Texas Instruments SN74CBTD3861PWG4

Overview

SN74CBTD3861PWG4 from Texas Instruments is a 10-bit FET bus switch with integrated level-shifting capability, designed for bidirectional 5-V-to-3.3-V signal translation in high-speed digital systems. It features 5-Ω on-state resistance, TTL-compatible control inputs, and a single OE pin enabling/disabling all ten channels simultaneously. Used in memory expansion interfaces and mixed-voltage processor interconnects.

For engineers reviewing the SN74CBTD3861PWG4 datasheet, SN74CBTD3861PWG4 pinout, SN74CBTD3861PWG4 application, or SN74CBTD3861PWG4 equivalent, key selection criteria include its 0.35 ns propagation delay, ±1 µA ICC, 5–7 Ω on-resistance at 4.5 V, and TSSOP-24 package compatibility with 3.3-V/5-V domain bridging requirements.

Technical Context

This device implements a single 10-bit analog switch array using NMOS FETs with integrated diode-based level-shifting from 5-V inputs to 3.3-V outputs. The OE-controlled switching architecture provides rail-to-rail conduction when enabled and true high-impedance isolation when disabled.

It operates within 4.5 V to 5.5 V supply range, supports –0.5 V to 7 V input voltage tolerance, and delivers sub-nanosecond propagation delay (tpd = 0.35 ns typical) due to low on-resistance and optimized gate drive. No internal logic or latching is present - it functions purely as a passive, voltage-controlled transmission gate array.

Key Specifications

Pinout & Package

TSSOP-24 package (PW), 7.9 mm × 4.4 mm × 1.2 mm body height, lead pitch 0.65 mm, exposed pad not present, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD3861PWG4, SN74CBT3861PW offers identical performance in a functionally interchangeable package, whereas SN74LVC1G3157DCKR requires board-level redesign to achieve even partial functional coverage due to its single-channel architecture and lack of voltage translation.

Availability

SN74CBTD3861PWG4 is available at Aetrix Electronics and suitable for memory expansion interfaces, processor bus isolation, PCI/ISA legacy bridges, and industrial I/O modules requiring stable component supply across extended product lifecycles.

Supply support for SN74CBTD3861PWG4 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 decades of experience in high-reliability logic and interface solutions.

The SN74CBTD3861 belongs to TI's CBTD-series bus switch family, engineered specifically for voltage-domain bridging in mixed-supply digital systems where low-latency, low-distortion signal routing is critical.

FAQ

What is the maximum operating temperature range for the SN74CBTD3861PWG4?

The SN74CBTD3861PWG4 is rated for operation from –40°C to +85°C ambient temperature. This industrial-grade range ensures reliable performance in embedded control systems, factory automation equipment, and outdoor communications hardware where thermal cycling occurs. All electrical specifications in the datasheet are guaranteed across this full range.

Does the SN74CBTD3861PWG4 support bidirectional signal flow?

Yes, the SN74CBTD3861PWG4 supports fully bidirectional signal flow between A and B ports when OE is low. Its FET-based architecture imposes no directionality - signals pass equally well from A-to-B or B-to-A. This enables use in shared data buses like SRAM or Flash interfaces where read and write paths traverse the same physical lines.

Can the SN74CBTD3861PWG4 be used without level shifting?

Yes, the SN74CBTD3861PWG4 functions as a standard 10-bit bus switch even without level shifting. When both A and B sides operate at the same voltage (e.g., 3.3 V or 5 V), the internal diode clamp remains inactive, and the device behaves identically to a pure low-RON analog switch with 0.35 ns propagation delay and 5–7 Ω on-resistance.

What is the recommended decoupling for the VCC pin of the SN74CBTD3861PWG4?

A 0.1 µF ceramic capacitor placed as close as possible to the VCC pin (Pin 13) and GND (Pin 12) is recommended for the SN74CBTD3861PWG4. For systems with high switching activity across multiple channels, adding a 4.7 µF tantalum or X7R MLCC in parallel improves transient response and reduces supply ripple-induced jitter on signal edges.

Is the SN74CBTD3861PWG4 pin-compatible with other packages in the same family?

No - the SN74CBTD3861PWG4 uses the TSSOP-24 (PW) package with 0.65 mm pitch, while other variants like SN74CBTD3861DW use SOIC-24 (4.4 mm pitch) and SN74CBTD3861DBR use SSOP-24 (0.635 mm pitch). Though functionally identical, mechanical incompatibility prevents direct PCB substitution without layout revision.