Texas Instruments SN74ACT7807-15FN

Overview

SN74ACT7807-15FN from Texas Instruments is a 2048-word × 9-bit clocked FIFO memory IC with independent asynchronous read/write clocks, 12 ns access time at 50-pF load, and 67 MHz maximum data rate. It features synchronized input-ready (IR) and output-ready (OR) flags, programmable almost-full/almost-empty (AF/AE) thresholds, and 3-state outputs for bus interfacing in high-speed digital systems.

For engineers reviewing the SN74ACT7807-15FN datasheet, SN74ACT7807-15FN pinout, SN74ACT7807-15FN application, or SN74ACT7807-15FN equivalent, key selection considerations include its dual-clock synchronization architecture, 44-pin PLCC (FN) package compatibility, IR/OR flag timing alignment to WRTCLK/RDCLK edges, and support for word-width/depth cascading in data buffering designs.

Technical Context

The SN74ACT7807-15FN implements a synchronous first-in-first-out buffer with separate write-pointer and read-pointer logic, enabling concurrent read and write operations under free-running, asynchronous, or coincident RDCLK/WRTCLK clocks. Its status-flag logic generates IR on the second rising edge of WRTCLK after reset and OR on the third rising edge of RDCLK after first write.

Flag generation uses internal synchronizers tied to respective clock domains: IR is edge-synchronized to WRTCLK, OR to RDCLK, HF to RDCLK, and AF/AE to both clocks depending on configuration. The FIFO supports programmable AF/AE offsets (X/Y up to 1023) via PEN-controlled latching of D0–D8 and WRTEN1/DP9 during reset recovery.

Key Specifications

Pinout & Package

SN74ACT7807-15FN is housed in a 44-pin plastic leaded chip carrier (PLCC, FN package), surface-mountable with J-lead geometry and 1.27 mm pitch. The package supports reflow soldering and provides mechanical stability for high-reliability board assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ACT7805-15FN, the SN74ACT7807-15FN doubles buffer depth without increasing pin count or timing overhead; versus 7205L15TPG, it adds flexible AF/AE threshold control at the cost of PLCC packaging and slightly higher complexity in initialization sequence.

Availability

SN74ACT7807-15FN is available at Aetrix Electronics and suitable for high-speed data acquisition, asynchronous bus bridging, telecom line card buffering, and digital signal processing pipeline applications requiring stable component supply across extended production lifecycles.

Supply support for SN74ACT7807-15FN 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 innovation in high-performance interface and memory products.

The SN74ACT7807-15FN belongs to TI's ACT family of advanced CMOS FIFOs, engineered for robust clock-domain isolation and deterministic data staging in mission-critical communication and instrumentation systems.

FAQ

What is the minimum pulse width required for WRTCLK and RDCLK on the SN74ACT7807-15FN?

The SN74ACT7807-15FN requires a minimum pulse width of 6 ns for both WRTCLK and RDCLK high and low states under the –15 speed grade. This specification ensures reliable register sampling and flag synchronization, and is verified at VCC = 4.5 V to 5.5 V and TA = 0°C to 70°C per the SCAS200D datasheet timing tables.

How does the SN74ACT7807-15FN handle reset synchronization across asynchronous clocks?

The SN74ACT7807-15FN requires four rising edges of both WRTCLK and RDCLK while RESET is asserted low to fully initialize internal pointers and flags. This dual-clock reset sequence guarantees metastability-free clearing of synchronizing registers, setting IR, OR, and HF low and AF/AE high - a requirement explicitly defined in the functional description and timing diagrams of the SN74ACT7807-15FN datasheet.

Can the SN74ACT7807-15FN be used in cascaded configurations for wider data paths?

Yes, the SN74ACT7807-15FN supports word-width expansion to 2048 × 18 bits using two devices, as shown in Figure 10 of the SN74ACT7807-15FN datasheet. Control signals (WRTCLK, RDCLK, WRTEN1/DP9, WRTEN2, RDEN1, RDEN2, OE, RESET, PEN) are shared, while D0–D8 and Q0–Q8 are paired with D9–D17 and Q9–Q17 respectively, maintaining full functionality and flag coherence.

What is the role of the PEN pin during AF/AE programming on the SN74ACT7807-15FN?

The PEN pin on the SN74ACT7807-15FN enables latching of D0–D8 and WRTEN1/DP9 as programmable AF/AE offset values. When PEN is pulled low during the reset recovery window (after IR goes high but before first write), the next rising edge of WRTCLK captures X (almost-empty), and a second rising edge captures Y (almost-full), as detailed in Section 6 of the SN74ACT7807-15FN datasheet.

Does the SN74ACT7807-15FN support 3.3-V operation?

No, the SN74ACT7807-15FN is specified only for 4.5 V to 5.5 V supply operation, with VIH = 2.0 V and VIL = 0.8 V thresholds aligned to 5-V TTL logic levels. It lacks 3.3-V compatibility per its recommended operating conditions table; use of 3.3-V supplies risks undefined behavior and violates absolute maximum ratings.