Texas Instruments SN74V3660-6PEU

Overview

SN74V3660-6PEU from Texas Instruments is a 4096 × 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 packet buffering and video frame synchronization.

For engineers reviewing the SN74V3660-6PEU datasheet, SN74V3660-6PEU pinout, SN74V3660-6PEU application, or SN74V3660-6PEU equivalent, key selection criteria include configurable bus-width matching, FWFT vs. standard timing mode selection at master reset, 5-V-tolerant inputs, fixed low first-word latency, and support for depth expansion via serial chaining without external logic.

Technical Context

This FIFO implements dual-clock architecture with fully asynchronous WCLK and RCLK domains (0–166 MHz), enabling simultaneous read/write operations across clock domain boundaries. Its internal RAM array is paired with programmable flag logic that supports eight preselected offset values for PAE/PAF, loaded either serially via FWFT/SI or in parallel via Dn/Qn under LD control.

Bus configuration is determined at master reset by BM, IW, and OW pins - selecting among five input/output width combinations (e.g., ×36→×36, ×36→×18, ×18→×36). Big-endian/little-endian byte ordering and interspersed/noninterspersed parity are also set during MRS, while PFM selects synchronous or asynchronous flag timing for PAE/PAF.

Key Specifications

Pinout & Package

SN74V3660-6PEU is housed in a 128-pin Thin Quad Flat Pack (TQFP) with 0.4-mm pitch, RoHS-compliant lead finish, and thermal pad exposed on underside for enhanced power dissipation in sustained 166-MHz operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72V3640L15PF and NB3N502FG, SN74V3660-6PEU uniquely combines 4096×36 depth, FWFT timing, zero-latency retransmit, and full ×36/×18/×9 bus matching - making it optimal for latency-constrained, multi-standard interface bridging where configuration flexibility and deterministic timing are mandatory.

Availability

SN74V3660-6PEU is available at Aetrix Electronics and suitable for network packet buffering, video frame synchronization, telecom line card interface, and DSP data pipeline buffering requiring stable component supply across extended production lifecycles.

Supply support for SN74V3660-6PEU 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 decades of leadership in high-performance memory and interface ICs.

SN74V3660-6PEU belongs to TI's high-speed synchronous FIFO product line, engineered specifically for clock-domain bridging in networking, video, and telecommunications infrastructure where deterministic latency, deep buffering, and flexible bus interfacing are critical.

FAQ

What is the memory organization of the SN74V3660-6PEU?

The SN74V3660-6PEU implements a 4096 × 36-bit first-in, first-out memory array, delivering 147,456 bits of total storage. This organization is fixed for the SN74V3660-6PEU variant and distinct from other family members such as SN74V3640 (1024 × 36) or SN74V3670 (8192 × 36). The memory is implemented in high-speed submicron CMOS and supports simultaneous read/write operations via independent clock domains.

Does the SN74V3660-6PEU support 5-V logic inputs?

Yes, the SN74V3660-6PEU features 5-V-tolerant inputs on all control and data pins (WEN, REN, MRS, PRS, D0–D35, etc.), allowing direct interfacing with 5-V TTL or CMOS logic while operating from a 3.3-V supply. This eliminates the need for external level-shifting circuitry in mixed-voltage system designs, reducing BOM cost and board area.

How is bus-width matching configured on the SN74V3660-6PEU?

Bus-width matching on the SN74V3660-6PEU is configured at master reset using the BM (bus matching), IW (input width), and OW (output width) pins. These three inputs select one of five configurations: ×36→×36, ×36→×18, ×36→×9, ×18→×36, or ×9→×36. The setting is latched during MRS and remains active until the next master reset - no runtime reconfiguration is supported.

What is the difference between standard mode and FWFT mode on the SN74V3660-6PEU?

In standard mode, the first word written to an empty SN74V3660-6PEU does not appear on Qn until a read operation (REN + RCLK) is performed. In FWFT mode, the first word appears on Qn after three RCLK rising edges without requiring REN - reducing initial access latency. Mode selection is made at master reset via the FWFT/SI pin state and remains fixed until next MRS.

Can the SN74V3660-6PEU be used in depth-expansion configurations?

Yes, the SN74V3660-6PEU supports depth expansion via serial chaining in FWFT mode: the Qn outputs of one device connect directly to the Dn inputs of the next, with shared RCLK/WCLK and synchronized flag propagation. No external logic is required. This enables scalable buffering beyond 4096 words - e.g., two SN74V3660-6PEU devices yield 8192 × 36-bit capacity with seamless data flow.