Texas Instruments SN74CBT3383CDBRE4

Overview

SN74CBT3383CDBRE4 from Texas Instruments is a 10-bit high-speed FET bus-exchange switch with bidirectional data flow, 3 Ω typical ON-state resistance (ron), −2 V undershoot protection on A/B ports, and 0.15 ns propagation delay at 5 V. It operates from 4 V to 5.5 V and supports 0–5 V signaling levels across mixed-voltage systems such as PCI interface and memory interleaving.

For engineers reviewing the SN74CBT3383CDBRE4 datasheet, SN74CBT3383CDBRE4 pinout, SN74CBT3383CDBRE4 application, or SN74CBT3383CDBRE4 equivalent, key selection criteria include Ioff partial-power-down capability, 8 pF OFF-state I/O capacitance, BE/BX dual-control logic for port exchange, and SSOP-24 package compatibility with space-constrained board layouts.

Technical Context

The SN74CBT3383CDBRE4 implements a 5-bit × 2-path bus-exchange architecture controlled by BE (enable) and BX (exchange select). When BE = L, it routes A1↔B1 and A2↔B2; when BX = H, it swaps paths (A1↔B2, A2↔B1). This enables dynamic signal reconfiguration without external logic.

Its FET-based switch design delivers near-zero propagation delay via low ron and minimal Cio(OFF) = 8 pF, while active undershoot-protection circuitry clamps transient excursions to −2 V on both A and B ports-critical for hot-swap and mixed-rail environments where voltage glitches occur during insertion or power sequencing.

Key Specifications

Pinout & Package

SN74CBT3383CDBRE4 is housed in a 24-pin SSOP (Shrink Small Outline Package) with 0.65 mm lead pitch, JEDEC MO-153 compliant, and RoHS/Green certified. The package measures 8.2 mm × 3.95 mm × 1.75 mm (L×W×H) and is rated MSL Level-2 (260°C, 1 year).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3383CDBRE4, SN74CBTD3383CDBR adds 3.3-V control tolerance at the cost of supply separation, while SN74CBT3384CDW trades compact SSOP size for superior thermal performance in SOIC form-neither is pin-compatible, requiring PCB redesign.

Availability

SN74CBT3383CDBRE4 is available at Aetrix Electronics and suitable for PCI interface, memory interleaving, and bus isolation applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74CBT3383CDBRE4 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 over 90 years of innovation in high-reliability IC design.

The SN74CBT3383CDBRE4 belongs to TI's CBT (Crossbar Bus Transceiver) family, engineered for ultra-low-latency, high-fidelity signal routing in mixed-voltage computing and communications infrastructure.

FAQ

What is the maximum undershoot voltage the SN74CBT3383CDBRE4 can withstand on its A and B ports?

The SN74CBT3383CDBRE4 provides active undershoot protection up to −2 V on both A and B ports, verified per datasheet SCDS175. This is achieved via integrated clamp circuitry that senses negative transients and forces the switch into a robust OFF state-ensuring isolation even during hot-plug events or power-rail collapse. The SN74CBT3383CDBRE4 maintains this rating across its full operating temperature range of −40°C to 85°C.

Does the SN74CBT3383CDBRE4 support partial-power-down operation, and how is it implemented?

Yes, the SN74CBT3383CDBRE4 supports partial-power-down via its Ioff feature. When VCC = 0 V, leakage current is limited to 10 µA maximum, preventing damaging backflow from live I/O lines into the unpowered device. This behavior is intrinsic to the FET switch architecture and requires no external components. The SN74CBT3383CDBRE4 remains in high-impedance state during power-off, making it suitable for use in multi-rail systems where subsystems power up/down independently.

What is the typical ON-state resistance (ron) of the SN74CBT3383CDBRE4, and how does it affect signal integrity?

The SN74CBT3383CDBRE4 has a typical ON-state resistance of 3 Ω at VCC = 4.5 V and IO = 30 mA, with a maximum of 6 Ω across operating conditions. This low ron minimizes voltage drop and signal attenuation-critical for maintaining logic thresholds in high-speed buses. For example, at 64 mA drive current, the worst-case drop is under 384 mV, preserving noise margins in 5-V TTL systems. The SN74CBT3383CDBRE4 achieves this without compromising switching speed, delivering <0.25 ns propagation delay.

Can the SN74CBT3383CDBRE4 be used in analog signal paths, and what specifications support that use?

Yes, the SN74CBT3383CDBRE4 is qualified for analog signal gating due to its low 3 Ω ron, symmetrical conduction, and low charge injection (<1 pC typical). Its ON-state capacitance is 18.5 pF and OFF-state capacitance is only 8 pF, minimizing loading and distortion in DC–10 MHz paths. The SN74CBT3383CDBRE4 also exhibits flat frequency response and low THD+N in buffered sensor or reference signal routing-verified in TI application notes for mixed-signal test equipment.

What are the recommended power-up sequencing guidelines for the SN74CBT3383CDBRE4 to ensure reliable high-impedance startup?

To guarantee high-impedance state during power-up, the BE pin of the SN74CBT3383CDBRE4 must be held high via an external pullup resistor to VCC. TI specifies minimum pullup strength based on driver sink capability; a 10-kΩ resistor is commonly sufficient for standard CMOS drivers. Leaving BE floating or uncontrolled risks metastable switching or unintended conduction. The SN74CBT3383CDBRE4 does not include internal pullups, so this external network is mandatory for robust system initialization.