Texas Instruments SN74V3650-10PEU

Overview

SN74V3650 from Texas Instruments is a 2048 × 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 read/write cycle time), 5-V-tolerant inputs, and zero-latency retransmit capability - deployed in high-speed network buffering, video frame synchronization, and telecom data bridging applications.

For engineers reviewing the SN74V3650 datasheet, SN74V3650 pinout, SN74V3650 application, or SN74V3650 equivalent, key selection criteria include its 2048-depth ×36-width configuration, FWFT vs. standard mode behavior, programmable almost-empty/almost-full flag offsets, dual-clock domain operation, and 128-pin TQFP package compatibility with depth/width expansion requirements.

Technical Context

This FIFO implements a dual-port, clocked RAM architecture with separate WCLK/RCLK domains enabling simultaneous read/write at up to 166 MHz. Its control logic supports master reset (MRS) and partial reset (PRS), configurable flag timing (synchronous/asynchronous PAF/PAE), and retransmit latency selection (RM pin).

Bus-matching is determined at master reset via BM/IW/OW pins, enabling five input/output width combinations (e.g., ×36 in → ×18 out). Big-endian/little-endian byte ordering (BE), interspersed parity (IP), and serial/parallel flag programming (LD/FSEL0/FSEL1/SEN) are all configured during initialization and retained across PRS.

Key Specifications

Pinout & Package

SN74V3650 is housed in a 128-pin Thin Quad Flat Pack (TQFP) with 0.4-mm lead pitch, JEDEC MO-152AC compliant, and thermally optimized for surface-mount reflow assembly.

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 combines 2048-depth buffering, zero-latency retransmit, and full bus-matching configurability - making it optimal for high-fidelity data capture and multi-standard interface bridging where timing determinism and flexibility are mandatory.

Availability

SN74V3650 is available at Aetrix Electronics and suitable for network packet buffering, video frame synchronization, telecom line card bridging, high-speed test equipment data capture, and industrial protocol gateway applications requiring stable component supply across 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 solutions, with decades of leadership in high-speed interface and memory products.

SN74V3650 belongs to TI's high-performance FIFO memory family designed for deterministic, low-latency data buffering in multi-clock-domain systems - targeting telecom infrastructure, broadcast video, and automated test equipment.

FAQ

What is the memory depth and width of the SN74V3650?

The SN74V3650 provides exactly 2048 words of storage, each 36 bits wide - totaling 73,728 bits (72 kbit) of synchronous FIFO memory. This depth is fixed per device variant and distinct from SN74V3640 (1024 × 36) and SN74V3660 (4096 × 36) in the same family. The SN74V3650 does not support dynamic depth adjustment; expansion is achieved via cascading multiple SN74V3650 devices.

Does the SN74V3650 support both FWFT and standard timing modes?

Yes, the SN74V3650 supports both timing modes. The FWFT or standard 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 on Q0–Q35 after three RCLK rising edges without requiring REN assertion. In standard mode, all reads - including the first word - require REN = low. The SN74V3650 maintains this mode setting until next MRS.

How is bus width configured on the SN74V3650?

Bus width is configured using three dedicated pins - BM (bus matching), IW (input width), and OW (output width) - sampled only during master reset. These pins select one of five combinations: ×36 in → ×36 out, ×36 in → ×18 out, ×36 in → ×9 out, ×18 in → ×36 out, or ×9 in → ×36 out. Unused Dn or Qn pins enter don't-care states and must be left unconnected or tied to GND/VCC per design rules - the SN74V3650 does not auto-detect bus width.

Can the SN74V3650 perform zero-latency retransmit?

Yes, zero-latency retransmit is supported on the SN74V3650 when the RM (retransmit latency mode) pin is held low during master reset. In this mode, asserting RT low on a rising RCLK edge causes the first retransmitted word to appear on Q0–Q35 at that same RCLK edge - no additional clock cycles are required. This behavior is confirmed in the SCAS668A datasheet Figures 13–14 and applies identically in both FWFT and standard timing modes.

What is the purpose of the BE (big-endian/little-endian) pin on the SN74V3650?

The BE pin configures byte ordering for multi-word transfers during bus-matching operations - e.g., when writing 36-bit data and reading 18-bit chunks. When BE = low at master reset, big-endian mode is selected: MSB-aligned words are read first. When BE = high, little-endian mode is selected: LSB-aligned words are read first. This setting affects only data interpretation during width conversion and has no impact on single-width (×36→×36) operation. The SN74V3650 retains the BE setting across partial resets (PRS).