Nexperia USA Inc. 74LVC138AD,118

Overview

74LVC138AD,118 from Nexperia is a 3-to-8 line inverting decoder/demultiplexer with three active-Low enable inputs (E1, E2) and one active-High enable input (E3), operating across 1.2 V to 3.6 V supply, delivering mutually exclusive outputs (Y0–Y7), and supporting mixed-voltage interfacing (3.3 V/5 V) in memory chip select and address decoding applications.

For engineers reviewing the 74LVC138AD,118 datasheet, 74LVC138AD,118 pinout, 74LVC138AD,118 application, or 74LVC138AD,118 equivalent, key selection criteria include its wide VCC range (1.2–3.6 V), Schmitt-trigger inputs for noise immunity, -40 °C to +125 °C industrial temperature rating, and SO16 package compatibility with legacy PCB footprints.

Technical Context

The 74LVC138AD implements a combinational logic decoder with three binary address inputs (A0–A2) selecting exactly one of eight inverted outputs (Y0–Y7) when E1=E2=L and E3=H. Its multiple enable architecture enables cascading into larger decoders (e.g., 1-of-32) using only four ICs and one external inverter.

All inputs feature Schmitt-trigger action, tolerating slow rise/fall times, and overvoltage tolerance up to 5.5 V allows direct interfacing with both 3.3 V and 5 V logic families without level shifters-critical for mixed-supply system integration.

Key Specifications

Pinout & Package

74LVC138AD,118 is housed in a plastic small outline package (SO16, SOT109-1) with 16 leads, 3.9 mm body width, and standard 1.27 mm lead pitch - compatible with automated pick-and-place and reflow soldering per IPC-J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 3-to-8 decoder applications.

Compared with SN74LV138APWR and 74AHC138PW,118, the 74LVC138AD,118 uniquely balances ultra-wide voltage scalability (1.2–3.6 V), industrial temperature range, and overvoltage tolerance-making it the optimal choice for next-generation energy-efficient embedded controllers requiring backward compatibility with legacy 5 V peripherals.

Availability

74LVC138AD,118 is available at Aetrix Electronics and suitable for memory address decoding, industrial I/O expansion, embedded boot configuration, and FPGA peripheral selection requiring stable component supply across extended temperature and mixed-voltage environments.

Supply support for 74LVC138AD,118 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

Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74LVC138A belongs to Nexperia's LVC (Low-Voltage CMOS) logic family, engineered for low-power, high-noise-immunity digital interfacing in space-constrained and thermally demanding applications.

FAQ

What is the minimum supply voltage for reliable operation of the 74LVC138AD,118?

The 74LVC138AD,118 is fully specified down to 1.2 V VCC, with guaranteed functionality including propagation delay, output drive, and input thresholds across the full -40 °C to +125 °C temperature range. Below 1.2 V, performance is not characterized and may result in metastability or incomplete logic transitions.

Can the 74LVC138AD,118 be used as a demultiplexer, and how is it configured?

Yes: configure E3 as the data input (active-HIGH), and use E1 and E2 as strobe controls. With A0–A2 selecting the output line, the selected Yx output mirrors the E3 state (inverted), while all others remain HIGH. This provides true 1-to-8 demux behavior without additional components.

Does the SO16 package (SOT109-1) of the 74LVC138AD,118 require thermal pad grounding?

No - the SO16 package has no exposed thermal pad. Pin 8 is the sole GND connection. The datasheet explicitly states that any metalized area labeled "GND" in pin diagrams (e.g., Fig. 6 for DHVQFN) does not apply to SOT109-1; thermal management relies solely on PCB copper pour connected to pin 8.

How does the Schmitt-trigger input improve system reliability in industrial settings?

Schmitt-trigger inputs provide hysteresis (typically 0.3–0.5 V), preventing multiple output transitions caused by slow-rising or noisy signals - common in long cable runs, relay feedback loops, or proximity sensor interfaces. This eliminates need for external RC filtering and ensures clean, glitch-free decoding in harsh electromagnetic environments.