Texas Instruments SN74CBT3383DGVR

Overview

SN74CBT3383 from Texas Instruments is a 10-bit TTL-compatible bus-exchange switch operating at 4.5 V–5.5 V, featuring bidirectional signal flow with near-zero propagation delay (tpd ≤ 1 ns), 5 Ω typical on-state resistance (rON), and 200 MHz bandwidth-used for byte-swapping in enterprise server backplanes and Ethernet switch fabric interconnects.

For engineers reviewing the SN74CBT3383 datasheet, SN74CBT3383 pinout, SN74CBT3383 application, or SN74CBT3383 equivalent, key selection criteria include its dual-mode operation (bus switch vs. 5-bit nibble exchanger), low 6 pF off-state I/O capacitance, TTL/3.3-V CMOS control compatibility, and 128 mA per-channel current rating in high-speed data path designs.

Technical Context

The SN74CBT3383 implements a CMOS transmission-gate architecture enabling true bidirectional signal routing without direction pins. Its BE (active-low enable) and BX (bus exchange select) inputs configure it as either a 10-bit transparent bus switch (BE = L, BX = L) or a 5-bit A/B pair exchanger (BE = L, BX = H), swapping 1A1↔1B2, 1A2↔1B1, etc., with no added logic delay.

It operates strictly in the 4.5 V–5.5 V VCC range and delivers flat rON across input voltage (0–5 V) and temperature (0°C–70°C). The device exhibits 6 pF off-state I/O capacitance and 50 µA max ICC, making it suitable for low-noise, high-fanout, hot-swap-capable backplane switching where ground bounce and timing skew must be minimized.

Key Specifications

Pinout & Package

SN74CBT3383DGVR uses a 24-pin TSSOP package (7.80 mm × 4.40 mm body, 1.2 mm max height) with gull-wing leads and pin 1 index area marked per JEDEC MO-153.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus-switching applications.

Compared with SN74CBT3383DGVR, SN74CBTD3383PWR adds voltage translation at the cost of layout complexity and power overhead, while PI3CHD3245LEX trades bus-exchange flexibility for higher bandwidth and lower rON in narrower 8-bit applications.

Availability

SN74CBT3383DGVR is available at Aetrix Electronics and suitable for enterprise servers, Ethernet switches, and industrial PCs requiring stable component supply with guaranteed long-term manufacturability and RoHS-compliant packaging.

Supply support for SN74CBT3383DGVR 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 connectivity solutions, with decades of heritage in high-reliability logic and interface ICs.

The SN74CBT3383 belongs to TI's CBT (Crosspoint Bus Transceiver) family, designed specifically for low-latency, high-fanout bus switching in networking, computing, and telecom infrastructure where deterministic timing and signal integrity are non-negotiable.

FAQ

What is the function of the BX pin on the SN74CBT3383DGVR?

The BX pin on the SN74CBT3383DGVR is the bus-exchange select input. When BX is high and BE is low, it swaps signal pairs-e.g., 1A1 connects to 1B2 and 1A2 connects to 1B1-enabling byte-level reordering without external logic. This function is absent when BX is low, reverting to standard 10-bit bus switching. The SN74CBT3383DGVR relies on this pin to implement nibble-swap capability in server backplane and switch fabric applications.

Can the SN74CBT3383DGVR operate with a 3.3-V control signal?

Yes, the SN74CBT3383DGVR accepts 3.3-V CMOS-level control inputs: VIH is specified at 2.0 V minimum and VIL at 0.8 V maximum, ensuring reliable recognition of 3.3-V logic highs and lows. Its BE and BX inputs are TTL- and CMOS-compatible, allowing direct connection to 3.3-V FPGAs or microcontrollers without level shifters. This interoperability is confirmed in the SN74CBT3383 datasheet Section 6.3 (Recommended Operating Conditions) and applies directly to the SN74CBT3383DGVR variant.

What is the maximum continuous current per channel for the SN74CBT3383DGVR?

The SN74CBT3383DGVR supports a maximum continuous channel current of 128 mA, as specified in Section 6.1 (Absolute Maximum Ratings) of its datasheet. This rating applies to each of its ten bidirectional I/O channels (e.g., 1A1/1B1 pair) under recommended operating conditions (VCC = 4.5 V–5.5 V, TA = 0°C–70°C). Exceeding this limit risks thermal overstress or parametric shift; the SN74CBT3383DGVR must be used within this bound in applications such as server memory buffer switching or Ethernet PHY multiplexing.

Does the SN74CBT3383DGVR require external decoupling capacitors?

Yes, the SN74CBT3383DGVR requires a 0.1-μF ceramic decoupling capacitor placed as close as possible to the VCC pin (pin 24) to suppress high-frequency supply noise and prevent switching-induced ground bounce. TI's datasheet Section 10 explicitly mandates this, noting that inadequate decoupling degrades signal integrity and may cause timing violations. This requirement is identical across all SN74CBT3383 package variants, including the SN74CBT3383DGVR, and is essential for stable operation at 200 MHz.

Is the SN74CBT3383DGVR pin-compatible with other SN74CBT3383 package variants?

Yes, the SN74CBT3383DGVR (TSSOP-24) shares identical pin numbering, pin functions, and electrical behavior with other SN74CBT3383 variants-including DB (SSOP), DW (SOIC), and PW (TSSOP)-as confirmed in the "Pin Configuration and Functions" section (page 3) of the SCDS003P datasheet. All variants use the same 24-pin layout with BE on pin 1, GND on pin 12, BX on pin 13, and VCC on pin 24. Thus, the SN74CBT3383DGVR can replace other SN74CBT3383 packages on the same PCB footprint, provided mechanical clearance and thermal constraints are met.