Nexperia USA Inc. 74HCT238D-Q100J

Overview

74HCT238D-Q100 from Nexperia is an automotive-qualified 3-to-8 line decoder/demultiplexer with TTL-compatible inputs, active-HIGH mutually exclusive outputs (Y0–Y7), three enable inputs (E1, E2 active LOW; E3 active HIGH), and operation across -40 °C to +125 °C. It supports memory chip select decoding and parallel expansion to 1-of-32 using four ICs and one inverter.

For engineers reviewing the 74HCT238D-Q100 datasheet, 74HCT238D-Q100 pinout, 74HCT238D-Q100 application, or 74HCT238D-Q100 equivalent, key selection criteria include automotive AEC-Q100 Grade 1 qualification, SO16 package compatibility, propagation delay ≤53 ns at VCC = 5.0 V, TTL-level input thresholds, and demultiplexing capability with three independent enables.

Technical Context

This device implements combinational logic decoding of three binary address inputs (A0–A2) into eight active-HIGH outputs, where output activation requires E1 = LOW, E2 = LOW, and E3 = HIGH. The enable architecture enables cascading without external logic inversion.

It features input clamp diodes for overvoltage tolerance, JEDEC-standard compliance (JESD7A), and dual supply voltage support: 4.5–5.5 V for 74HCT operation with TTL-level input recognition (VIH = 2.0 V min, VIL = 0.8 V max).

Key Specifications

Pinout & Package

74HCT238D-Q100 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. Pin 1 index is marked by a notch or bevel on the package top edge.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC238D-Q100, the 74HCT238D-Q100 offers tighter input threshold alignment with legacy TTL sources but sacrifices supply voltage flexibility; versus SN74LS238N, it delivers AEC-Q100 qualification and lower static current, enabling direct drop-in replacement in automotive production without requalification.

Availability

74HCT238D-Q100 is available at Aetrix Electronics and suitable for engine control units, ADAS sensor hubs, instrument cluster displays, and body control modules requiring stable component supply across automotive production lifecycles.

Supply support for 74HCT238D-Q100 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 leading semiconductor manufacturer specializing in high-performance, high-reliability logic, analog, and discrete components for automotive, industrial, and consumer markets.

The 74HCT238-Q100 series belongs to Nexperia's automotive-qualified logic portfolio, designed specifically for robust address decoding and signal routing in safety-critical vehicle subsystems operating across extended temperature ranges.

FAQ

Is 74HCT238D-Q100 pin-compatible with standard 74HCT238 packages?

Yes - the D suffix denotes the SO16 (SOT109-1) package, which matches industry-standard pinout for 74HCT238 devices. Pin assignments for A0–A2, E1–E3, Y0–Y7, VCC, and GND are identical across manufacturers' SO16 variants, enabling direct substitution in existing layouts.

What is the maximum clock frequency supported for demultiplexing operation?

The device does not operate on a clock; it is purely combinational. Maximum data rate is governed by propagation delay: at VCC = 5.0 V and CL = 15 pF, tpd ≤ 21 ns (74HCT238), supporting input signal transitions up to ~24 MHz for reliable setup/hold margins in synchronous demux configurations.

Can E1, E2, or E3 be left unconnected in circuit design?

No - all enable inputs must be actively driven. Floating E1 or E2 (active LOW) may cause unintended output activation due to noise coupling; floating E3 (active HIGH) may prevent decoding entirely. Tie unused enables to appropriate logic levels via pull-up/pull-down resistors per functional intent.

Does 74HCT238D-Q100 support hot insertion or live insertion into powered systems?

No - the device lacks hot-swap protection circuitry. Applying VCC before establishing proper GND connection or asserting enables during power ramp may cause latch-up or excessive current draw. Power sequencing per manufacturer guidelines (GND first, then VCC, then inputs) is mandatory for reliability.