STMicroelectronics 74V1T125STR

Overview

74V1T125STR from STMicroelectronics is a high-speed CMOS single bus buffer with 3-state output, designed for level-shifting and bus isolation in 5V systems. It features 3.5ns typical propagation delay at 5V, ±8mA symmetrical drive strength, and operates across 4.5V–5.5V supply range-enabling robust interfacing between 5V logic and mixed-voltage domains such as 3V peripherals.

For engineers reviewing the 74V1T125STR datasheet, 74V1T125STR pinout, 74V1T125STR application, or 74V1T125STR equivalent, key selection criteria include its input tolerance (0–7V independent of VCC), power-down protection, low 1µA quiescent current, and SOT23-5L package compatibility with space-constrained PCB layouts.

Technical Context

This device implements a single-channel non-inverting buffer with active-high 3-state enable (1G). Its C2MOS process enables TTL-compatible input thresholds (VIH ≥ 2V, VIL ≤ 0.8V) while supporting overvoltage-tolerant inputs up to 7V regardless of VCC state.

Propagation delays are balanced (tPLH ≅ tPHL), and output disable/enable times are tightly specified (e.g., tPZH = 4.3–9.0ns at CL=15pF), ensuring predictable timing in bidirectional bus control and hot-swap-capable interfaces.

Key Specifications

Pinout & Package

SOT23-5L package: ultra-compact surface-mount outline (2.8 × 1.5 × 1.1 mm), thermal pad-less, lead-free compatible, optimized for automated placement and reflow.

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 74AHC1G125W5-7, the 74V1T125STR uniquely supports 0–7V input tolerance and power-down protection-making it the only option for fail-safe interfacing with unpowered or floating subsystems in industrial and automotive contexts.

Availability

74V1T125STR is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, and medical diagnostic equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74V1T125STR 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, designing and manufacturing microcontrollers, power management ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The 74V series targets high-speed, low-power logic interfacing in harsh environments, emphasizing robustness, wide supply tolerance, and long-term availability for mission-critical embedded systems.

FAQ

Can the 74V1T125STR safely interface a 5V microcontroller with a 3V sensor without external level shifters?

Yes. Its inputs accept 0–7V regardless of VCC, and its outputs swing rail-to-rail within the 4.5–5.5V supply range. When driven by a 5V MCU, the 1Y output can directly connect to a 3V sensor's input if the sensor tolerates 5V logic-high - otherwise, a series resistor or dedicated level shifter remains necessary for voltage compliance.

What is the maximum capacitive load the 74V1T125STR can drive while maintaining 3.5ns typical propagation delay?

The 3.5ns tPD is specified at CL = 15pF. At CL = 50pF, typical propagation delay increases to 3.8ns. For loads exceeding 50pF, timing margins degrade significantly; use local decoupling and minimize trace length to stay within the 15–50pF design window validated in the datasheet.

Does the 74V1T125STR require external pull-up or pull-down resistors on its 1G (enable) pin?

No. The 1G input has CMOS-compatible thresholds and negligible leakage (±1.0µA max), so it holds its last logic state when floating. However, for deterministic startup behavior, tie 1G to GND via a 10kΩ resistor unless actively driven - preventing unintended output activation during power-up.

Is the SOT23-5L package of the 74V1T125STR compatible with standard pick-and-place equipment and IPC-A-610 Class 2 assembly?

Yes. The SOT23-5L footprint matches JEDEC MO-178AB, with 0.95mm pitch and defined land patterns. Its 2.8×1.5mm body and 0.1–0.6mm lead length meet IPC-A-610 Class 2 mechanical requirements for automated assembly, provided stencil aperture and reflow profile follow STMicroelectronics' recommended guidelines.