Texas Instruments SN74ACT7205L20RJ

Overview

SN74ACT7205L20RJ from Texas Instruments is a 8192 × 9-bit asynchronous dual-port FIFO memory IC with independent read/write operations, 15 ns data access time, 40 MHz read/write frequency capability, and TTL-compatible inputs. It implements first-in-first-out buffering for rate-matching between asynchronous buses in data-acquisition systems.

For engineers reviewing the SN74ACT7205L20RJ datasheet, SN74ACT7205L20RJ pinout, SN74ACT7205L20RJ application, or SN74ACT7205L20RJ equivalent, key selection criteria include depth-expansion support, retransmit capability, empty/full/half-full flag outputs, and 32-pin PLCC (RJ) package compatibility with industrial temperature range (0°C to 70°C).

Technical Context

This device integrates dual-port SRAM with internal write and read address counters, enabling true FIFO operation without external control logic. Its architecture supports both asynchronous and coincident read/write cycles, with status flags (EF, FF, XO/HF) generated directly from pointer comparison logic.

Depth expansion is implemented via daisy-chained XI/XO signals across multiple devices, while width expansion uses parallel control lines and shared status flag monitoring. The FL/RT pin serves dual roles: first-load enable in depth expansion and retransmit trigger when XI = GND.

Key Specifications

Pinout & Package

SN74ACT7205L20RJ is housed in a 32-pin plastic J-leaded chip-carrier (PLCC) package (RJ), with gull-wing leads and a 1.27 mm pitch. The package is surface-mountable and RoHS-compliant per TI documentation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7205L20P and SN74ACT7205L20DW, SN74ACT7205L20RJ uniquely supports both depth expansion and retransmit in a surface-mount PLCC package-making it optimal for scalable, field-upgradeable industrial buffer designs requiring hardware-level data recovery.

Availability

SN74ACT7205L20RJ is available at Aetrix Electronics and suitable for data-acquisition systems, industrial bus bridges, UART protocol queues, and magnetic storage interfaces requiring stable component supply across extended production lifecycles.

Supply support for SN74ACT7205L20RJ 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 decades of heritage in high-reliability interface and memory products.

SN74ACT7205L20RJ belongs to TI's ACT-family advanced CMOS FIFO series, engineered specifically for robust, low-latency inter-bus buffering in industrial and instrumentation systems operating at 5 V.

FAQ

What is the memory depth and width of the SN74ACT7205L20RJ?

The SN74ACT7205L20RJ provides 8192 words of storage, each 9 bits wide (8192 × 9). This configuration supports byte-plus-parity data handling or packet framing with dedicated overhead bits. The depth is fixed per device but expandable via daisy-chained XI/XO connections across multiple SN74ACT7205L20RJ units.

Does the SN74ACT7205L20RJ support retransmission of previously read data?

Yes, the SN74ACT7205L20RJ supports retransmit functionality via the FL/RT pin when XI is grounded. A low pulse on FL/RT resets the internal read pointer to location zero without altering the write pointer-enabling hardware-level recovery of unread data for protocol retries or diagnostic replay.

What package type is used for the SN74ACT7205L20RJ?

The SN74ACT7205L20RJ uses a 32-pin plastic J-leaded chip-carrier (PLCC) package, designated "RJ" in TI's packaging nomenclature. It features gull-wing leads, 1.27 mm pitch, and is designed for surface-mount assembly with standard reflow profiles.

How does depth expansion work with multiple SN74ACT7205L20RJ devices?

Depth expansion uses the XI (expansion-in) and XO/HF (expansion-out) pins to daisy-chain devices. The first device has FL/RT grounded and XI tied low; subsequent devices have FL/RT high and XI connected to the prior device's XO/HF. This creates a unified FIFO with cumulative depth-e.g., two SN74ACT7205L20RJ units yield 16,384 × 9 capacity.

What are the key timing parameters for reliable operation of the SN74ACT7205L20RJ?

Key timing parameters include 15 ns data access time (ta), 25 ns minimum read/write cycle time (tc(R)/tc(W)), and 15 ns minimum pulse widths for R, W, RS, and FL/RT. Setup/hold times (e.g., tsu(D) = 11 ns, th(D) = 0 ns) must be met relative to clock edges to ensure deterministic FIFO behavior across temperature and voltage ranges.