Texas Instruments SN74CBTD3306CPW

Overview

SN74CBTD3306CPW from Texas Instruments is a dual 1-bit high-speed FET bus switch with bidirectional data flow, 3 Ω typical ON-state resistance, −2 V undershoot protection on A/B ports, and integrated 5-V-to-3.3-V level shifting via V_CC-series diode. It operates from 4.5 V to 5.5 V and supports mixed-voltage signaling (0.8 V to 5 V) in USB interface and bus isolation applications.

For engineers reviewing the SN74CBTD3306CPW datasheet, SN74CBTD3306CPW pinout, SN74CBTD3306CPW application, or SN74CBTD3306CPW equivalent, key selection criteria include I_off-enabled partial-power-down operation, 0.15 ns propagation delay, 5 pF OFF-state I/O capacitance, TTL/CMOS-compatible control inputs, and TSSOP-8 package compatibility with industrial temperature range (−40°C to 85°C).

Technical Context

The SN74CBTD3306CPW implements two independent FET-based transmission gates, each controlled by dedicated OE inputs (1OE, 2OE), enabling per-channel ON/OFF state control. Its internal undershoot-protection circuitry actively monitors A/B port voltages and forces switch disable when undershoot exceeds −2 V, preventing false conduction during signal transients.

Level shifting is achieved through an integrated diode between V_CC and the B-port side of each switch, allowing 5-V logic at A to drive 3.3-V–tolerant loads at B without external components. The device supports true bidirectional signal flow with near-zero propagation delay and maintains high-impedance isolation when OE is high or V_CC = 0.

Key Specifications

Pinout & Package

TSSOP-8 package (PW), 3.0 mm × 4.4 mm body, 0.65 mm pitch, 1.2 mm max height, RoHS-compliant NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3306CPW, SN74CBT3306CPW offers identical pinout and speed but omits level shifting, while SN74LVC1G3157DBVR reduces footprint at the cost of channel count, protection features, and power-down safety-making SN74CBTD3306CPW optimal for robust, dual-channel, mixed-voltage bus management.

Availability

SN74CBTD3306CPW is available at Aetrix Electronics and suitable for USB interface design, memory interleaving architectures, and industrial bus isolation requiring stable component supply, long-term lifecycle support, and RoHS-compliant TSSOP packaging.

Supply support for SN74CBTD3306CPW 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 90 years of innovation in high-reliability IC design and manufacturing.

The SN74CBTD3306CPW belongs to TI's 74CBT family of high-speed CMOS bus switches, engineered for low-distortion, low-latency signal routing in mixed-voltage digital systems including computing, communications, and industrial control.

FAQ

What is the maximum undershoot voltage the SN74CBTD3306CPW can withstand on its A and B ports?

The SN74CBTD3306CPW provides active undershoot protection up to −2 V on both A and B ports, as verified in the absolute maximum ratings and undershoot characteristics section of the SCDS128A datasheet. This ensures the switch remains reliably OFF during negative transients, preventing unintended conduction and protecting downstream circuitry without requiring external clamping diodes. The SN74CBTD3306CPW achieves this via internal sensing circuitry that disables the FET gate when undershoot is detected.

Does the SN74CBTD3306CPW support level shifting between 5-V and 3.3-V logic domains?

Yes, the SN74CBTD3306CPW supports unidirectional 5-V-to-3.3-V level shifting via an integrated diode in series with V_CC, as explicitly stated in the device description and functional specifications. When a 5-V signal is applied to the A port, the diode drop reduces the effective voltage seen at the B port to approximately 3.3 V, enabling direct interfacing with 3.3-V–tolerant receivers. The SN74CBTD3306CPW does not support reverse (3.3-V-to-5-V) level shifting, and bidirectional data flow occurs only within the same voltage domain unless externally biased.

What is the typical ON-state resistance (r_on) of the SN74CBTD3306CPW and how does it affect signal integrity?

The SN74CBTD3306CPW has a typical ON-state resistance of 3 Ω at V_CC = 4.5 V, as specified in the electrical characteristics table. This low r_on minimizes voltage drop across the switch (e.g., <38 mV at 12.5 mA), preserves signal amplitude, and reduces resistive heating during sustained current flow. Combined with 5 pF OFF-state capacitance, the SN74CBTD3306CPW maintains high-fidelity signal transmission in high-speed digital and analog-gating applications without introducing measurable distortion or timing skew.

Can the SN74CBTD3306CPW be used in partial-power-down systems?

Yes, the SN74CBTD3306CPW fully supports partial-power-down operation via its I_off feature, which limits leakage current to 10 µA when V_CC = 0 V and I/O voltages range from 0 V to 5.5 V. This prevents damaging backflow current into powered-down sections of a system, enabling safe hot-swap and power-domain sequencing. The SN74CBTD3306CPW maintains high-impedance isolation under these conditions, making it suitable for modular systems where subsystems may be independently powered.

What package type and thermal characteristics apply to the SN74CBTD3306CPW?

The SN74CBTD3306CPW uses the TSSOP-8 (PW) package: 3.0 mm × 4.4 mm body, 0.65 mm lead pitch, 1.2 mm maximum height, with NIPDAU lead finish and MSL Level-1 rating. Its thermal impedance θ_JA is 149°C/W, as documented in the absolute maximum ratings table. This value reflects junction-to-ambient performance under standard JEDEC test conditions and informs thermal design for continuous operation at up to 85°C ambient, especially when driving ≥64 mA per channel.