Texas Instruments SN74ACT7813-25DL

Overview

SN74ACT7813-25DL from Texas Instruments is a 64-word × 18-bit clocked FIFO memory IC designed for high-speed asynchronous data buffering between independent clock domains. It supports free-running, asynchronous or coincident read/write clocks up to 40 MHz, delivers 12 ns access time with 50-pF load, features synchronized input-ready (IR) and output-ready (OR) flags, and operates across 0°C to 70°C.

For engineers reviewing the SN74ACT7813-25DL datasheet, SN74ACT7813-25DL pinout, SN74ACT7813-25DL application, or SN74ACT7813-25DL equivalent, this page provides verified timing parameters, flag synchronization behavior, bidirectional configuration capability, programmable almost-full/empty thresholds, and SSOP-56 package interface details essential for clock-domain bridging in telecom, test equipment, and digital signal processing systems.

Technical Context

The SN74ACT7813-25DL implements dual-synchronous control logic: write operations are edge-triggered on WRTCLK rising edge under WRTEN1/WRTEN2/IR conditions, while reads are triggered on RDCLK rising edge under RDEN/OE1/OE2/OR conditions. All status flags (IR, OR, HF, AF/AE) are fully synchronized to their respective clock domains.

It integrates a 64 × 18 RAM core with dedicated read/write pointer logic, programmable AF/AE offset registers (X/Y = 0–31, default 8), and output edge control (OEC™) circuitry to suppress simultaneous switching noise. Reset requires four rising edges on both clocks while RESET is asserted, initializing all flags to defined states.

Key Specifications

Pinout & Package

Packaged in shrink small-outline package (SSOP) with 56 pins, 300-mil body width, and 25-mil center-to-center lead pitch (DL package). Features distributed VCC/GND pins and OEC™ output edge control for noise suppression.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ACT7813-25DL, SN74ACT7803-25DL reduces per-device width but increases system-level component count, while SN74ACT7805-25DL trades depth for latency - making SN74ACT7813-25DL optimal for balanced 64-word, 18-bit, sub-12-ns buffering needs.

Availability

SN74ACT7813-25DL is available at Aetrix Electronics and suitable for telecom infrastructure, automated test equipment, industrial PLC communication modules, and broadcast video synchronizers requiring stable component supply and long-term obsolescence management.

Supply support for SN74ACT7813-25DL 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 SN74ACT7813-25DL belongs to TI's Widebus™ family of advanced CMOS FIFOs, engineered specifically for robust clock-domain bridging in high-speed digital systems where deterministic latency and noise immunity are critical.

FAQ

What is the maximum supported clock frequency for SN74ACT7813-25DL?

The SN74ACT7813-25DL supports a maximum clock frequency of 40 MHz for both read and write operations, as specified in its -25 speed grade designation. This rating applies under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C) with CL = 50 pF. The 12 ns access time and timing parameters in the datasheet are validated at this frequency, ensuring reliable setup/hold margin in synchronous FIFO applications.

How does the AF/AE flag programming work on SN74ACT7813-25DL?

On SN74ACT7813-25DL, the AF/AE flag uses two independently programmable offsets: AE value (X) and AF value (Y), each ranging 0–31. After reset and before the first write, asserting PEN low during a WRTCLK rising edge latches D0–D4 as X; a second PEN low pulse latches Y. If PEN remains high, default values X=Y=8 apply. Programming disables writes until complete, and the flag goes high when memory contains ≤X or ≥(64−Y) words.

Is SN74ACT7813-25DL pin-compatible with other members of the ACT78xx family?

Yes, SN74ACT7813-25DL is pin-to-pin compatible with SN74ACT7803-25DL and SN74ACT7805-25DL in the DL (SSOP-56) package. All share identical pin assignments for clocks, enables, flags, and I/O buses. However, functional differences exist: SN74ACT7803 is 64×9-bit, SN74ACT7805 is 256×9-bit, while SN74ACT7813-25DL provides 64×18-bit depth-width balance - requiring no PCB changes but careful firmware and timing validation.

What is the purpose of the PEN pin on SN74ACT7813-25DL?

The PEN (Program Enable) pin on SN74ACT7813-25DL controls loading of AF/AE offset values into internal registers. During reset initialization, holding PEN low on successive WRTCLK rising edges captures D0–D4 as the AE offset (X) and then the AF offset (Y). PEN must remain high to retain default X=Y=8. While PEN is active, write operations are disabled regardless of WRTEN1/WRTEN2 state - ensuring safe configuration before normal operation begins.

Does SN74ACT7813-25DL require power-on reset sequencing?

Yes, SN74ACT7813-25DL must be reset upon power-up. The FIFO does not guarantee valid flag states or pointer alignment without an asserted RESET signal. TI specifies that RESET must be held low for at least four rising edges of both WRTCLK and RDCLK to initialize IR, OR, and HF flags low and AF/AE high. Failure to perform this reset may result in undefined output behavior or incorrect flag assertion during early operation of SN74ACT7813-25DL.