Texas Instruments SN74ACT7807-25FN

Overview

SN74ACT7807-25FN from Texas Instruments is a 2048-word × 9-bit clocked FIFO memory IC with independent asynchronous read/write clocks, 12 ns access time, 40 MHz maximum clock frequency, and programmable almost-full/almost-empty flags. It serves as a high-speed data buffering interface between mismatched clock domains in digital communication and control systems.

For engineers reviewing the SN74ACT7807-25FN datasheet, SN74ACT7807-25FN pinout, SN74ACT7807-25FN application, or SN74ACT7807-25FN equivalent, key selection considerations include its 44-pin LCC (FN) package, synchronous flag behavior, 3-state outputs, word-width/depth cascading capability, and operation across 0°C to 70°C.

Technical Context

The SN74ACT7807-25FN implements a dual-clock FIFO architecture with fully independent WRTCLK and RDCLK inputs, each synchronizing respective control logic and status flags. Its internal 2048 × 9 RAM core supports noninverting parallel data transfer and features dedicated write-pointer and read-pointer logic with reset-synchronized initialization.

Status flag generation is tightly coupled to clock edges: IR is synchronized to WRTCLK rising edge, OR and HF to RDCLK rising edge, and AF/AE responds to both clocks depending on programmed offset values. The PEN-controlled offset programming mode enables configurable depth thresholds without requiring external logic.

Key Specifications

Pinout & Package

SN74ACT7807-25FN uses a 44-pin plastic leaded chip carrier (PLCC, FN package) with J-lead configuration and 1.27 mm pitch. The package is surface-mountable and thermally rated at θ_JA = 46°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7203L15TPG and SN74ACT7805-25FN, the SN74ACT7807-25FN delivers optimal balance of depth, speed, and 5-V compatibility in compact 44-pin PLCC - making it ideal for space-constrained, single-rail industrial designs requiring deterministic 2-kword buffering.

Availability

SN74ACT7807-25FN is available at Aetrix Electronics and suitable for network packet buffering, digital signal processing interfaces, industrial PLC I/O expansion, and video frame synchronization requiring stable component supply and long-term production continuity.

Supply support for SN74ACT7807-25FN 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions across industrial, automotive, and communications markets.

The SN74ACT7807-25FN belongs to TI's ACT-family advanced CMOS FIFO product line, engineered specifically for high-reliability, low-latency data buffering in multi-clock-domain digital systems where deterministic timing and flag-based flow control are critical.

FAQ

What is the maximum clock frequency supported by the SN74ACT7807-25FN?

The SN74ACT7807-25FN supports a maximum clock frequency of 40 MHz for both WRTCLK and RDCLK inputs. This rating is specified under recommended operating conditions (VCC = 4.5 V to 5.5 V, TA = 0°C to 70°C) and corresponds to the -25 speed grade. At this rate, the device sustains reliable read/write operations with guaranteed setup/hold timing margins and 12 ns access time.

How does the SN74ACT7807-25FN handle power-on initialization?

The SN74ACT7807-25FN requires an asynchronous RESET assertion upon power-up. RESET must remain low while at least four rising edges occur on both WRTCLK and RDCLK to properly initialize internal pointers and flags. After reset completion, IR, OR, and HF flags are set low, while AF/AE is set high. Failure to execute this sequence may result in undefined FIFO state or corrupted data transfer.

Can the SN74ACT7807-25FN be used in cascaded configurations for increased depth or width?

Yes, the SN74ACT7807-25FN supports both word-depth and word-width expansion. For depth expansion (e.g., 4096 × 9), two devices are connected with shared RDCLK/WRTCLK and daisy-chained IR/OR flags. For width expansion (e.g., 2048 × 18), multiple units share clocks and enables while concatenating D0–D8 and Q0–Q8 buses. TI Application Note SCAS200D provides verified schematics and timing diagrams for both topologies using SN74ACT7807-25FN.

What is the function of the PEN pin on the SN74ACT7807-25FN?

The PEN (Program Enable) pin on the SN74ACT7807-25FN controls programming of the AF/AE flag offset values. After reset and before the first write, asserting PEN low during a WRTCLK rising edge latches D0–D8 and WRTEN1/DP9 as the almost-empty (X) offset. A second low PEN pulse programs the almost-full (Y) offset. During programming, no data is written to memory regardless of WRTEN states. Default X=Y=256 applies if PEN remains high.

Does the SN74ACT7807-25FN support 3.3-V logic interfaces?

No, the SN74ACT7807-25FN is designed exclusively for 5-V operation, with recommended VCC range of 4.5 V to 5.5 V and absolute maximum VI of –0.5 V to 7 V. Its input thresholds (VIH = 2.0 V, VIL = 0.8 V) and output drive strength (16 mA sink) are optimized for TTL/CMOS 5-V systems. Interfacing with 3.3-V logic requires level translation circuitry; TI does not specify or guarantee 3.3-V compatibility for SN74ACT7807-25FN.