Renesas 72235LB15PFGI8

Overview

IDT72235LB15PFGI8 from Integrated Device Technology is a 2,048 × 18-bit synchronous FIFO memory IC with dual-clock operation, 10 ns read/write cycle time, programmable Almost-Empty/Almost-Full flags, and industrial temperature range (–40°C to +85°C). It serves as a high-speed data buffer in interprocessor communication, LAN controllers, and optical disk interfaces.

For engineers reviewing the IDT72235LB15PFGI8 datasheet, IDT72235LB15PFGI8 pinout, IDT72235LB15PFGI8 application, or IDT72235LB15PFGI8 equivalent, key selection criteria include its 2,048-word depth, 18-bit bus width, asynchronous clock support, Half-Full flag capability, and TQFP-64 packaging for space-constrained embedded systems.

Technical Context

This FIFO 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 fixed (EF/FF) and programmable (PAE/PAF/HF) status signals synchronized to respective clocks (RCLK/WCLK).

The device uses high-performance submicron CMOS technology and supports depth expansion via daisy-chain configuration using WXI/WXO and RXI/RXO pins. Reset initialization sets internal pointers and default offsets (127 for PAE/PAF), and output enable (OE) provides three-state control of the Q0–Q17 bus.

Key Specifications

Pinout & Package

Package: 64-lead thin quad flatpack (TQFP-64), lead finish SnPb (end-of-life), industrial grade.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 72235L15TF8 and 72235LB15JGI8, the IDT72235LB15PFGI8 offers optimal balance of compact TQFP-64 footprint, industrial temperature rating, and SnPb solderability - making it ideal for cost-sensitive, high-volume industrial control designs requiring proven long-term availability.

Availability

IDT72235LB15PFGI8 is available at Aetrix Electronics and suitable for optical disk controllers, LAN interface cards, interprocessor communication links, and industrial PLC data acquisition systems requiring stable component supply across extended production lifecycles.

Supply support for IDT72235LB15PFGI8 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 data movement solutions.

The IDT722xxLB SyncFIFO product line was designed specifically for high-speed, low-latency data buffering in mixed-clock-domain systems - targeting applications demanding deterministic timing, expandable depth, and industrial reliability.

FAQ

What is the memory organization of IDT72235LB15PFGI8?

IDT72235LB15PFGI8 features a 2,048 × 18-bit synchronous FIFO memory array, meaning it stores up to 2,048 words of 18-bit data. This organization supports wide-data applications like video frame buffering and multi-channel sensor aggregation. The device uses dual-port zero fall-through architecture to ensure immediate read-after-write availability without pipeline delay.

Does IDT72235LB15PFGI8 support asynchronous clock domains?

Yes, IDT72235LB15PFGI8 supports fully asynchronous read and write clocks (RCLK and WCLK). Its flag logic (EF, FF, PAE, PAF) is synchronized to their respective clocks, enabling reliable handshaking across independent timing domains. This makes IDT72235LB15PFGI8 ideal for bridging CPU buses to peripherals with mismatched clock frequencies.

What is the default Almost-Empty offset for IDT72235LB15PFGI8?

The default Almost-Empty offset for IDT72235LB15PFGI8 is 127 words from empty, per the datasheet's specification for IDT72225LB/72235LB/72245LB family members. This value is loaded into the Empty Offset register at reset and can be reprogrammed via the LD pin and D0–D11 inputs during configuration mode.

Can IDT72235LB15PFGI8 be expanded in depth?

Yes, IDT72235LB15PFGI8 supports depth expansion via daisy-chain configuration using WXI/WXO and RXI/RXO pins. In this mode, FL is grounded on the first device and set HIGH on subsequent devices. Each device contributes its full 2,048-word depth, allowing scalable total buffer sizes while maintaining consistent timing behavior across the chain.

What package type and lead finish does IDT72235LB15PFGI8 use?

IDT72235LB15PFGI8 uses a 64-lead thin quad flatpack (TQFP-64, order code PF) with SnPb lead finish. This finish is in end-of-life process per the November 2017 datasheet, with last-time-buy expiration on June 15, 2018. Customers requiring RoHS compliance should consider the alternative 72235L15TF8 (STQFP-64, green finish).