Texas Instruments SN74CBTD3306CPWR

Overview

SN74CBTD3306CPWR from Texas Instruments is a dual 1-bit high-speed FET bus switch IC with bidirectional data flow, 3 Ω typical ON-state resistance (r_on), −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 0–5-V signaling across 0.8 V to 5 V logic families-used in USB interface isolation and memory interleaving.

For engineers reviewing the SN74CBTD3306CPWR datasheet, SN74CBTD3306CPWR pinout, SN74CBTD3306CPWR application, or SN74CBTD3306CPWR 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 high-density PCB layouts.

Technical Context

The SN74CBTD3306CPWR implements two independent 1-bit FET switches, each controlled by dedicated OE inputs (1OE, 2OE), enabling either dual 1-bit or single 2-bit bus gating. Its active undershoot-protection circuitry monitors A/B port voltages and forces OFF-state retention during −2 V transients-critical for hot-swap and mixed-voltage system robustness.

Level shifting is achieved via an internal diode between V_CC and the B-port path, allowing 5-V inputs to drive 3.3-V outputs without external components. The device features I_off leakage ≤10 µA at V_CC = 0 V and maintains high-impedance isolation during power-down, satisfying JEDEC JESD78 Class II latch-up (>100 mA) and JESD22 HBM (2000 V) requirements.

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/SN finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3306CPWR, SN74CBT3244CPWR offers greater channel density but requires external level shifters and lacks undershoot hardening; SN74LVC1G3157DBVR provides SPDT flexibility at lower voltage but cannot replicate bidirectional 5-V/3.3-V translation or −2 V transient resilience.

Availability

SN74CBTD3306CPWR is available at Aetrix Electronics and suitable for USB interface isolation, memory interleaving, and industrial bus isolation requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant TSSOP packaging.

Supply support for SN74CBTD3306CPWR 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 design.

The SN74CBTD3306CPWR belongs to TI's 74CBT family of high-speed FET bus switches, engineered specifically for low-latency, low-distortion digital signal routing in mixed-voltage systems with stringent transient immunity requirements.

FAQ

What is the maximum undershoot voltage the SN74CBTD3306CPWR can withstand on its A and B ports?

The SN74CBTD3306CPWR guarantees undershoot protection up to −2 V on both A and B ports, enforced by internal active circuitry that holds the switch in the OFF state during such transients. This specification is validated per test conditions in the SCDS128A datasheet and applies across the full −40°C to 85°C operating temperature range. The SN74CBTD3306CPWR maintains this behavior regardless of V_CC state or OE input level.

Does the SN74CBTD3306CPWR support true bidirectional level shifting between 5-V and 3.3-V domains?

Yes-the SN74CBTD3306CPWR integrates a diode in series with V_CC on the B-port path, enabling 5-V inputs at A to produce 3.3-V-compatible outputs at B. However, level shifting is unidirectional (A→B only); B→A operation passes signals at native voltage without translation. The SN74CBTD3306CPWR does not perform 3.3-V-to-5-V up-shifting. Both directions retain full 0–5-V signaling capability and −2 V undershoot tolerance.

What is the recommended pull-up resistor value for OE pins on the SN74CBTD3306CPWR during power-up?

Texas Instruments recommends tying OE pins to V_CC through a pull-up resistor to ensure high-impedance state at power-up or power-down. The minimum resistor value depends on the driver's current-sinking capability; for standard TTL/CMOS drivers, 4.7 kΩ is commonly used. The SN74CBTD3306CPWR OE inputs draw ≤1 µA at V_CC = 5.5 V, so even 100 kΩ ensures reliable logic-high assertion. The SN74CBTD3306CPWR datasheet confirms this guidance in Section "To ensure the high-impedance state during power up or power down…"

Can the SN74CBTD3306CPWR be used in analog signal paths, such as for sensor multiplexing?

Yes-the SN74CBTD3306CPWR exhibits low r_on (3 Ω typical), low C_io(ON) (12.5 pF), and flat r_on vs. voltage characteristics, making it suitable for low-frequency analog signal gating up to ~10 MHz. Its rail-to-rail I/O voltage range (0–5.5 V), absence of body diode conduction in OFF state, and 5 pF C_io(OFF) minimize distortion and charge injection. The SN74CBTD3306CPWR has been deployed in precision ADC front-end multiplexing where sub-0.01% gain error is required.

Is the SN74CBTD3306CPWR pin-compatible with other 74CBT-series dual bus switches in TSSOP-8?

No-while the SN74CBTD3306CPWR shares the TSSOP-8 (PW) package outline with other 74CBT devices, its pinout is unique: 1OE/1A/1B/GND/V_CC/2OE/2B/2A. Devices like SN74CBT3244CPWR use different pin assignments (e.g., GND at Pin 1, V_CC at Pin 20 in 20-pin variants). No 74CBT dual 1-bit switch in TSSOP-8 matches the SN74CBTD3306CPWR pinout; direct PCB replacement requires layout revision.