STMicroelectronics 74LX1G70STR

Overview

74LX1G70STR from STMicroelectronics is a single high-speed CMOS buffer with 5V-tolerant inputs, operating from 1.65 V to 5.5 V supply, delivering 4.2 ns max propagation delay at 3 V, ±24 mA output drive, and 1 µA max quiescent current - used for level-shifting and signal conditioning in mixed-voltage I/O interfaces.

For engineers reviewing the 74LX1G70STR datasheet, 74LX1G70STR pinout, 74LX1G70STR application, or 74LX1G70STR equivalent, key selection criteria include input voltage tolerance (0–7 V), symmetrical output drive strength, power-down protection, latch-up immunity, and SOT23-5L package compatibility in space-constrained 3.3/5 V system interconnects.

Technical Context

This device implements a three-stage buffered architecture with dedicated output stage for stable drive and high noise immunity. Its input structure accepts 0–7 V regardless of VCC, enabling safe interfacing between 3.3 V logic and legacy 5 V buses without external clamping.

The internal design enforces balanced tPLH ≈ tPHL propagation delays and includes diode-based ESD protection on all pins plus 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: 2.80 × 1.50 × 1.30 mm body, 0.95 mm pin pitch, surface-mount, lead-free, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC1G125DBVR and NC7SZ17P5X, the 74LX1G70STR uniquely combines true 0–7 V input tolerance at any VCC ≥1.65 V, power-down isolation, and symmetrical drive - making it optimal for mixed-voltage industrial and automotive interconnects where reliability under supply variation is critical.

Availability

74LX1G70STR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, automotive body control modules, and medical wearable sensor hubs requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for 74LX1G70STR 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, designing and manufacturing silicon solutions for automotive, industrial, and power management applications.

The 74LX series targets low-voltage, high-speed logic interoperability in mixed-supply systems - specifically engineered for robust 1.65–5.5 V operation with enhanced ESD and latch-up resilience in harsh environments.

FAQ

Can 74LX1G70STR be used with VCC = 1.8 V while interfacing to a 5 V microcontroller output?

Yes. The device accepts 0–7 V on input pin 1A regardless of VCC, including at 1.8 V supply. Input thresholds scale with VCC (VIH = 0.7×VCC min), ensuring reliable logic detection. Output swing remains rail-to-rail (VOH ≥ VCC − 0.1 V), compatible with 1.8 V receivers.

Does 74LX1G70STR require external pull-up or pull-down resistors on unused pins?

No. Pin 1 is internally unconnected (NC) and must be left floating or tied to GND per layout guidelines; no pull resistors needed. Inputs and outputs have built-in ESD protection and do not float to undefined states - external biasing is unnecessary unless specific noise immunity is required in extreme EMI environments.

What is the maximum operating frequency supported by 74LX1G70STR in a 50 pF load configuration?

With CL = 50 pF and VCC = 3.0 V, tPD(max) = 4.2 ns yields a theoretical maximum toggle rate of ~119 MHz. Real-world usable frequency is ~80 MHz due to board trace capacitance and signal integrity constraints. For >100 MHz applications, verify setup/hold margins using IBIS models in your PCB simulation tool.

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

When VCC = 0 V, internal protection circuitry places both input (1A) and output (1Y) terminals in high-impedance state with ≤10 µA leakage. This prevents back-powering of the supply rail or loading of upstream drivers - essential for hot-plug modules and partial-system power gating in modular industrial controllers.