Texas Instruments 74CB3T1G125DBVRE4

Overview

74CB3T1G125DBVRE4 from Texas Instruments is a single-channel FET bus switch IC designed for bidirectional level translation and bus isolation in mixed-voltage systems. It operates from 2.3 V to 3.6 V, supports 5-V-tolerant I/Os, delivers typ. 5 Ω ON-state resistance, <0.25 ns propagation delay, and enables partial-power-down via Ioff. It is used in USB interface signal routing and low-power portable equipment.

For engineers reviewing the 74CB3T1G125DBVRE4 datasheet, 74CB3T1G125DBVRE4 pinout, 74CB3T1G125DBVRE4 application, or 74CB3T1G125DBVRE4 equivalent, key selection criteria include VCC range (2.3–3.6 V), 5-V-tolerant I/O capability, Ioff support for power sequencing, low capacitance (5 pF OFF-state), and SOT-23 (DBV) 5-pin package compatibility with space-constrained PCB layouts.

Technical Context

The 74CB3T1G125DBVRE4 implements a single NMOS FET-based transmission gate architecture with gate drive referenced to VCC, enabling voltage translation where output tracks VCC. Its control logic uses active-low OE to enable bidirectional conduction between A and B ports.

It features integrated undershoot clamp diodes on all I/Os, supports mixed-mode signaling (0–5 V inputs with 2.5/3.3 V VCC), and guarantees latch-up immunity per JESD 17 (>250 mA). The device maintains high-impedance isolation when OE is high or VCC = 0 V, satisfying Ioff requirements for hot-plug and partial-power-down systems.

Key Specifications

Pinout & Package

SOT-23 (DBV) 5-pin plastic package, 1.45 mm max height, JEDEC MO-178 compliant, tape-and-reel (3000 pcs/reel), 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 SN74CB3T1G125DBVR, 74CB3T1G125DBVRE4 offers identical performance with standardized packaging documentation; versus SN74CB3T1G125DCKR, it provides lower thermal resistance and easier hand-soldering due to larger pitch and taller profile - critical for industrial rework and thermal reliability.

Availability

74CB3T1G125DBVRE4 is available at Aetrix Electronics and suitable for USB interface isolation, microcontroller GPIO expansion, and low-power portable equipment requiring stable component supply across extended product lifecycles.

Supply support for 74CB3T1G125DBVRE4 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 components.

The SN74CB3T1G125 family is designed for low-voltage, high-speed digital interface applications requiring level translation, bus isolation, and partial-power-down capability in space- and power-constrained systems.

FAQ

What is the maximum operating temperature range for the 74CB3T1G125DBVRE4?

The 74CB3T1G125DBVRE4 is rated for operation from –40°C to +85°C ambient temperature. This range is validated per TI's recommended operating conditions and applies to all electrical specifications including ron, tpd, and Ioff. Thermal derating is not required within this range, and the device maintains full functionality across the entire span without parameter drift beyond datasheet limits.

Does the 74CB3T1G125DBVRE4 support true bidirectional signal flow?

Yes, the 74CB3T1G125DBVRE4 supports fully bidirectional data flow between its A and B ports when OE is low. Its FET-based architecture has no intrinsic directionality - signal propagation delay, ON-resistance, and voltage translation behavior are symmetric regardless of whether data originates at A or B. This is confirmed in the functional table and simplified schematic in the official datasheet.

Can the 74CB3T1G125DBVRE4 be used with a 2.5-V VCC to translate 5-V inputs to 2.5-V outputs?

Yes, the 74CB3T1G125DBVRE4 supports 5-V-to-2.5-V level shifting when VCC = 2.5 V. Per Figure 1 and the "Data I/Os Support 0- to 5-V Signaling Levels" specification, VOH tracks VCC, so a 5-V input produces a ~2.5-V output. This is verified across the full operating range (2.3–3.6 V) and is explicitly supported for 2.5-V CMOS systems.

Is the 74CB3T1G125DBVRE4 pin-compatible with other members of the SN74CB3T1G125 family?

Yes, the 74CB3T1G125DBVRE4 shares identical pinout and function with SN74CB3T1G125DBVR and SN74CB3T1G125DCKR - all have 5-pin configurations with VCC, A, GND, B, and OE in the same order for DBV (SOT-23). However, DBV and DCK packages are physically incompatible due to differing lead pitch and body dimensions, so PCB layout must match the specific package variant.

What is the purpose of the Ioff feature in the 74CB3T1G125DBVRE4?

The Ioff feature in the 74CB3T1G125DBVRE4 ensures that leakage current remains below 10 µA when VCC = 0 V, preventing damaging backflow through the switch during partial-power-down states. This allows safe isolation of unpowered subsystems (e.g., a dormant sensor interface) while other sections of the system remain active - a requirement for modern low-power and hot-plug architectures.