STMicroelectronics 74V1T125CTR

Overview

74V1T125CTR from STMicroelectronics is a single 3-state bus buffer IC designed for level-shifting and bidirectional bus isolation in 5V/3V mixed-voltage systems. It features 3.5ns typical propagation delay at 5V, ±8mA symmetrical output drive, and input tolerance up to 7V independent of VCC. It is used in industrial control backplanes and legacy TTL-to-CMOS interface circuits.

For engineers reviewing the 74V1T125CTR datasheet, 74V1T125CTR pinout, 74V1T125CTR application, or 74V1T125CTR equivalent, key selection criteria include 3-state enable timing (tPZL/tPZH ≤ 7.0ns), power-down input protection, and 4.5–5.5V operating range with sub-1µA quiescent current.

Technical Context

This device implements a single-channel CMOS buffer with active-high 3-state enable (1G) controlling output (1Y) high-impedance state. Its C2MOS process enables rail-to-rail input tolerance (0–7V), allowing safe interfacing between 5V logic and 3V subsystems without external clamping.

Propagation delays are balanced (tPLH ≅ tPHL), and output impedance is symmetrical (|IOH| = IOL ≥ 8mA at VCC = 4.5V). The input structure includes diode-based power-down protection, permitting valid logic levels even when VCC is unpowered.

Key Specifications

Pinout & Package

SOT323-5L package: 1.35mm × 2.1mm body, 0.65mm pitch, 5-terminal surface-mount with exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G125DBVR and 74AHC1G125W5-7, the 74V1T125CTR uniquely delivers 7V input tolerance with zero-VCC operation support-critical for field-replaceable module interfaces-while maintaining 3.5ns speed and sub-µA quiescence in industrial environments.

Availability

74V1T125CTR is available at Aetrix Electronics and suitable for industrial backplane interface, legacy system voltage translation, and power-sensitive remote monitoring node applications requiring stable component supply and long-term lifecycle assurance.

Supply support for 74V1T125CTR 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 analog, MCU, power, and automotive ICs with emphasis on industrial and automotive reliability.

The 74V series targets high-speed, low-power CMOS logic for industrial and telecom infrastructure, emphasizing robustness across extended temperature ranges and mixed-voltage interoperability.

FAQ

Can the 74V1T125CTR operate with VCC = 0V while inputs are active?

Yes. Its input protection architecture allows inputs to accept 0–7V signals even when VCC = 0V, enabling safe hot-plug operation and power sequencing independence. This is explicitly guaranteed in the Absolute Maximum Ratings and Recommended Operating Conditions tables.

What is the maximum capacitive load this buffer can drive reliably?

The AC Electrical Characteristics specify timing performance up to CL = 50pF. With 8mA output drive and 5pF typical COUT, it reliably drives ≥10 standard CMOS inputs (each ~5pF) or a 50Ω transmission line terminated at 5V, maintaining ≤7ns propagation delay variation across temperature.

Does the 74V1T125CTR support bidirectional data flow?

No. It is a unidirectional buffer: signal flows only from pin 2 (1A) to pin 4 (1Y). Bidirectional operation requires external control logic or a dedicated transceiver like the 74V1T126 (inverting) or 74V1T245 (octal).

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

Yes. Per STMicroelectronics' packaging documentation, the SOT323-5L variant of the 74V1T125CTR uses lead-free terminations and complies with RoHS Directive 2011/65/EU, with homogeneous material analysis confirming Pb content < 0.1% by weight.