STMicroelectronics 74LX1G05STR

Overview

74LX1G05STR from STMicroelectronics is a single-channel CMOS inverter with open-drain output, designed for level-shifting and current-sinking applications. It operates from 1.65V to 5.5V, delivers 32mA sink current at 5V, achieves 4.2ns max propagation delay at 3V, and supports 5V-tolerant inputs independent of VCC - enabling robust 5V-to-3V interfacing in mixed-voltage systems.

For engineers reviewing the 74LX1G05STR datasheet, 74LX1G05STR pinout, 74LX1G05STR application, or 74LX1G05STR equivalent, key selection criteria include open-drain drive capability, input overvoltage tolerance up to 7V, power-down protection, low ICC (≤1µA), and SOT23-5L package compatibility with space-constrained PCB layouts.

Technical Context

This device implements a three-stage buffered inverter architecture with open-drain output, delivering high noise immunity and stable switching across its 1.65–5.5V operating range. Its input structure accepts voltages from –0.5V to +7.0V regardless of VCC, and includes diode-based ESD protection on all pins.

The output stage is optimized for sinking current only, requiring an external pull-up for logic-high assertion. Power-down protection ensures safe operation during supply sequencing or brownout conditions, with Ioff leakage ≤10µA when VCC = 0V and VI/VO = 5.5V.

Key Specifications

Pinout & Package

SOT23-5L package: 2.80 × 1.50 × 1.30 mm body, 0.95 mm pitch, 5-terminal surface-mount outline with exposed pad not present. Pin 1 is NC (not connected); pin 2 is input; pin 3 is GND; pin 4 is open-drain output; pin 5 is VCC.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single open-drain inverter applications.

Compared with SN74LVC1G05DBVR and NC7SZ05P5X, the 74LX1G05STR uniquely balances 5V input tolerance, 32mA sink capability, and SOT23-5L manufacturability - making it optimal for legacy 5V-system integration where voltage translation and reliability outweigh ultra-low capacitance or minimal footprint.

Availability

74LX1G05STR is available at Aetrix Electronics and suitable for industrial sensor interfaces, I²C bus level shifting, and LED indicator driver applications requiring stable component supply and long-term obsolescence management.

Supply support for 74LX1G05STR 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 automotive, industrial, and power management solutions with vertical manufacturing capabilities.

The 74LX series targets low-voltage, high-speed logic interoperability across mixed-supply systems, emphasizing voltage translation, power-down safety, and robustness in industrial and consumer edge devices.

FAQ

Can 74LX1G05STR be used with VCC = 0V while inputs are at 5V?

Yes - the device features power-down protection with Ioff ≤10µA when VCC = 0V and VI or VO = 5.5V. This prevents back-powering of the supply rail and ensures safe operation during hot-plug or partial power-down scenarios without damaging the IC or corrupting system logic states.

What is the maximum sink current at 1.8V supply?

At VCC = 1.65–2.3V, the guaranteed IOL is +4mA (min) with VOL ≤0.45V. This is sufficient for low-power logic interfacing or weak LED indication but not for high-brightness indicators - design must verify voltage drop across external pull-up and load under worst-case process/temperature corners.

Is pin 1 (NC) electrically isolated or internally tied?

Pin 1 is Not Connected - no internal bond wire, metallization, or circuit node is attached. It is physically isolated per mechanical drawings and must remain unconnected on PCB; soldering or routing to this pin may cause mechanical stress or unintended coupling in high-frequency layouts.

Does the 74LX1G05STR support true bidirectional level shifting?

No - it is a unidirectional inverter with open-drain output. For bidirectional I²C level shifting, two units are required (one per direction) with pull-ups on both sides, or a dedicated bidirectional translator like TXS0102. The device does not auto-detect direction or provide internal pass-gate functionality.