Texas Instruments 74CB3T1G125DCKRG4

Overview

74CB3T1G125DCKRG4 from Texas Instruments is a single-bit 5-V-tolerant FET bus switch with bidirectional signal flow, 5 Ω typical ON-state resistance (ron), 0.25 ns typical propagation delay, and VCC operating range of 2.3 V to 3.6 V - used for level translation between 5-V/3.3-V/2.5-V domains in USB interface and bus isolation circuits.

For engineers reviewing the 74CB3T1G125DCKRG4 datasheet, 74CB3T1G125DCKRG4 pinout, 74CB3T1G125DCKRG4 application, or 74CB3T1G125DCKRG4 equivalent, key selection criteria include Ioff partial-power-down support, 5-V-tolerant I/Os with device powered up or down, mixed-mode voltage translation tracking VCC, and SC-70 (DCK) 5-pin package compatibility with space-constrained portable designs.

Technical Context

This device implements a single-channel FET-based analog switch architecture with gate control derived from VCC and input logic, enabling true bidirectional data flow without direction pins. Its ON-state resistance is voltage-dependent and tracks VCC, ensuring consistent signal integrity across 2.3–3.6 V supply operation.

The control logic uses TTL/CMOS-compatible OE input referenced to VCC, with VIH/VIL thresholds scaling with VCC (e.g., VIH ≥ 2.0 V at VCC = 2.7–3.6 V). Ioff protection activates when VCC = 0 V, blocking backflow current up to ±5.5 V on I/O pins - critical for hot-swap and partial-power-down system architectures.

Key Specifications

Pinout & Package

74CB3T1G125DCKRG4 is housed in a 5-pin SC-70 (DCK) surface-mount package measuring 2.15 mm × 1.40 mm × 1.10 mm (max height), optimized for high-density PCB layouts in portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CB3T1G125DCKR, the 74CB3T1G125DCKRG4 offers identical switching performance but enhanced process traceability; versus SN74LVC1G125DBVR, it provides indispensable 5-V tolerance, Ioff, and sub-5-Ω ron - making it irreplaceable in cross-voltage isolation roles.

Availability

74CB3T1G125DCKRG4 is available at Aetrix Electronics and suitable for USB interface isolation, processor-peripheral level translation, and hot-swappable module interconnect requiring stable component supply, long-term lifecycle assurance, and automotive-grade reliability validation.

Supply support for 74CB3T1G125DCKRG4 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 delivering analog, embedded processing, and connectivity solutions with emphasis on reliability, energy efficiency, and system integration.

The SN74CB3T1G125 product line targets low-voltage, high-speed digital interface challenges - specifically engineered for voltage translation, bus isolation, and partial-power-down safety in portable, industrial, and communications equipment.

FAQ

What is the maximum allowable input voltage on the A and B pins of the 74CB3T1G125DCKRG4?

The 74CB3T1G125DCKRG4 supports a VI/O range of –0.5 V to 7 V absolute maximum, with recommended operation from 0 V to 5.5 V. This 5-V-tolerant capability allows direct connection of 5-V signals even when VCC is at 2.5 V or 3.3 V - a core feature confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables of the TI datasheet SCDS150A.

Does the 74CB3T1G125DCKRG4 support partial-power-down operation, and how is it implemented?

Yes, the 74CB3T1G125DCKRG4 implements Ioff partial-power-down protection. When VCC = 0 V, Ioff limits current flow through the A and B pins to ≤10 µA even with voltages up to 5.5 V applied - preventing backfeed and ensuring system-level safety during power sequencing. This behavior is explicitly characterized in the Electrical Characteristics table under the Ioff parameter.

What is the typical ON-state resistance (ron) of the 74CB3T1G125DCKRG4, and how does it vary with VCC?

The 74CB3T1G125DCKRG4 has a typical ON-state resistance of 5 Ω, measured at VCC = 2.5 V and VCC = 3.3 V with IO = 16–32 mA. The datasheet confirms ron remains stable across the full 2.3–3.6 V VCC range, with values ranging from 5–8 Ω depending on current and VCC - enabling predictable voltage drop and signal integrity in precision level-shifting applications.

Can the 74CB3T1G125DCKRG4 be used for bidirectional level translation between 5-V and 2.5-V logic domains?

Yes, the 74CB3T1G125DCKRG4 is explicitly designed for bidirectional level translation: with VCC = 2.5 V, it accepts 0–5.5 V inputs on A or B and outputs ≈VCC − 1 V (≥1.5 V) - satisfying 2.5-V logic high thresholds. Figure 1 and the "5-V/3.3-V Input Down to 2.5-V Output Level" bullet in the Features section confirm this capability for both directions.

What is the thermal resistance (θJA) of the 74CB3T1G125DCKRG4 in its SC-70 (DCK) package?

The 74CB3T1G125DCKRG4 in the SC-70 (DCK) package has a specified junction-to-ambient thermal resistance (θJA) of 252 °C/W, as documented in the Absolute Maximum Ratings table. This value assumes standard JEDEC test conditions (1s pulse, 2-layer board) and is critical for thermal design margining in compact, sealed enclosures.