STMicroelectronics 74LX1G14STR

Overview

74LX1G14STR from STMicroelectronics is a low-voltage CMOS single Schmitt trigger inverter with 5V-tolerant inputs, operating from 1.65 V to 5.5 V supply, delivering 7.5 ns max propagation delay at 3 V, 24 mA min symmetrical output drive, and 1 V typical hysteresis at 4.5 V - used for noise-immune signal conditioning in mixed-voltage I/O interfaces.

For engineers reviewing the 74LX1G14STR datasheet, 74LX1G14STR pinout, 74LX1G14STR application, or 74LX1G14STR equivalent, key selection criteria include input hysteresis voltage (0.37–1.11 V), 5V-tolerant input capability independent of VCC, power-down protection on all pins, and SOT23-5L package compatibility with space-constrained board layouts.

Technical Context

The 74LX1G14STR implements a three-stage buffered Schmitt inverter architecture, providing stable switching thresholds (VT+ = 0.79–3.33 V, VT− = 0.39–2.29 V) and hysteresis (0.37–1.11 V) across its full 1.65–5.5 V operating range. Its input protection accepts 0–7 V regardless of VCC, enabling safe interfacing between 3.3 V logic and legacy 5 V signal domains.

It features symmetrical output impedance (|IOH| = |IOL| ≥ 24 mA at 3 V), balanced propagation delays (tPLH ≅ tPHL), and power-down protection that isolates inputs/outputs when VCC = 0 V - critical for hot-swap and partial-power-down systems.

Key Specifications

Pinout & Package

SOT23-5L package: 5-pin surface-mount, 1.3 mm height, 2.8 × 1.5 mm footprint, lead pitch 0.95 mm, tape-and-reel compatible (TR suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Schmitt inverter applications.

Compared with SN74LVC1G14DBVR and NC7SZ14P5X, the 74LX1G14STR uniquely combines 7 V absolute input tolerance with guaranteed hysteresis across full voltage range and power-down protection - making it optimal for industrial and automotive mixed-voltage signal conditioning where robustness is prioritized over marginal speed gain.

Availability

74LX1G14STR is available at Aetrix Electronics and suitable for industrial sensor interface, automotive body control, and IoT edge node wake-up applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 74LX1G14STR 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 discrete components for industrial, automotive, and consumer markets.

The 74LX series targets low-voltage, high-noise-immunity logic applications - specifically engineered for mixed-supply systems where robust signal integrity, wide VCC range, and 5 V-tolerant I/O are mandatory design requirements.

FAQ

Can the 74LX1G14STR operate with VCC = 1.65 V while accepting a 5 V input signal?

Yes. The device's input structure is designed for 0–7 V operation independent of VCC. At VCC = 1.65 V, the 5 V input is safely clamped internally without damage or logic corruption, and the Schmitt thresholds scale accordingly (VT+ ≈ 0.79 V, VT− ≈ 0.39 V). This enables direct interfacing between ultra-low-power cores and legacy 5 V peripherals.

What is the minimum load capacitance for which the 7.5 ns propagation delay is specified?

The 7.5 ns maximum tPD is specified at VCC = 3 V with CL = 50 pF and RL = 500 Ω. For lighter loads (e.g., CL = 15 pF), propagation delay improves to ≤6.5 ns under identical conditions. The test circuit defines CL using a 50 pF capacitor tied to VCC/2 through a 1 MΩ resistor for high-Z loads.

Does Pin 1 (NC) require any PCB layout consideration?

Pin 1 is internally unconnected and electrically inactive. It may be left floating, grounded, or routed as a keep-out zone - no thermal or electrical impact. However, grounding Pin 1 can improve mechanical stability in high-vibration environments and reduce potential for solder bridging during reflow.

How does power-down protection behave when VCC is disconnected during operation?

When VCC drops to 0 V, both inputs and output enter high-impedance states with leakage <10 µA. Inputs tolerate up to 5.5 V without forward-biasing protection diodes, and the output cannot source/sink current - preventing back-powering of upstream circuitry or latch-up in partially powered systems.