Texas Instruments SN74ACT72231L15RJ

Overview

SN74ACT72231L15RJ 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. It operates in 0°C to 70°C ambient and is used in high-speed data buffering between asynchronous buses in communication systems.

For engineers reviewing the SN74ACT72231L15RJ datasheet, SN74ACT72231L15RJ pinout, SN74ACT72231L15RJ application, or SN74ACT72231L15RJ equivalent, key selection factors include its 2048-word depth, 9-bit data width with parity support, independent RCLK/WCLK timing, flag synchronization logic, and RJ-package compatibility with IDT72231 family devices.

Technical Context

This FIFO implements first-in-first-out data flow using internal read/write address counters synchronized to separate RCLK and WCLK inputs. Its dual-port SRAM core supports fully asynchronous clock domains or coincident single-clock operation, with EF/FF flags synchronized to RCLK/WCLK respectively via flip-flops.

Flag behavior is determined by pointer arithmetic: EF asserts low when read/write pointers match; FF asserts low after exactly 2048 writes; PAE/PAF default to empty+7/full−7 offsets and are programmable via WEN2/LD-controlled register writes during reset configuration.

Key Specifications

Pinout & Package

SN74ACT72231L15RJ uses a 32-pin plastic J-leaded chip carrier (RJ) package with gull-wing leads, designed for surface-mount assembly and thermal reliability in high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72231L15JI and SN74ACT72231L20RJ, SN74ACT72231L15RJ delivers optimal performance at 66.7 MHz within commercial temperature limits, offering the highest speed among functionally compatible FIFOs without extended temp qualification or relaxed timing.

Availability

SN74ACT72231L15RJ is available at Aetrix Electronics and suitable for graphics rate buffering, high-speed communication queuing, and industrial bus bridge interfaces requiring stable component supply across production lifecycles.

Supply support for SN74ACT72231L15RJ 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 SN74ACT72231L15RJ belongs to TI's ACT-family advanced CMOS FIFO product line, engineered for high-speed, low-power data buffering in systems requiring deterministic latency and robust cross-domain synchronization.

FAQ

What is the memory organization of the SN74ACT72231L15RJ?

The SN74ACT72231L15RJ contains 2048 words of 9-bit synchronous FIFO memory implemented in CMOS dual-port SRAM. This 2048 × 9 structure provides 18,432 bits of elastic buffer storage, supporting byte-wide data plus parity or protocol framing bits, and is explicitly defined in the SCAS222 datasheet revision June 1993.

Does the SN74ACT72231L15RJ support asynchronous read and write clocks?

Yes, the SN74ACT72231L15RJ supports fully asynchronous operation of RCLK and WCLK - they may run at different frequencies, phases, or even be stopped independently. The device also permits coincident (same-source) clocking for single-clock system integration, as confirmed in the functional description and timing diagrams of the SCAS222 datasheet.

How are the programmable almost-empty and almost-full flags configured on the SN74ACT72231L15RJ?

The SN74ACT72231L15RJ uses the WEN2/LD pin during reset to enter flag programming mode. When held low at reset, it becomes a load control enabling sequential writes to four 8-bit offset registers via WCLK edges. Default values are empty+7 and full−7, yielding PAE assert at ≤7 words and PAF assert at ≥2041 words.

What is the purpose of the RS (reset) input on the SN74ACT72231L15RJ?

The RS input on the SN74ACT72231L15RJ performs asynchronous initialization: it sets read/write pointers to zero, clears the output register (Q0–Q8 = low), forces FF and PAF high, and sets EF and PAE low. A valid reset is mandatory after power-up before any write operation, as specified in the device reset section of SCAS222.

Is the SN74ACT72231L15RJ pin-compatible with IDT72231-series FIFOs?

Yes, the SN74ACT72231L15RJ is fully compatible with the IDT72231/72221/72231/72241 family in pinout, electrical behavior, timing, and functional operation. The datasheet explicitly states "Fully Compatible With the IDT72211/72221/72231/72241", confirming drop-in usability in designs originally specifying IDT parts.