Texas Instruments SN74V3650-7PEU

Overview

SN74V3650 from Texas Instruments is a 3.3-V CMOS synchronous FIFO memory with 2048 × 36-bit depth, 166-MHz operation (6-ns read/write cycle time), user-selectable ×36/×18/×9 bus matching on independent read/write ports, and zero-latency retransmit capability. It serves as a high-bandwidth data buffer in network packet processing pipelines where clock domain bridging and burst-mode data alignment are required.

For engineers reviewing the SN74V3650 datasheet, SN74V3650 pinout, SN74V3650 application, or SN74V3650 equivalent, key selection considerations include its FWFT/standard timing mode configurability, programmable almost-empty/almost-full flag offsets, big-endian/little-endian byte ordering, 5-V-tolerant inputs, and 128-pin TQFP package compatibility with depth/width expansion architectures.

Technical Context

The SN74V3650 implements a dual-clock, asynchronous-read/write architecture with fully independent RCLK and WCLK domains operating up to 166 MHz. Its RAM array supports fixed first-word latency and zero-latency retransmit via RM-controlled timing mode selection during master reset.

Bus-matching logic (BM/IW/OW) configures input/output port widths at power-up, while FWFT/SI determines timing behavior-FWFT enables automatic first-word output after three RCLK edges without REN assertion, whereas standard mode requires explicit REN activation for all reads including the first word.

Key Specifications

Pinout & Package

SN74V3650 is housed in a 128-pin Thin Quad Flat Pack (TQFP) package with 0.4-mm lead pitch, designed for surface-mount assembly and thermal reliability in industrial-grade environments.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V3650 and NB3N502, SN74V3650 uniquely delivers 5-V-tolerant inputs, FWFT timing, zero-latency retransmit, and full bus-matching configurability - making it the only option supporting robust, expandable, mixed-voltage FIFO implementations in telecom and video infrastructure.

Availability

SN74V3650 is available at Aetrix Electronics and suitable for network packet buffering, video frame synchronization, telecom line card aggregation, signal processing pipeline interfaces, and high-speed data acquisition systems requiring stable component supply over extended production lifecycles.

Supply support for SN74V3650 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 technologies with broad industrial and communications portfolio coverage.

The SN74V3650 belongs to TI's high-speed synchronous FIFO product line, engineered specifically for clock-domain bridging and data-rate adaptation in networking, video, and telecommunications infrastructure equipment.

FAQ

What is the memory organization of the SN74V3650?

The SN74V3650 provides a 2048 × 36-bit synchronous FIFO memory structure, delivering 73,728 bits of total storage. This organization supports high-bandwidth data buffering in applications requiring deep, fast-access temporary storage with flexible bus-width adaptation. The SN74V3650 maintains this exact configuration across all operating modes and is distinct from other members of the SN74V36xx family such as the SN74V3640 (1024×36) or SN74V3660 (4096×36).

Does the SN74V3650 support 5-V logic inputs?

Yes, the SN74V3650 features 5-V-tolerant inputs on all control and data pins, allowing direct connection to 5-V microcontrollers, FPGAs, or ASICs without external level shifters. This tolerance applies regardless of the device's 3.3-V VCC supply and remains valid across the full industrial temperature range (0°C to 70°C). The SN74V3650 outputs are not 5-V tolerant and must interface only with 3.3-V–compatible receivers.

How does the First-Word Fall-Through (FWFT) mode work in the SN74V3650?

In FWFT mode, the first word written to an empty SN74V3650 appears on Q0–Q35 after exactly three rising edges of RCLK - no REN assertion is needed. Subsequent words still require REN activation. This mode is selected by holding FWFT/SI high during master reset (MRS low). The SN74V3650 retains this configuration until next MRS, enabling predictable low-latency startup in burst-oriented protocols like packet reception or video line capture.

Can the SN74V3650 be used to expand buffer depth beyond 2048 words?

Yes, the SN74V3650 supports depth expansion via daisy-chaining in FWFT mode: the Q outputs of one device connect directly to the D inputs of the next, with shared RCLK/WCLK and synchronized flag propagation. No external logic is required. This capability is intrinsic to the SN74V3650's architecture and verified in TI's SCAS668A datasheet Figures 11–14, enabling scalable buffers up to 32768×36 using SN74V3690 as final stage.

What is the difference between master reset (MRS) and partial reset (PRS) on the SN74V3650?

Master reset (MRS) initializes read/write pointers, clears all data, resets output register to zero, and reloads all configuration settings (FWFT/SI, BM, IW, OW, BE, RM, PFM, IP, FSEL0/1, LD). Partial reset (PRS) only resets pointers and output register - it preserves current timing mode, flag offsets, programming method, and endianness settings. Both are asynchronous, but PRS allows mid-operation recovery without losing programmed SN74V3650 operational state.