Nexperia USA Inc. 74HCT238PW-Q100J

Overview

74HCT238PW-Q100 from Nexperia is an automotive-grade 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 via four ICs and one inverter, used in engine control units for peripheral address selection.

For engineers reviewing the 74HCT238PW-Q100 datasheet, 74HCT238PW-Q100 pinout, 74HCT238PW-Q100 application, or 74HCT238PW-Q100 equivalent, key selection criteria include AEC-Q100 Grade 1 qualification, TSSOP16 package compatibility, propagation delay ≤53 ns at 5 V, output drive capability of ±4 mA, and enable-input logic configuration for cascaded decoding.

Technical Context

This device implements combinational logic decoding using standard CMOS process with TTL-level input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5 V), enabling direct interface with legacy microcontroller GPIOs. Its three independent enables (E1/E2 active LOW, E3 active HIGH) provide hierarchical control for multi-layer address decoding trees.

The functional architecture supports dual-mode operation: as a 3-to-8 decoder when all enables are asserted, or as an 8-output demultiplexer by routing data to E1/E2/E3 while using remaining enables as strobes. All outputs switch actively - no open-drain or high-Z states - and feature integrated input clamp diodes for overvoltage tolerance with current-limiting resistors.

Key Specifications

Pinout & Package

TSSOP16 package (SOT403-1): plastic thin shrink small outline, 16 leads, body width 4.4 mm, 0.65 mm pitch, exposed pad optional for thermal relief.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC238PW-Q100 and SN74LV238APWR, the 74HCT238PW-Q100 uniquely balances TTL input compatibility, AEC-Q100 Grade 1 qualification, and 5 V system integration - making it the only drop-in solution for legacy automotive designs upgrading from 74LS238 without redesigning level-shifting networks.

Availability

74HCT238PW-Q100 is available at Aetrix Electronics and suitable for engine control units, body control modules, transmission control modules, and ADAS camera interface systems requiring stable component supply across extended temperature ranges and automotive lifecycle commitments.

Supply support for 74HCT238PW-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 logic, analog, and discrete components, with core expertise in automotive-qualified silicon solutions.

The 74HCT238-Q100 belongs to Nexperia's automotive logic portfolio, designed specifically for robust address decoding and signal routing in harsh-environment electronic control units where reliability, temperature resilience, and AEC-Q100 compliance are mandatory.

FAQ

What is the maximum clock frequency supported by the 74HCT238PW-Q100 when used as a demultiplexer?

The 74HCT238PW-Q100 is a combinational logic device with no internal clock - its effective switching rate depends on propagation delay and input transition times. With tpd ≤53 ns and tt ≤22 ns at 5 V, it reliably handles address/data strobe rates up to 10 MHz in demultiplexer mode, assuming clean edges and proper load capacitance (≤15 pF).

Can the 74HCT238PW-Q100 drive LEDs directly without current-limiting resistors?

No - while the outputs source/sink ±4 mA, driving even low-current LEDs (e.g., 2 mA typical) requires external series resistors to limit current and prevent VOL/VOH specification violations. For a red LED (VF ≈ 1.8 V) at 5 V, a minimum 820 Ω resistor is needed to stay within 4 mA absolute maximum rating.

How does the enable-input logic (E1, E2 LOW + E3 HIGH) simplify cascaded decoding compared to single-enable decoders?

This triple-enable scheme allows four 74HCT238PW-Q100 ICs to form a 5-to-32 decoder using only one external inverter: E3 of each chip connects to a 2-bit address bus, while E1/E2 are tied to decoded high-order bits. This eliminates 31 NAND gates required in discrete implementations and reduces propagation delay accumulation by 40%.

Is the TSSOP16 package (SOT403-1) compatible with standard reflow profiles for lead-free soldering?

Yes - the SOT403-1 package is qualified for JEDEC J-STD-020 Class 3 moisture sensitivity and supports standard Pb-free reflow profiles (peak 260 °C, 60 s above 217 °C). Its 0.65 mm pitch and coplanarity <0.1 mm ensure reliable automated optical inspection and solder joint integrity in automotive manufacturing lines.