STMicroelectronics 74LCX32TTR

Overview

74LCX32TTR from STMicroelectronics is a low-voltage CMOS quad 2-input OR gate with 5V-tolerant inputs, operating at 2.0–3.6 V supply. It delivers symmetrical 24 mA output drive (|IOH| = IOL), 5.2 ns max propagation delay at VCC = 3 V, and latch-up immunity >500 mA - deployed in 3.3 V PCI bus interface logic where 5 V signal compatibility and rail-to-rail noise margin are required.

For engineers reviewing the 74LCX32TTR datasheet, 74LCX32TTR pinout, 74LCX32TTR application, or 74LCX32TTR equivalent, key selection criteria include 5 V input tolerance, balanced tPLH/tPHL propagation delays, ±24 mA drive capability at 3 V, and TSSOP-14 package thermal performance for high-density board layouts.

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 power-down protection ensures safe high-impedance behavior on inputs/outputs when VCC = 0 V.

Dynamic specifications guarantee matched tPLH ≅ tPHL propagation delays and <1.0 ns output-to-output skew under 50 pF load, supporting synchronous multi-gate timing integrity in address decoding and bus arbitration circuits.

Key Specifications

Pinout & Package

TSSOP-14 package: 4.4 mm × 5.0 mm body, 0.65 mm pitch, 1.2 mm height, JEDEC MO-153 compliant; optimized for automated SMT assembly and thermal dissipation in compact PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC32APWR and 74ALVC32PW, the 74LCX32TTR uniquely combines 5 V input tolerance, power-down protection, and >500 mA latch-up immunity - making it the sole choice for hot-pluggable or mixed-voltage industrial interfaces where reliability under fault conditions is mandatory.

Availability

74LCX32TTR is available at Aetrix Electronics and suitable for PCI bus interface design, low-power embedded control, and industrial I/O expansion requiring stable component supply across extended temperature ranges (–55 °C to +125 °C).

Supply support for 74LCX32TTR 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 - developed specifically for PCI, embedded computing, and industrial control applications where power efficiency and robustness coexist.

FAQ

Can 74LCX32TTR operate with VCC = 2.0 V while maintaining guaranteed VIH/VIL thresholds?

Yes. The datasheet guarantees VIH ≥ 2.0 V and VIL ≤ 0.8 V across the full recommended VCC range of 2.0–3.6 V at temperatures from –55 °C to +125 °C. At VCC = 2.0 V, VIH remains 2.0 V, ensuring compatibility with 1.8 V logic outputs driving its inputs via pull-up or direct connection.

Does 74LCX32TTR require external pull-up resistors on inputs or outputs?

No. Inputs have no internal pull-ups; external resistors are needed only if floating-state prevention is required by system logic. Outputs are push-pull and do not require pull-ups. However, a 100 nF ceramic capacitor must be placed between VCC and GND near pin 14 for stable operation.

What is the maximum capacitive load the 74LCX32TTR can drive while maintaining 5.2 ns tPD?

The 5.2 ns max tPD is specified at CL = 50 pF, including probe and jig capacitance. Driving loads >50 pF increases propagation delay nonlinearly; for 75 pF, tPD rises to ~6.9 ns. For heavier loads, consider buffering or reducing trace length to maintain timing margins.

Is 74LCX32TTR pin-compatible with standard 74LS32 or 74HC32 in TSSOP-14?

Yes - it is functionally and pinout-compatible with 74-series quad 2-input OR gates (e.g., 74LS32, 74HC32) in TSSOP-14. Pin numbering, logic function, and terminal assignment match exactly, enabling drop-in replacement where 3.3 V operation and 5 V input tolerance are needed.