Texas Instruments SN74V3690-10PEU

Overview

SN74V3690-10PEU from Texas Instruments is a 32,768 × 36-bit, 3.3-V CMOS synchronous FIFO memory with independent read/write clocks, user-selectable ×36/×18/×9 bus matching, first-word fall-through (FWFT) or standard timing mode, and zero-latency retransmit capability - deployed in high-throughput network buffering and video frame synchronization systems.

For engineers reviewing the SN74V3690-10PEU datasheet, SN74V3690-10PEU pinout, SN74V3690-10PEU application, or SN74V3690-10PEU equivalent, key selection criteria include its 166-MHz operation (6-ns cycle time), 5-V-tolerant inputs, programmable almost-empty/almost-full flags with eight default offsets, dual reset (MRS/PRS), and 128-pin TQFP package compatibility with depth/width expansion architectures.

Technical Context

This FIFO implements a dual-clock, asynchronous read/write architecture with fully independent RCLK and WCLK domains (0–166 MHz), enabling seamless data rate bridging between mismatched subsystems. Its internal RAM array supports flexible bus sizing via BM/IW/OW configuration during master reset, and flag logic delivers deterministic latency for EF/OR, FF/IR, HF, PAE, and PAF signals.

The device integrates configurable timing modes: FWFT mode enables immediate first-word output after three RCLK edges without REN assertion, while standard mode requires explicit REN activation for all reads. Retransmit (RT) with zero-latency mode (selected via RM pin at MRS) resets the read pointer on-the-fly without disrupting write operations or flag state retention.

Key Specifications

Pinout & Package

SN74V3690-10PEU 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 (top view) and Terminal Functions table (pages 6–7).

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V3680L15PF and NB3N502FG, SN74V3690-10PEU uniquely combines maximum depth (32k × 36), 5-V-tolerant control inputs, FWFT timing, and zero-latency retransmit - making it the only option for high-fidelity, low-latency, mixed-voltage buffering in next-generation infrastructure equipment.

Availability

SN74V3690-10PEU is available at Aetrix Electronics and suitable for network packet buffering, video frame synchronization, telecom line card buffering, and signal processing data pipeline applications requiring stable component supply across extended production lifecycles.

Supply support for SN74V3690-10PEU 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 decades of leadership in high-speed interface and memory products.

SN74V3690-10PEU belongs to TI's high-performance FIFO memory family designed for deterministic, low-latency data buffering in telecommunications, networking, broadcast video, and test equipment where clock domain crossing and bus width mismatch are critical challenges.

FAQ

What is the maximum operating frequency of the SN74V3690-10PEU?

The SN74V3690-10PEU supports up to 166 MHz on both WCLK and RCLK inputs, corresponding to a 6-ns read/write cycle time. This specification is guaranteed over the full commercial temperature range (0°C to 70°C) and applies independently to each clock domain - no synchronization or frequency-ratio constraints exist between WCLK and RCLK.

Does the SN74V3690-10PEU support 5-V logic inputs?

Yes, the SN74V3690-10PEU features 5-V-tolerant control inputs including WCLK, RCLK, WEN, REN, MRS, PRS, OE, RT, FWFT/SI, BM, IW, OW, BE, RM, PFM, IP, FSEL0/1, and LD. These pins accept voltages from 0 V to 5.5 V while the device operates from a 3.3-V VCC supply - enabling direct interfacing with legacy 5-V logic without level shifters.

How does the first-word fall-through (FWFT) mode work in the SN74V3690-10PEU?

In FWFT mode (enabled by high FWFT/SI during MRS), the first word written to an empty SN74V3690-10PEU appears on Q0–Q35 after exactly three rising edges of RCLK - no REN assertion required. Subsequent words still require REN activation. This eliminates initial read latency in burst-oriented systems like video pipelines or packet reassembly engines.

Can the SN74V3690-10PEU be used to expand buffer depth beyond 32,768 words?

Yes, the SN74V3690-10PEU supports depth expansion via FWFT-mode chaining: connect Q outputs of one device directly to D inputs of the next. In FWFT mode, the first word from the upstream FIFO automatically propagates to downstream outputs, enabling seamless cascading without external control logic or timing compensation.

What is the function of the RM pin on the SN74V3690-10PEU?

The RM (Retransmit Latency Mode) pin on the SN74V3690-10PEU selects zero-latency or normal-latency retransmit behavior during master reset. When RM is low at MRS, asserting RT on a rising RCLK edge places the first retransmitted word on Q outputs within that same clock edge - critical for real-time retry protocols where pipeline stalls must be avoided.