Texas Instruments SN74ACT72211L15RJ

Overview

SN74ACT72211L15RJ from Texas Instruments is a 512 × 9-bit synchronous FIFO memory IC with dual-clock operation, 15 ns write/read cycle time, TTL-compatible inputs, and programmable almost-empty/almost-full flags. It implements first-in-first-out buffering in asynchronous bus bridging applications such as graphics rate buffers and communication system queues.

For engineers reviewing the SN74ACT72211L15RJ datasheet, SN74ACT72211L15RJ pinout, SN74ACT72211L15RJ application, or SN74ACT72211L15RJ equivalent, this page delivers verified timing parameters, flag programming behavior, RJ-package terminal mapping, and direct alternatives for FIFO-based data channel design.

Technical Context

This device integrates CMOS dual-port SRAM with synchronous read/write control logic, using independent WCLK and RCLK inputs that support either asynchronous or coincident operation. Its internal address counters manage FIFO pointer advancement, while status flags (EF, FF, PAE, PAF) are synchronized to respective clocks via single-stage flip-flops.

Flag offset registers (8-bit LSB/MSB per boundary) enable configurable trigger thresholds for PAE and PAF; default offsets are empty+7 and full−7. The WEN2/LD pin's function-second write-enable or load control-is determined by its logic level during reset, defining whether programmable flags are active.

Key Specifications

Pinout & Package

SN74ACT72211L15RJ is housed in a 32-pin plastic J-leaded chip carrier (RJ package), with gull-wing leads suitable for surface-mount assembly and thermal performance matching industry-standard 32-pin CLCC footprints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72211L15JI and SN74ACT72211L20RJ, SN74ACT72211L15RJ delivers the highest clock frequency (66.7 MHz) within its commercial temperature grade, making it optimal for space-constrained, high-throughput applications where extended temp rating or timing margin is not required.

Availability

SN74ACT72211L15RJ is available at Aetrix Electronics and suitable for graphics rate buffering, communication system queuing, and industrial bus bridging requiring stable component supply across production lifecycles.

Supply support for SN74ACT72211L15RJ 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 SN74ACT72211L15RJ belongs to TI's ACT-family advanced CMOS FIFO product line, engineered for high-speed, low-power asynchronous data channeling in systems demanding deterministic latency and robust flag signaling.

FAQ

What is the memory organization of the SN74ACT72211L15RJ?

The SN74ACT72211L15RJ features a 512 × 9-bit synchronous FIFO memory structure, meaning it stores 512 words of 9-bit data each. This configuration supports byte-wide transfers plus one parity or control bit, and is implemented using CMOS dual-port SRAM with internal read/write address counters managing first-in-first-out data flow.

How does the SN74ACT72211L15RJ handle flag synchronization across clock domains?

The SN74ACT72211L15RJ synchronizes EF and PAE to the rising edge of RCLK using dedicated flip-flops, while FF and PAF are synchronized to WCLK edges. This ensures metastability-free status reporting when read and write clocks operate asynchronously-a key requirement for reliable cross-domain handshaking in the SN74ACT72211L15RJ.

Can the SN74ACT72211L15RJ be configured for programmable almost-full and almost-empty flags?

Yes-the SN74ACT72211L15RJ supports programmable PAE and PAF flags via four 8-bit offset registers. When WEN2/LD is held low during reset, it becomes a load enable, allowing sequential WCLK↑ transitions to write empty/full LSB/MSB values. Default offsets are empty+7 and full−7, but custom thresholds (e.g., 16 or 480) can be set for adaptive flow control.

What is the role of the WEN2/LD pin on the SN74ACT72211L15RJ?

The WEN2/LD pin on the SN74ACT72211L15RJ is a dual-function terminal whose behavior is determined at reset: if held high during RS deassertion, it acts as a second write-enable (WEN2); if held low, it becomes the load (LD) signal for programming PAE/PAF offset registers. This configuration choice defines whether programmable flags are enabled in the SN74ACT72211L15RJ.

Is the SN74ACT72211L15RJ compatible with TTL-level logic interfaces?

Yes-the SN74ACT72211L15RJ has TTL-compatible inputs with VIH(min) = 2.0 V and VIL(max) = 0.8 V, ensuring direct interoperability with standard 5-V TTL, LS, and F-series logic families without level-shifting circuitry. Its outputs also drive standard TTL loads, making the SN74ACT72211L15RJ ideal for mixed-logic-system integration.