Nexperia USA Inc. 74AHC138PW,112

Overview

74AHC138PW,112 from Nexperia is a high-speed CMOS 3-to-8 line inverting decoder/demultiplexer with three binary address inputs (A0–A2), eight active-low mutually exclusive outputs (Y0–Y7), and three enable inputs (E1, E2 active LOW; E3 active HIGH). It operates from 2.0 V to 5.5 V, delivers propagation delays as low as 4.2 ns (VCC = 5 V, CL = 15 pF), and supports industrial temperature range (−40 °C to +125 °C) in TSSOP16 package. It is widely used for memory chip select decoding and hierarchical address expansion in embedded control systems.

For engineers reviewing the 74AHC138PW,112 datasheet, 74AHC138PW,112 pinout, 74AHC138PW,112 application, or 74AHC138PW,112 equivalent, key selection considerations include its CMOS-level input compatibility (VIH ≥ 3.85 V at VCC = 5.5 V), guaranteed 8 mA output drive strength, balanced tPLH/tPHL timing, Schmitt-trigger input action for noise immunity, and multi-enable architecture enabling 1-of-32 decoding with four devices and one inverter.

Technical Context

The 74AHC138PW,112 implements a fully static, non-latched 3-to-8 decoding function with active-low outputs and three independent enable controls-two active-low (E1, E2) and one active-high (E3)-requiring all three to be asserted simultaneously (E1=L, E2=L, E3=H) for any output to go LOW. Its logic is strictly combinational with no internal state retention.

All inputs feature Schmitt-trigger action for hysteresis-based noise rejection, and the device accepts input voltages up to 7.0 V regardless of VCC, supporting mixed-voltage interfacing. Propagation delays are tightly balanced between address-to-output (An→Yn) and enable-to-output (E1/E2/E3→Yn) paths, with typical tpd of 4.4 ns (5 V, 15 pF) and maximum 10.5 ns across −40 °C to +125 °C.

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1), 16-pin, body width 4.4 mm, lead pitch 0.65 mm, exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74AHCT138PW,112, the 74AHC138PW,112 offers superior noise immunity and lower dynamic power in pure CMOS systems, while SN74HC138PWR trades speed and thermal performance for broader voltage flexibility and lower procurement cost in non-industrial settings.

Availability

74AHC138PW,112 is available at Aetrix Electronics and suitable for memory address decoding, peripheral multiplexing, bus expansion interfaces, and logic-level translation hubs requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for 74AHC138PW,112 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 headquartered in Nijmegen, Netherlands, specializing in high-performance analog, logic, and discrete components for automotive, industrial, and consumer markets.

The 74AHC138PW,112 belongs to Nexperia's AHC logic family, engineered for high-speed, low-power, and wide-voltage-operation applications in resource-constrained embedded systems and industrial control units.

FAQ

What is the maximum clock/data frequency supported by the 74AHC138PW,112?

The 74AHC138PW,112 is a combinational logic device with no internal clock; its usable frequency depends on input transition rate and load capacitance. With CL = 15 pF and VCC = 5 V, it supports input edge rates up to 20 ns/V (i.e., ~50 MHz square wave), but practical use is limited by propagation delay (≤10.5 ns worst-case) and system timing margins-not by a defined clock frequency.

Can unused enable inputs be left floating?

No. Unused enable inputs must be permanently tied to their defined active state: E1 and E2 to GND (LOW), E3 to VCC (HIGH). Floating enables risk metastability, increased ICC, or unintended output activation due to noise coupling, violating the functional table's "X = don't care" condition only when other enables enforce disable.

Does the 74AHC138PW,112 support hot-swap or live-insertion?

No. The device lacks hot-swap protection circuitry. Applying VCC before GND, or asserting inputs before supply stabilization, may exceed absolute maximum ratings (e.g., VI > VCC + 0.5 V), risking latch-up or permanent damage. Power sequencing per JEDEC JESD8-12 (VCC before inputs) is mandatory.

How does the Schmitt-trigger action improve system reliability?

Schmitt-trigger inputs provide hysteresis (≥0.5 V typical) that prevents multiple output transitions during slow-rising/falling or noisy input edges. This eliminates contact bounce artifacts in manual switch interfaces and suppresses EMI-induced glitches on long PCB traces-critical in factory automation and motor-control feedback paths.