Texas Instruments SN74ACT72231L50RJ

Overview

SN74ACT72231L50RJ from Texas Instruments is a 2048 × 9-bit synchronous dual-clock FIFO memory IC with CMOS dual-port SRAM architecture, 15 ns write/read cycle time, TTL-compatible inputs, and programmable almost-empty/almost-full flags (default offsets: empty+7 / full−7). It operates from 0°C to 70°C and is used in high-speed asynchronous data bridging between mismatched buses in communication systems.

For engineers reviewing the SN74ACT72231L50RJ datasheet, SN74ACT72231L50RJ pinout, SN74ACT72231L50RJ application, or SN74ACT72231L50RJ equivalent, key selection criteria include its 2048-word depth, 9-bit data width with parity support, independent RCLK/WCLK operation, flag synchronization timing, and RJ-package thermal/mechanical compatibility with legacy 32-pin PLCC footprints.

Technical Context

This device implements a first-in, first-out buffer using internal synchronous read/write address counters, where WCLK controls write pointer advancement and RCLK controls read pointer advancement. Full (FF) and empty (EF) flags are synchronized to WCLK and RCLK respectively via single flip-flops, enforcing strict boundary enforcement during concurrent access.

Flag programming is enabled by configuring WEN2/LD as load (LD) input during reset, allowing sequential write/read of four 8-bit offset registers (empty LSB/MSB, full LSB/MSB) via WCLK/RCLK edges. Default offsets are fixed at 7 for both empty and full boundaries, yielding PAE low at ≤7 unread words and PAF low at ≥2041 unread words (2048 − 7).

Key Specifications

Pinout & Package

SN74ACT72231L50RJ is housed in a 32-pin plastic J-leaded chip carrier (RJ package), measuring 13.3 mm × 13.3 mm with 1.27 mm lead pitch and gull-wing leads suitable for surface-mount reflow assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72231L15JI and SN74ACT72231L20RJ, SN74ACT72231L50RJ delivers the highest clock frequency capability (66.7 MHz) within the same physical footprint and functional interface, making it optimal for bandwidth-constrained designs requiring maximum FIFO throughput without redesigning PCB layout.

Availability

SN74ACT72231L50RJ is available at Aetrix Electronics and suitable for high-speed communication queues, graphics system rate buffers, and industrial protocol gateways requiring stable component supply and long-term obsolescence management.

Supply support for SN74ACT72231L50RJ 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The SN74ACT72231L50RJ belongs to TI's ACT-family advanced CMOS FIFO product line, designed specifically for robust, low-latency data buffering across asynchronous clock domains in real-time systems.

FAQ

What is the memory organization of the SN74ACT72231L50RJ?

The SN74ACT72231L50RJ implements a 2048 × 9-bit synchronous FIFO structure, meaning it stores 2048 words of 9-bit data. This configuration supports byte-wide transfers plus one parity or control bit, and is explicitly defined in the device family datasheet SCAS222 as the capacity for the SN74ACT72231L variant. The '50' suffix denotes 15 ns cycle time rating.

How does the SN74ACT72231L50RJ handle clock domain crossing between write and read operations?

The SN74ACT72231L50RJ uses fully independent WCLK and RCLK inputs with separate address counters and flag synchronization logic. EF and PAE are synchronized to RCLK edges, while FF and PAF are synchronized to WCLK edges. This architecture ensures deterministic timing behavior when bridging asynchronous clock domains without requiring external handshake signals or arbitration logic.

Can the programmable almost-empty and almost-full flags of the SN74ACT72231L50RJ be customized, and how?

Yes - the SN74ACT72231L50RJ supports customization of PAE and PAF thresholds via four 8-bit offset registers (empty LSB/MSB, full LSB/MSB). Configuration requires holding WEN2/LD low during RS reset to enable LD mode, then performing sequential WCLK↑ transitions to write values. Default offsets are 7, yielding PAE activation at ≤7 unread words and PAF at ≥2041 unread words.

What package type is used for the SN74ACT72231L50RJ, and what are its mechanical characteristics?

The SN74ACT72231L50RJ uses a 32-pin plastic J-leaded chip carrier (RJ package), as confirmed in the SCAS222 datasheet header and pin diagram. It measures 13.3 mm × 13.3 mm with 1.27 mm lead pitch and gull-wing leads. This package is compatible with standard surface-mount reflow profiles and provides thermal and mechanical stability for commercial-temperature applications.

Is the SN74ACT72231L50RJ pin-compatible with other devices in the SN74ACT722xxL family?

Yes - all members of the SN74ACT722xxL family (including SN74ACT72211L, SN74ACT72221L, SN74ACT72231L, and SN74ACT72241L) share identical pinouts, control signal definitions, and flag behaviors. The only differences are memory depth (512/1024/2048/4096 words) and corresponding timing parameters; thus SN74ACT72231L50RJ can be substituted in layouts designed for any variant with appropriate firmware adjustment for depth-dependent flag calculations.