Texas Instruments SN74CBTD3306CPWRG4

Overview

SN74CBTD3306CPWRG4 from Texas Instruments is a dual 1-bit high-speed FET bus switch with bidirectional data flow, 3 Ω typical ON-state resistance (ron), −2 V undershoot protection on A/B ports, and integrated 5-V-to-3.3-V level shifting via VCC diode. It operates from 4.5 V to 5.5 V and supports 0–5 V signaling across 0.8 V to 5 V logic families, used in USB interface and bus isolation applications.

For engineers reviewing the SN74CBTD3306CPWRG4 datasheet, SN74CBTD3306CPWRG4 pinout, SN74CBTD3306CPWRG4 application, or SN74CBTD3306CPWRG4 equivalent, key selection criteria include Ioff partial-power-down support, 0.15 ns propagation delay, TSSOP-8 package compatibility, and ±128 mA switch current handling under 5 V operation.

Technical Context

The SN74CBTD3306CPWRG4 implements two independent FET-based analog switches controlled by separate OE inputs (1OE, 2OE), each enabling bidirectional conduction between A and B terminals when low. Its internal undershoot-protection circuitry actively clamps A/B port voltages down to −2 V while maintaining OFF-state isolation.

Level shifting is achieved through an integrated series diode between VCC and the switch path, allowing 5-V inputs to drive 3.3-V outputs without external components. The device features Ioff functionality for backflow prevention during partial power-down and meets JESD 78 Class II latch-up immunity (>100 mA).

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 SN74CBTD3306CPWRG4, SN74CBT3306CPWR offers identical performance with legacy packaging, while SN74LVC1G3157DBVR trades robustness and dual-channel capability for smaller size and lower voltage operation-making it unsuitable as a drop-in replacement in 5-V or USB-critical designs.

Availability

SN74CBTD3306CPWRG4 is available at Aetrix Electronics and suitable for USB interface design, memory interleaving architectures, and bus isolation systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant TSSOP packaging.

Supply support for SN74CBTD3306CPWRG4 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 technologies, with over 90 years of innovation in high-reliability silicon solutions.

The SN74CBTD3306CPWRG4 belongs to TI's 74CBT family of high-speed CMOS bus switches, engineered for low-distortion signal gating, mixed-voltage domain bridging, and robust transient protection in computing, communications, and industrial control systems.

FAQ

What is the maximum undershoot voltage the SN74CBTD3306CPWRG4 can tolerate on its A and B ports?

The SN74CBTD3306CPWRG4 provides active undershoot protection up to −2 V on both A and B ports, verified per test conditions in the SCDS128A datasheet. This ensures reliable OFF-state isolation during hot-plug transients in USB and peripheral interfaces without latch-up or false logic assertion. The protection circuit senses undershoot events and maintains switch disable state regardless of VCC status.

Does the SN74CBTD3306CPWRG4 support level shifting between 5-V and 3.3-V logic domains?

Yes, the SN74CBTD3306CPWRG4 integrates a diode in series with VCC to enable 5-V input down to 3.3-V output level shifting. When a 5-V signal is applied to the A port with VCC = 5 V, the internal diode drops ~0.7 V, delivering ~4.3 V to the B port - compatible with 3.3-V CMOS thresholds. This eliminates external level-shifter components in mixed-voltage bus architectures.

What is the ON-state resistance (ron) specification for the SN74CBTD3306CPWRG4, and how does it affect signal integrity?

The SN74CBTD3306CPWRG4 has a typical ON-state resistance (ron) of 3 Ω at VCC = 4.5 V, with a maximum of 6 Ω. This low ron minimizes voltage drop and insertion loss across the switch, preserving signal amplitude and edge rate in high-speed digital paths such as USB 1.1 and memory address/data lines. At ±128 mA maximum current, the worst-case IR drop remains under 768 mV, ensuring TTL/CMOS logic threshold margins are maintained.

Can the SN74CBTD3306CPWRG4 be used in partial-power-down applications?

Yes, the SN74CBTD3306CPWRG4 features Ioff support, limiting off-state current to 10 µA when VCC = 0 V. This prevents back-current flow from live I/O lines into unpowered sections of a system, enabling safe partial-power-down operation in modular electronics, PCIe add-in cards, and battery-backed subsystems. The device maintains high-impedance isolation even when VCC is disconnected.

What package type and dimensions does the SN74CBTD3306CPWRG4 use?

The SN74CBTD3306CPWRG4 uses the TSSOP-8 (PW) package: 3.0 mm × 4.4 mm body size, 0.65 mm lead pitch, 1.2 mm maximum height, with 8 gull-wing leads. It complies with JEDEC MO-153 variation AA and is supplied in tape-and-reel format (2000 units/reel), RoHS-compliant with NIPDAU lead finish and MSL Level-1 rating for unlimited floor life at ≤30 °C/60% RH.