Texas Instruments SN74ALVC7814-25DLR

Overview

SN74ALVC7814-25DLR from Texas Instruments is a low-power 64 × 18-bit asynchronous FIFO memory IC designed for high-speed data buffering between mismatched clock domains. It operates from 3.0 V to 3.6 V, delivers 18 ns access time at 50-pF load, supports up to 40 MHz data rates, and provides full/empty/half-full/programmable almost-full/almost-empty flags. It is used in digital video interfaces, network packet buffering, and multi-clock domain bridging.

For engineers reviewing the SN74ALVC7814-25DLR datasheet, SN74ALVC7814-25DLR pinout, SN74ALVC7814-25DLR application, or SN74ALVC7814-25DLR equivalent, key selection criteria include its 18-bit parallel I/O width, dual asynchronous clocks (LDCK/UNCK), programmable AF/AE flag offsets, 3-state outputs with OE control, and SSOP-56 package compatibility with legacy Widebus™ FIFO designs.

Technical Context

The SN74ALVC7814-25DLR implements a synchronous-write/asynchronous-read FIFO architecture with independent load and unload clocks. Its internal 64-word × 18-bit RAM uses advanced CMOS logic to support coincident or fully asynchronous clocking, enabling seamless data transfer across domains without handshake logic.

Status monitoring relies on dedicated open-drain-compatible flag outputs (FULL, EMPTY, HF, AF/AE) with defined active-low polarity and programmable depth thresholds. Reset initialization sets FULL high and EMPTY low while preserving Q-output states, and AF/AE offset values (X/Y) are latched via D0–D7 during the first two LDCK edges after reset when PEN is low.

Key Specifications

Pinout & Package

Packaged in a 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 SN74ALVC7814-40DLR, the SN74ALVC7814-25DLR trades maximum clock speed for tighter timing margins and lower dynamic power at sub-25-MHz operation; versus SN74ACT7814DW, it enables 3.3-V native operation, programmable flags, and 60% lower ICC, making it optimal for modern low-voltage embedded buffering.

Availability

SN74ALVC7814-25DLR is available at Aetrix Electronics and suitable for video frame buffering, network packet buffering, and industrial PLC communication bridges requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for SN74ALVC7814-25DLR 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 SN74ALVC7814-25DLR belongs to TI's Widebus™ family of high-speed interface logic, engineered specifically for low-voltage, low-power asynchronous data buffering in multi-clock domain systems.

FAQ

What is the maximum clock frequency supported by the SN74ALVC7814-25DLR?

The SN74ALVC7814-25DLR is characterized for operation up to 25 MHz, as indicated by the "-25" suffix in its part number. This rating reflects guaranteed timing performance under recommended operating conditions (VCC = 3.0 V to 3.6 V, TA = 0°C to 70°C). While some units may operate beyond this frequency, the 25-MHz specification ensures reliable access time (≤18 ns), setup/hold compliance, and flag propagation delay margins across temperature and voltage extremes. The SN74ALVC7814-25DLR must not be operated above 25 MHz in production designs unless re-characterized per application-specific validation.

How does the AF/AE flag programming work on the SN74ALVC7814-25DLR?

After asserting RESET low and releasing it high, the SN74ALVC7814-25DLR enters programming mode when PEN is held low. On the first rising edge of LDCK, the binary value present on D0–D7 is latched as the almost-empty offset (X); on the second rising LDCK edge, the same bus value sets the almost-full offset (Y). Both X and Y are programmable from 0 to 32. The SN74ALVC7814-25DLR then exits programming mode, and subsequent LDCK edges resume normal write operations. If PEN remains high, default offsets (X = Y = 8) apply.

Can the SN74ALVC7814-25DLR be used with a 5-V system?

No, the SN74ALVC7814-25DLR is strictly a 3.3-V device with absolute maximum VCC of 4.6 V and recommended operating range of 3.0 V to 3.6 V. Applying 5 V violates absolute maximum ratings and risks permanent damage. For 5-V systems, TI offers the pin-compatible SN74ACT7814DW, which uses TTL-compatible thresholds and 5-V supply. Interfacing the SN74ALVC7814-25DLR with 5-V logic requires bidirectional level translators - direct connection will cause overvoltage stress on inputs and unreliable flag/output behavior.

What happens to the Q outputs during reset of the SN74ALVC7814-25DLR?

During RESET assertion (low), the SN74ALVC7814-25DLR resets internal read/write pointers and forces FULL high, EMPTY low, HF low, and AF/AE high, but the Q0–Q17 outputs retain their last driven logic states and are not forced to any defined level. Once RESET is released and the first word is loaded, valid data appears on Q outputs synchronized to the next UNCK rising edge. To ensure known output states at power-up, external pull-downs or an initial dummy read cycle is recommended - the SN74ALVC7814-25DLR itself does not initialize Q outputs.

Is the SN74ALVC7814-25DLR pin-compatible with other Widebus™ FIFOs?

Yes, the SN74ALVC7814-25DLR is explicitly documented as pin-to-pin compatible with SN74ACT7804, SN74ACT7806, and SN74ACT7814 in the datasheet. All share identical 56-pin SSOP-DL packaging, matching pin functions (including RESET, LDCK, UNCK, OE, FULL, EMPTY, HF, AF/AE, D0–D17, Q0–Q17), and compatible voltage thresholds. This allows direct substitution in existing ACT-based designs, though users must verify VCC compatibility (3.3 V vs. 5 V) and update timing constraints to match ALVC characteristics.