STMicroelectronics 74V1T126CTR

Overview

74V1T126CTR from STMicroelectronics is a single-channel 3-state bus buffer IC designed for level-shifting and bidirectional bus isolation in 5V/3V mixed-voltage systems. It features 3.6ns typical propagation delay at 5V, ±8mA symmetrical output drive, and input tolerance up to 7V independent of VCC - enabling safe interfacing between 5V logic and lower-voltage domains in industrial control backplanes.

For engineers reviewing the 74V1T126CTR datasheet, 74V1T126CTR pinout, 74V1T126CTR application, or 74V1T126CTR equivalent, key selection criteria include its 4.5–5.5V operating range, power-down protected inputs, high-impedance enable timing (tPZL/tPHZ ≤ 9.5ns), and SOT323-5L package compatibility with space-constrained PCB layouts.

Technical Context

This device implements a CMOS-based single-buffer architecture with active-low 3-state enable (1G), supporting unidirectional data flow from input (1A) to output (1Y). Its C2MOS sub-micron process enables TTL-compatible input thresholds (VIH ≥ 2V, VIL ≤ 0.8V) while maintaining rail-to-rail input voltage tolerance (0–7V).

The output stage delivers matched high- and low-side drive strength (|IOH| = IOL ≥ 8mA at VCC = 4.5V) and balanced propagation delays (tPLH ≅ tPHL), critical for minimizing skew in synchronous bus environments. Power-down protection ensures no current injection into VCC when inputs exceed supply rails.

Key Specifications

Pinout & Package

SOT323-5L package: 1.35mm × 2.2mm body, 0.65mm pitch, 5-terminal surface-mount outline with exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-channel 3-state buffer applications.

Compared with SN74LVC1G125DBVR and 74AHC1G125GW,125, the 74V1T126CTR uniquely combines 7V input tolerance, 1µA quiescent current, and guaranteed 4.5–5.5V operation - making it the only option qualified for industrial backplane isolation where voltage transients and low-power standby coexist.

Availability

74V1T126CTR is available at Aetrix Electronics and suitable for industrial PLC backplane interfaces, automotive body control modules, medical diagnostic equipment data buses, and test & measurement instrumentation requiring stable component supply across extended temperature ranges (-55°C to +125°C).

Supply support for 74V1T126CTR 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, specializing in automotive, industrial, and power management solutions with vertical manufacturing capabilities.

The 74V series targets high-speed, low-power CMOS logic for mixed-voltage system interfacing - specifically engineered for robustness in harsh environments where voltage transients, wide temperature operation, and long-term supply stability are mandatory.

FAQ

Can the 74V1T126CTR operate with VCC = 4.5V while accepting 5V logic inputs?

Yes. The device is fully specified for VCC = 4.5V to 5.5V and supports input voltages from 0V to 7V regardless of VCC level. At VCC = 4.5V, VIH remains ≥2V and VIL ≤0.8V per datasheet, ensuring reliable TTL-level recognition without external biasing.

What is the maximum capacitive load the 74V1T126CTR can drive while maintaining 3.6ns typical propagation delay?

The 3.6ns tPD (typ) is measured at CL = 15pF. At CL = 50pF, tPD increases to 3.9ns (typ). For designs requiring ≤4ns delay, total load (including trace and probe capacitance) must stay below 50pF; layout practices should minimize stub lengths and avoid unterminated branches.

Does the 74V1T126CTR require external pull-up or pull-down resistors on the 1G (enable) pin?

No. The 1G input has standard CMOS thresholds and no internal pull-up/down. However, in systems where the enable signal may float during power-up, a 10kΩ pull-down resistor is recommended to ensure defined high-impedance state until firmware initializes the control line.

Is the SOT323-5L package of the 74V1T126CTR RoHS-compliant and lead-free?

Yes. Per STMicroelectronics' official documentation (Doc ID 12777 Rev 4), the 74V1T126CTR in SOT323-5L packaging is RoHS-compliant, halogen-free, and features 100% matte tin terminal finish with lead-free solderability verified per J-STD-020.