Texas Instruments SN74V3680-6PEU

Overview

SN74V3680-6PEU from Texas Instruments is a 16,384 × 36-bit, 3.3-V CMOS synchronous FIFO memory with independent read/write clocks, user-selectable ×36/×18/×9 bus matching, and first-word fall-through (FWFT) or standard timing modes. It delivers 166-MHz operation (6-ns cycle time), zero-latency retransmit capability, and programmable almost-empty/almost-full flags - deployed in high-throughput network buffering and video data stream alignment.

For engineers reviewing the SN74V3680-6PEU datasheet, SN74V3680-6PEU pinout, SN74V3680-6PEU application, or SN74V3680-6PEU equivalent, key selection criteria include its 16,384 × 36-bit depth, 5-V-tolerant inputs, dual-clock domain support, FWFT/standard mode configurability, and TQFP-128 package compatibility for high-density PCB layouts.

Technical Context

This FIFO implements a dual-clock, asynchronous read/write architecture with fully independent RCLK and WCLK domains operating up to 166 MHz. Its internal RAM array supports flexible bus-matching via BM/IW/OW control pins during master reset, enabling ×36-to-×36, ×36-to-×18, ×36-to-×9, ×18-to-×36, or ×9-to-×36 configurations.

Flag logic includes EF/OR, FF/IR, HF, PAE, and PAF outputs - with PAE/PAF programmable via serial or parallel loading and configurable for synchronous or asynchronous timing via PFM. Retransmit functionality resets the read pointer on RT assertion, with zero-latency mode selectable via RM during master reset.

Key Specifications

Pinout & Package

SN74V3680-6PEU is housed in a 128-pin Thin Quad Flat Pack (TQFP) with 0.4-mm lead pitch and exposed thermal pad. Pin assignments are validated per TI SCAS668A datasheet Figure 2 (PEU package top view).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V3680L15PF and NB3N3020BDR2G, SN74V3680-6PEU uniquely combines 166-MHz speed, 5-V-tolerant inputs, zero-latency retransmit, and full FWFT/standard mode flexibility - making it optimal for next-generation high-bandwidth, mixed-voltage data concentrators.

Availability

SN74V3680-6PEU is available at Aetrix Electronics and suitable for network packet buffering, video frame synchronization, telecom line card aggregation, industrial sensor concentration, and high-speed protocol bridging requiring stable component supply across extended production lifecycles.

Supply support for SN74V3680-6PEU 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 timing and interface ICs.

The SN74V36xx family was designed specifically for high-throughput, low-latency data buffering in network infrastructure, broadcast video, and real-time signal processing systems demanding deep, flexible, and deterministic FIFO behavior.

FAQ

What is the maximum operating frequency of the SN74V3680-6PEU?

The SN74V3680-6PEU supports up to 166 MHz operation, corresponding to a 6-ns read/write cycle time. This specification is guaranteed across the full commercial temperature range (0°C to +70°C) and 3.3-V ±0.3-V supply. The device achieves this performance using high-speed submicron CMOS technology and is characterized with strict setup/hold timing margins relative to WCLK and RCLK rising edges.

Does the SN74V3680-6PEU support both FWFT and standard timing modes?

Yes, the SN74V3680-6PEU supports both first-word fall-through (FWFT) and standard timing modes. The mode is selected by the logic state of the FWFT/SI pin during master reset (MRS). In FWFT mode, the first word written to an empty FIFO appears at Qn after three RCLK edges without requiring REN assertion; in standard mode, all reads - including the first - require REN activation.

How is bus width configured on the SN74V3680-6PEU?

Bus width is configured using the BM (bus matching), IW (input width), and OW (output width) pins during master reset. These three inputs select one of five valid configurations: ×36-in to ×36-out, ×36-in to ×18-out, ×36-in to ×9-out, ×18-in to ×36-out, or ×9-in to ×36-out. Unused Dn and Qn pins enter a don't-care state in reduced-width modes.

Can the SN74V3680-6PEU be used with 5-V logic interfaces?

Yes, the SN74V3680-6PEU features 5-V-tolerant inputs on all control and data pins (D0–D35, WEN, REN, MRS, PRS, etc.), allowing direct connection to 5-V TTL or LVTTL drivers without external level shifters. Note that Q0–Q35 outputs are not 5-V tolerant and operate at 3.3-V levels regardless of OE state.

What is the purpose of the Partial Reset (PRS) function in the SN74V3680-6PEU?

The Partial Reset (PRS) function in the SN74V3680-6PEU resets the internal read and write pointers to zero and clears the output register, while preserving all programmable settings - including FWFT/standard mode, PAE/PAF offset values, PFM timing mode, and bus-width configuration. This enables safe mid-operation buffer clearing in real-time systems like audio DSP pipelines without losing critical configuration state.