Texas Instruments SN74ACT72231L20RJR

Overview

SN74ACT72231L20RJR 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 supports asynchronous or coincident read/write clocks for data buffering between mismatched-rate buses.

For engineers reviewing the SN74ACT72231L20RJR datasheet, SN74ACT72231L20RJR pinout, SN74ACT72231L20RJR application, or SN74ACT72231L20RJR equivalent, key selection criteria include its 2048-word depth, 9-bit data path with parity support, RCLK/WCLK timing skew tolerance (tsk1 = 6 ns min), flag synchronization logic, and RJ package compatibility with IDT72231 family devices.

Technical Context

This FIFO implements first-in-first-out data flow using independent synchronous read and write address counters, with full/empty flags synchronized to RCLK and WCLK respectively. Its dual-purpose WEN2/LD pin determines configuration at reset-either as second write enable or load control for four 8-bit flag offset registers.

Flag behavior is defined by offset register values: PAE asserts low when unread words ≤ n (default n = 7); PAF asserts low when unread words ≥ (2048 − m) (default m = 7). All status outputs are single-edge synchronized flip-flop registered to their respective clocks.

Key Specifications

Pinout & Package

SN74ACT72231L20RJR is housed in a 32-pin plastic J-leaded chip carrier (RJ package), top-view pinout as documented in SCAS222 Figure 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72231L20J and SN74ACT72231L20JR, the SN74ACT72231L20RJR offers identical 2048 × 9 FIFO functionality and 15 ns timing but is distinguished by Texas Instruments' manufacturing traceability and TI-specific packaging logistics-making it optimal for TI-centric supply chains and long-term lifecycle management.

Availability

SN74ACT72231L20RJR is available at Aetrix Electronics and suitable for graphics subsystems, telecom packet queuing, industrial protocol translation, and test equipment data capture requiring stable component supply and guaranteed 15 ns timing performance.

Supply support for SN74ACT72231L20RJR 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 with over 50 years of innovation in high-reliability timing and interface ICs.

The SN74ACT72231L20RJR belongs to TI's ACT logic FIFO product line, designed specifically for high-speed, low-latency data buffering between asynchronous digital subsystems in commercial and industrial environments.

FAQ

What is the memory organization of the SN74ACT72231L20RJR?

The SN74ACT72231L20RJR contains 2048 words of 9-bit synchronous FIFO memory implemented in CMOS dual-port SRAM. This yields a total capacity of 18,432 bits, structured for first-in-first-out data flow with independent read and write address pointers managed by RCLK and WCLK respectively.

Does the SN74ACT72231L20RJR support programmable almost-full and almost-empty flags?

Yes, the SN74ACT72231L20RJR supports fully programmable almost-full (PAF) and almost-empty (PAE) flags via four 8-bit offset registers. When configured with WEN2/LD as LD (low at reset), these registers can be written or read using WCLK/RCLK edges to set custom trigger thresholds beyond the default empty+7 and full−7 values.

What package type is used for the SN74ACT72231L20RJR?

The SN74ACT72231L20RJR is packaged in a 32-pin plastic J-leaded chip carrier (RJ package), compliant with JEDEC MS-018. This surface-mount package features gull-wing leads and is optimized for high-density PCB layouts requiring robust thermal and mechanical reliability in commercial temperature environments.

How does the SN74ACT72231L20RJR handle clock domain crossing between read and write operations?

The SN74ACT72231L20RJR handles clock domain crossing using synchronized status flags: EF and PAE are registered to RCLK, while FF and PAF are registered to WCLK. This ensures metastability-free boundary detection and deterministic read/write enable gating without external synchronizers.

Is the SN74ACT72231L20RJR compatible with the IDT72231 family of FIFOs?

Yes, the SN74ACT72231L20RJR is fully compatible with the IDT72231 family, including pinout, timing, flag behavior, and functional operation. Texas Instruments explicitly states this compatibility in the datasheet, enabling direct substitution in existing IDT72231L-based designs without layout or firmware changes.