STMicroelectronics 74LCX32MTR

Overview

74LCX32MTR from STMicroelectronics is a low-voltage CMOS quad 2-input OR gate with 5V-tolerant inputs, operating at 2.0–3.6 V supply, delivering 5.2 ns max propagation delay at 3.0 V, ±24 mA output drive, and symmetrical output impedance-used in 3.3 V logic interfacing with legacy 5 V buses in telecom line cards and industrial I/O modules.

For engineers reviewing the 74LCX32MTR datasheet, 74LCX32MTR pinout, 74LCX32MTR application, or 74LCX32MTR equivalent, key selection criteria include 5V input tolerance, PCI bus-level drive capability at 24 mA, balanced tPLH/tPHL delays, and power-down protection for hot-swap I/O staging.

Technical Context

This device implements four independent OR logic functions using sub-micron C2MOS technology, enabling full 3.3 V operation while accepting 0–5.5 V input signals without level shifters. Its input diode clamping and power-down protection ensure safe operation during partial power-up or system suspend states.

The symmetrical output drive (|IOH| = IOL ≥ 24 mA at VCC = 3.0 V) and matched propagation delays (tPLH ≅ tPHL) support clean signal integrity in bidirectional data paths and synchronous bus arbitration circuits where skew-sensitive timing is required.

Key Specifications

Pinout & Package

74LCX32MTR is housed in a 14-lead SOIC (Small Outline Integrated Circuit) package with standard 1.27 mm pitch, compliant with JEDEC MS-012 and PO13G mechanical specifications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad 2-input OR gate applications.

Compared with 74LCX32MTR, the 74LVC32APW offers lower static power but no output 5V tolerance, while SN74AHC32DR supports full 5 V operation but cannot accept 5 V inputs at 3.3 V supply-making 74LCX32MTR uniquely suited for 3.3 V core + 5 V peripheral interfacing without added components.

Availability

74LCX32MTR is available at Aetrix Electronics and suitable for telecom infrastructure control, industrial PLC I/O expansion, and PCI-compliant peripheral interface design requiring stable component supply across extended temperature ranges (–55 °C to +125 °C).

Supply support for 74LCX32MTR 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 analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

The 74LCX logic family targets high-speed, low-voltage 3.3 V systems requiring 5 V signal compatibility-optimized for PCI, embedded control, and mixed-supply board-level integration.

FAQ

Is 74LCX32MTR pin-compatible with standard 74LS32 or 74HC32?

Yes, it is pin- and function-compatible with the 74-series 32 OR gate footprint (SO-14), including identical pin numbering and truth table behavior. However, its 5V-tolerant inputs and 3.3 V supply operation differ electrically from 74LS32 (5 V only) and 74HC32 (non-5V-tolerant), requiring appropriate voltage domain planning.

Can 74LCX32MTR safely drive a 50 Ω transmission line?

No-it is not designed for direct 50 Ω line driving. Its 24 mA output drive corresponds to ~125 Ω typical output impedance at 3.3 V, making it suitable for CMOS loads and bus stubs, but not for unterminated 50 Ω lines. Use a dedicated line driver (e.g., SN65LVDS1) for such applications.

What is the maximum input frequency supported for reliable OR operation?

While not explicitly rated for clocked operation, its 5.2 ns max propagation delay supports reliable combinational logic operation up to ~100 MHz toggle rate under load (CL = 50 pF). For synchronous clock distribution, a dedicated clock buffer is recommended instead.

Does 74LCX32MTR support partial power-down (e.g., VCC = 0 V while inputs active)?

Yes-its power-down protection circuitry limits Ioff to ≤10 µA when VCC = 0 V and inputs are at 5.5 V, preventing back-current flow and ensuring safe operation during hot-swap or staged power sequencing scenarios.