Renesas 72V235L15TFGI

Overview

72V235L15TFGI from Integrated Device Technology (IDT) is a 3.3 V, 2,048 × 18-bit synchronous FIFO memory IC with dual-clock operation, 15 ns clock cycle time, and industrial temperature range (–40°C to +85°C). It supports IDT Standard and First Word Fall-Through (FWFT) timing modes, programmable Almost-Empty/Almost-Full flags, and depth/width expansion via daisy-chain. Used in LAN controllers, interprocessor communication, and optical disk interfaces.

For engineers reviewing the 72V235L15TFGI datasheet, 72V235L15TFGI pinout, 72V235L15TFGI application, or 72V235L15TFGI equivalent, key selection criteria include dual-clock synchronization capability, 18-bit bus width, 15 ns timing grade, industrial-grade reliability, and configurable flag behavior (synchronous/asynchronous, buffered depth).

Technical Context

This FIFO implements a high-speed submicron CMOS architecture with independent read/write pointer logic, offset-programmable flags, and configurable register buffering (single/double/triple) for EF/FF signals. It supports both asynchronous and coincident clock domains, with programmable flag timing (synchronous or asynchronous PAE/PAF) selected at reset via FL/RXI/WXI pins.

The device features two fixed status flags (EF/OR and FF/IR), two programmable flags (PAE and PAF), and a Half-Full (HF) flag. Flag behavior differs between IDT Standard and FWFT modes - e.g., in FWFT mode, OR goes LOW after first write and remains active until last word is read, enabling zero-latency output readiness.

Key Specifications

Pinout & Package

72V235L15TFGI is housed in a 64-lead thin quad flatpack (TQFP), designated STQFP per IDT ordering code TF. Pin layout follows JEDEC MO-220 standard with 0.5 mm pitch and exposed thermal pad (not electrically connected).

Key Features

Applications

Equivalent & Alternatives

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

Compared with 72V235L15TFGI, the 72V235L15PFI offers identical functionality in a legacy PQFP package with higher thermal resistance, while 72V233L15TFGI halves memory depth without altering interface or timing - making both alternatives viable only when depth, package, or thermal requirements differ.

Availability

72V235L15TFGI is available at Aetrix Electronics and suitable for LAN controllers, interprocessor communication links, and optical disk interfaces requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for 72V235L15TFGI 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) was a fabless semiconductor company specializing in timing, memory interface, RF, and power management ICs before its acquisition by Renesas Electronics in 2019. Known for high-performance FIFOs, clock generators, and serial switch fabrics.

The IDT72V2xx family was designed specifically for high-speed, low-power data buffering in mixed-clock-domain systems - targeting networking, storage, and real-time embedded applications where deterministic latency and robust flag signaling are critical.

FAQ

What is the memory organization and speed grade of 72V235L15TFGI?

72V235L15TFGI is a 2,048 × 18-bit synchronous FIFO with a 15 ns clock cycle time, supporting up to 66.7 MHz operation. Its organization provides 36,864 bits of buffer memory, optimized for 18-bit parallel data paths in industrial and networking applications. The "L15" suffix explicitly denotes the 15 ns speed grade.

Does 72V235L15TFGI support both single-clock and dual-clock operation?

Yes, 72V235L15TFGI supports both configurations: RCLK and WCLK can be tied together for single-clock operation, or run asynchronously for true dual-clock domain bridging. The device guarantees timing integrity with ≥6 ns clock skew tolerance (tSKEW1), and all AC parameters are specified under both conditions.

How is the First Word Fall-Through (FWFT) mode enabled on 72V235L15TFGI?

FWFT mode is selected during power-on reset by asserting specific logic levels on FL, RXI, and WXI pins per Table 3 in the datasheet - for example, FL=0, RXI=0, WXI=1 configures FWFT with triple-buffered OR and double-buffered IR. This configuration is latched at reset and remains active until next reset.

What are the default programmable flag offset values for 72V235L15TFGI?

For 72V235L15TFGI, the default Almost-Empty and Almost-Full offsets are both 127 words from empty/full boundaries. These values are loaded into internal offset registers at reset and can be reprogrammed via D0–D11 and the LD/WEN sequence without halting FIFO operation.

Is 72V235L15TFGI pin-compatible with other members of the IDT72V2xx family?

Yes, all IDT72V2xx devices (72V205/215/225/235/245) share identical 64-pin TQFP/STQFP footprints and pin assignments. This enables drop-in depth scaling - for example, replacing 72V235L15TFGI with 72V245L15TFGI doubles buffer depth while retaining identical PCB layout and interface logic.