235LB15TFGI support both single-clock and dual-clock operation?

Yes, IDT72235LB15TFGI supports both modes: RCLK and WCLK can be tied together for single-clock operation, or run independently for true dual-clock (asynchronous) buffering. The datasheet specifies minimum skew times (tSKEW1/tSKEW2 ≥ 5 ns) to ensure reliable flag updates across clock domains. This flexibility makes IDT72235LB15TFGI suitable for bridging disparate timing domains in complex SoC or FPGA-based systems.

What is the default offset value for the Programmable Almost-Empty flag in IDT72235LB15TFGI?

The default PAE offset for IDT72235LB15TFGI is 127 words from empty, as specified in the Pin Description table and Signal Descriptions section. This value is loaded into the Empty Offset register upon reset and determines when the PAE flag asserts LOW. It can be reprogrammed via the LD/WEN sequence using D0–D11 inputs, allowing system-level tuning of buffer threshold behavior in IDT72235LB15TFGI implementations.

Is IDT72235LB15TFGI pin-compatible with other members of the IDT722xxLB family?

IDT72235LB15TFGI shares identical pinout and package (64-pin STQFP) with all variants in the IDT722xxLB family, including IDT72205LB, IDT72215LB, IDT72225LB, and IDT72245LB. However, memory depth differs per part number - so while physical replacement is possible, functional compatibility requires verifying depth requirements. The datasheet confirms uniform pin assignments across the series in the PIN CONFIGURATIONS section.

What does the "LB" suffix signify in IDT72235LB15TFGI?

The "LB" suffix in IDT72235LB15TFGI denotes the industrial temperature grade and lead-free (green) packaging option. "L" indicates industrial temperature range (–40°C to +85°C), and "B" signifies compliance with RoHS and halogen-free material requirements. This distinguishes it from commercial-grade "L" parts and older SnPb-finished versions, confirming IDT72235LB15TFGI is qualified for harsh operating environments and modern environmental standards.