STMicroelectronics 74LVX257MTR

Overview

74LVX257MTR from STMicroelectronics is a low-voltage CMOS quad 2-channel multiplexer with 3-state outputs and 5V-tolerant inputs, operating from 2V to 3.6V supply. It features symmetrical output drive (±4 mA), 5.8 ns typical propagation delay at 3.3V, and power-down input protection enabling safe 5V-to-3.3V interfacing in battery-powered logic systems.

For engineers reviewing the 74LVX257MTR datasheet, 74LVX257MTR pinout, 74LVX257MTR application, or 74LVX257MTR equivalent, key selection criteria include 5V-tolerant input voltage range (0–7V), high-impedance output enable control, balanced tPLH/tPHL delays, and ESD immunity (2 kV HBM) for mixed-voltage board-level signal routing.

Technical Context

The 74LVX257 implements four independent non-inverting 2:1 multiplexers sharing common SELECT and active-low OE inputs. Each channel selects between A or B inputs based on SELECT logic level and drives a 3-state output only when OE is low.

Its C2MOS sub-micron process enables true 5V-tolerant inputs regardless of VCC, with input diode clamping and power-down protection allowing 0–7V input signals even at VCC = 0V. All I/O pins include 2 kV HBM ESD protection.

Key Specifications

Pinout & Package

SOP-16 (SO-16) package per mechanical drawing 0016020D; 1.27 mm pitch, 10.0 × 3.9 mm body size, tape-and-reel packaging (MTR suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 2:1 multiplexer applications.

Compared with 74LVC257PW and SN74LV4053A, the 74LVX257MTR uniquely combines 5V-tolerant digital inputs, 3.3V-compatible outputs, and sub-6 ns propagation delay-making it optimal for mixed-voltage digital signal routing where interface robustness and speed coexist.

Availability

74LVX257MTR is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, portable instrument data routing, and legacy 5V logic interface applications requiring stable component supply and long-term lifecycle support.

Supply support for 74LVX257MTR 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 ICs with strong analog and mixed-signal design heritage.

The LVX logic family targets low-voltage, low-power, and mixed-voltage digital interfacing applications-designed specifically for battery-operated and noise-sensitive 3.3V systems needing robust 5V signal compatibility.

FAQ

Is 74LVX257MTR pin-compatible with standard 74LS257?

Yes, it is pin- and function-compatible with the 74-series 257 family, including 74LS257 and 74HC257, using identical SOP-16 footprint and truth table. However, its 5V-tolerant inputs and 2–3.6V supply range differ from bipolar or wider-VCC CMOS variants.

Can OE be left unconnected if always enabled?

No-OE must be actively driven LOW to enable outputs. Leaving OE floating risks undefined output states due to internal leakage; tie OE to GND via 10 kΩ pull-down if permanently enabled, or use controlled logic for 3-state management.

What is the maximum data rate supported for clean digital switching?

Based on tPLH/tPHL ≤ 12 ns and skew ≤ 1.5 ns at 3.3V, the device reliably supports data rates up to ~40 Mbps in point-to-point routing. For bus applications, limit fan-out and maintain CL ≤ 50 pF to preserve timing margins.

Does it support hot-swap or partial power-down operation?

Yes-its power-down input protection allows inputs to safely accept 0–7 V signals even when VCC = 0 V, making it suitable for hot-swap backplane interfaces and partial-system power gating without risk of latch-up or damage.