Texas Instruments SN74ALVC7804-25DL

Overview

SN74ALVC7804-25DL from Texas Instruments is a 512 × 18-bit asynchronous FIFO memory IC designed for high-speed data buffering in 3.3-V systems. It features 18 ns access time at 50-pF load, 40 MHz max clock rate, full/empty/half-full flags, and programmable almost-full/almost-empty thresholds. Used in digital video interfaces, protocol bridging, and burst-mode data acquisition where clock domain isolation is required.

For engineers reviewing the SN74ALVC7804-25DL datasheet, SN74ALVC7804-25DL pinout, SN74ALVC7804-25DL application, or SN74ALVC7804-25DL equivalent, key selection criteria include its 56-pin SSOP (DL) package, dual asynchronous clocks (LDCK/UNCK), 3-state outputs with OE control, and programmable AF/AE flag offsets-critical for latency-sensitive buffer management in mixed-clock-domain systems.

Technical Context

The SN74ALVC7804-25DL implements a 512-word × 18-bit static RAM core with independent write and read pointer logic. Load clock (LDCK) and unload clock (UNCK) operate asynchronously, enabling seamless data transfer between unrelated clock domains. Status flags (FULL, EMPTY, HF, AF/AE) are generated combinatorially from pointer comparison logic.

AF/AE flag behavior is configurable via D0–D7 during reset-initiated programming sequence with PEN control; default offset values are X = Y = 64. The device uses advanced low-voltage CMOS (ALVC) process, supporting 3.0–3.6 V VCC operation with TTL-compatible input thresholds and 3.3-V output swing.

Key Specifications

Pinout & Package

Packaged in 56-pin Shrink Small-Outline Package (SSOP-DL), 300-mil body width, 25-mil center-to-center lead pitch, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74ACT7804-25DL and 72V255L15TF, the SN74ALVC7804-25DL delivers optimal balance of 3.3-V compatibility, programmable occupancy thresholds, and proven reliability in volume production-making it the go-to choice for cost-sensitive, high-throughput buffering where precise buffer watermarking matters.

Availability

SN74ALVC7804-25DL is available at Aetrix Electronics and suitable for video frame buffering, protocol bridge interfaces, and burst-mode data acquisition requiring stable component supply, long-term lifecycle support, and consistent SSOP-DL packaging.

Supply support for SN74ALVC7804-25DL 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 90 years of innovation in high-reliability electronic components.

The SN74ALVC7804-25DL belongs to TI's ALVC logic family-designed specifically for 3.3-V high-speed data-path applications requiring low power, precise timing control, and robust noise immunity in industrial and communications equipment.

FAQ

What is the maximum data rate supported by the SN74ALVC7804-25DL?

The SN74ALVC7804-25DL supports a maximum clock frequency of 40 MHz on both LDCK and UNCK inputs, enabling sustained data transfer rates up to 40 million words per second. This is validated under recommended conditions (VCC = 3.3 V ± 0.3 V, CL = 50 pF, TA = 0°C to 70°C). Real-world throughput depends on flag response timing and host controller latency, but the SN74ALVC7804-25DL's 18 ns access time ensures minimal pipeline stalls during full-bandwidth operation.

How do I configure the almost-full/almost-empty (AF/AE) flag thresholds for the SN74ALVC7804-25DL?

To configure AF/AE thresholds for the SN74ALVC7804-25DL, assert RESET low, then hold PEN low before the first LDCK rising edge. On the first LDCK↑, D0–D7 latch the almost-empty offset (X); on the second LDCK↑, they latch the almost-full offset (Y). Both values range 0–255. If PEN remains high after reset, default values X = Y = 64 apply. The SN74ALVC7804-25DL ignores writes during programming, ensuring safe configuration before data flow begins.

Is the SN74ALVC7804-25DL pin-compatible with older TI FIFO devices?

Yes, the SN74ALVC7804-25DL is pin-compatible with the SN74ACT7804-25DL in the same 56-pin SSOP-DL package. Signal mapping, pin locations, and functional behavior-including FULL, EMPTY, HF, and AF/AE flag logic-are identical. This allows direct replacement in existing 5-V designs upgraded to 3.3-V operation, provided VCC and I/O voltage levels are adjusted accordingly. No PCB changes are required for the SN74ALVC7804-25DL swap-in.

What happens to the Q outputs during reset or when OE is high on the SN74ALVC7804-25DL?

During RESET assertion (low), the SN74ALVC7804-25DL clears internal pointers and sets status flags (FULL=high, EMPTY=low, HF=low, AF/AE=high), but Q outputs retain their last valid logic states-they are not forced to any defined level. When OE is high, all Q outputs enter high-impedance state immediately, isolating the bus. The SN74ALVC7804-25DL does not drive Q outputs to known logic levels during reset or disable; external pull-ups/downs may be needed for bus stability.

Does the SN74ALVC7804-25DL support synchronous or asynchronous operation between write and read ports?

The SN74ALVC7804-25DL supports fully asynchronous operation: LDCK and UNCK may run at different frequencies, phases, or even zero duty cycle (idle), with no requirement for synchronization. Its internal pointer logic prevents metastability by using Gray-coded counters and handshake-free status flags. This makes the SN74ALVC7804-25DL ideal for clock domain crossing-unlike synchronous FIFOs, it imposes no timing constraints between write and read clocks.