Texas Instruments SN74ACT7807-15PAG

Overview

SN74ACT7807-15PAG from Texas Instruments is a 2048-word × 9-bit clocked FIFO memory IC with independent asynchronous read/write clocks, 12 ns access time, 67 MHz maximum data rate, and programmable almost-full/almost-empty flags. It serves as a high-speed data buffering interface between mismatched clock domains in digital communication subsystems.

For engineers reviewing the SN74ACT7807-15PAG datasheet, SN74ACT7807-15PAG pinout, SN74ACT7807-15PAG application, or SN74ACT7807-15PAG equivalent, key selection criteria include its dual-synchronized flag architecture (IR/IR synchronized to WRTCLK, OR synchronized to RDCLK), 64-pin TQFP package with 3-state outputs, and support for word-width/depth cascading without external logic.

Technical Context

The SN74ACT7807-15PAG implements a synchronous dual-clock FIFO architecture with separate write-pointer and read-pointer control logic, enabling true asynchronous operation between WRTCLK and RDCLK domains. Its status-flag logic generates IR, OR, HF, and AF/AE outputs each synchronized to their respective clock edges-IR to WRTCLK↑, OR to RDCLK↑-ensuring timing-safe handshaking.

It features programmable AF/AE offset values (X/Y) set via D0–D8 and WRTEN1/DP9 during reset-initiated programming mode using PEN, with default X = Y = 256. The FIFO resets asynchronously and requires four WRTCLK↑ and four RDCLK↑ transitions under RESET low to initialize all flags and pointers.

Key Specifications

Pinout & Package

SN74ACT7807-15PAG uses a 64-pin Thin Quad Flat Package (TQFP) with 0.5 mm pitch, 10 mm × 10 mm body, and exposed thermal pad. Pin functions are validated per TI SCAS200D datasheet Figure 1 (PAG/PM top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7203L15TPG, SN74ACT7807-15PAG offers programmable AF/AE and HF flag for adaptive flow control; compared with SN74ACT7809-15PAG, it provides optimal depth for latency-critical 1–2 ms buffering while reducing power and cost.

Availability

SN74ACT7807-15PAG is available at Aetrix Electronics and suitable for telecom line cards, industrial PLCs, video frame rate converters, and automated test equipment requiring stable component supply and long-term obsolescence management.

Supply support for SN74ACT7807-15PAG 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 interface and memory products.

The SN74ACT7807-15PAG belongs to TI's ACT advanced CMOS logic family, designed specifically for high-speed, low-power, cross-domain data buffering in commercial-grade digital systems.

FAQ

What is the maximum clock frequency supported by the SN74ACT7807-15PAG?

The SN74ACT7807-15PAG supports a maximum clock frequency of 67 MHz for both WRTCLK and RDCLK inputs, as specified in the timing requirements table of the SCAS200D datasheet. 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 -15 suffix denotes the 15 ns speed grade, correlating directly to the 67 MHz limit.

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

The SN74ACT7807-15PAG requires RESET to be asserted low for at least four rising edges of WRTCLK and four rising edges of RDCLK to fully initialize internal pointers and flags. During this period, IR, OR, and HF are driven low while AF/AE is set high. This dual-clock edge-counting mechanism ensures deterministic reset completion regardless of relative clock phase or frequency mismatch.

Can the SN74ACT7807-15PAG be used in word-width expansion configurations?

Yes, the SN74ACT7807-15PAG supports native word-width expansion to 18 bits (2048 × 18) using two devices, as shown in Figure 10 of the SCAS200D datasheet. The architecture uses shared WRTCLK, RDCLK, RESET, PEN, and enable signals, with D9–D17 and Q9–Q17 routed to the second device - no additional logic or timing compensation is required.

What is the function of the PEN pin on the SN74ACT7807-15PAG?

The PEN (Program Enable) pin on the SN74ACT7807-15PAG activates the AF/AE offset programming mode only after reset and before the first write operation. When PEN is low during a WRTCLK↑ transition, the values on D0–D8 and WRTEN1/DP9 are latched as the almost-empty (X) and almost-full (Y) thresholds. PEN must remain high during normal operation to prevent unintended reprogramming.

Does the SN74ACT7807-15PAG support cascading for increased memory depth?

Yes, the SN74ACT7807-15PAG supports word-depth expansion to 4096 × 9 using two devices, as illustrated in Figure 9 of the SCAS200D datasheet. Cascading uses daisy-chained IR and OR flags with shared clocks and enables, allowing seamless extension of buffer depth without external arbitration logic or timing penalties.