STMicroelectronics 74LX1G125CTR

Overview

74LX1G125CTR from STMicroelectronics is a single 3-state bus buffer IC designed for voltage-level translation and bus isolation in low-power portable systems. It operates across 1.65V–5.5V supply, delivers 4.7ns max propagation delay at 3V, supports 24mA output drive, and features power-down protection enabling 0–7V input tolerance regardless of VCC. It is used in Smart Phone and Digital Still Camera I/O interface circuits.

For engineers reviewing the 74LX1G125CTR datasheet, 74LX1G125CTR pinout, 74LX1G125CTR application, or 74LX1G125CTR equivalent, key selection criteria include 3-state enable timing (tPLZ/tPZL ≤ 6.0ns), symmetrical output drive (|IOH| = IOL ≥ 24mA @ 3V), wide VCC range (1.65–5.5V), input overvoltage tolerance (0–7V), and ultra-low ICC (≤1µA).

Technical Context

This CMOS buffer implements a single non-inverting data path with active-high 3-state control (1G). Its sub-micron C2MOS process enables operation down to 1.65V while retaining 5V-tolerant inputs - critical for mixed-voltage interconnects between legacy 5V logic and modern 1.8V/2.5V subsystems.

The device guarantees balanced tPLH ≅ tPHL propagation delays and includes integrated ESD protection on all pins. Power-down protection ensures safe I/O behavior during VCC = 0V conditions, allowing hot insertion and partial power-down without latch-up risk (≥300mA Latch-up rating).

Key Specifications

Pinout & Package

SOT323-5L package: 1.3mm × 1.3mm × 0.9mm body, 5-pin surface-mount, lead-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G125DBVR and NC7SZ125P5X, the 74LX1G125CTR uniquely combines 7V input tolerance, 1.65–5.5V operation, and sub-1µA ICC - making it the only option for robust, ultra-low-power level translation in portable equipment with unpredictable power sequencing.

Availability

74LX1G125CTR is available at Aetrix Electronics and suitable for smartphone baseband interfaces, digital still camera sensor buses, and notebook PCH expansion requiring stable component supply across extended temperature and mixed-voltage conditions.

Supply support for 74LX1G125CTR 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, Switzerland, specializing in microcontrollers, power management, analog, and MEMS technologies for automotive, industrial, and consumer markets.

The 74LX series targets ultra-low-power, mixed-voltage interface applications in battery-powered portable electronics - emphasizing voltage translation, bus isolation, and power-aware I/O control without performance compromise.

FAQ

Can 74LX1G125CTR operate with VCC = 1.65V while accepting 5V input signals?

Yes. The device guarantees full functionality at VCC = 1.65V and supports DC input voltages up to 7V regardless of supply level. This is enabled by internal power-down protection circuitry that isolates inputs from the core logic when VCC is low or absent - a feature confirmed in the Absolute Maximum Ratings and Recommended Operating Conditions tables.

What is the maximum capacitive load this buffer can drive at 3V supply while maintaining 4.7ns tPD?

At VCC = 3V, the 4.7ns max tPD is specified with CL = 15pF and RL = 500Ω. With CL = 50pF, propagation delay increases to 5.2ns (max) under identical conditions. Driving heavier loads requires derating timing or adding series termination to maintain signal integrity - no internal driver boost is provided beyond the rated 24mA sink/source capability.

Does 74LX1G125CTR support hot-plug operation when VCC is off?

Yes. When VCC = 0V, the device permits input voltages from 0V to 5.5V (per VO specification) and limits input/output leakage to ±10µA (IOZ and Ioff specs). This enables safe connection/disconnection of live signals during system maintenance or modular expansion - a capability verified in the DC specifications and absolute maximum ratings sections.

How does the 74LX1G125CTR differ from standard 74LVC1G125 in terms of ESD robustness?

The 74LX1G125CTR integrates HBM ESD protection >2kV on all pins per manufacturer test data, exceeding the typical 2kV minimum of standard LVC devices. Its C2MOS process and dedicated I/O protection structures eliminate need for external ESD components in handheld product designs - a distinction confirmed in the "All inputs and outputs are equipped with protection circuits against ESD discharge" statement on page 1.