Nexperia USA Inc. 74HC238PW,118

Overview

74HC238PW,118 from Nexperia is a 3-to-8 line decoder/demultiplexer in TSSOP16 package, featuring three binary address inputs (A0–A2), eight active-HIGH mutually exclusive outputs (Y0–Y7), and three enable inputs (E1, E2 active LOW; E3 active HIGH) for parallel expansion to 1-of-32 decoding. It operates from 2.0 V to 6.0 V, supports -40 °C to +125 °C ambient range, and is used in memory chip select decoding and address routing in industrial microcontroller systems.

For engineers reviewing the 74HC238PW,118 datasheet, 74HC238PW,118 pinout, 74HC238PW,118 application, or 74HC238PW,118 equivalent, key selection considerations include enable logic configuration (E1/E2 LOW + E3 HIGH), propagation delay at 4.5 V (17–30 ns), output drive capability (±4 mA), CMOS-level input compatibility, and TSSOP16 thermal performance with 8.5 mW/K derating above 91 °C.

Technical Context

The device implements combinational logic decoding with strict mutual exclusivity: only one output goes HIGH when all enables are satisfied and a unique 3-bit address is applied. Its triple-enable architecture (two active-LOW, one active-HIGH) enables hierarchical cascading without external inversion-four units plus one inverter yield 1-of-32 decoding.

Input clamp diodes allow safe interfacing to voltages exceeding VCC when current-limiting resistors are used. Static characteristics confirm VIH = 3.15 V (min) and VOL = 0.26 V (max) at VCC = 4.5 V/IO = 4 mA, ensuring robust noise immunity and TTL-compatible interfacing for the 74HCT variant family.

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1); 16 leads; body width 4.4 mm; 0.65 mm pitch; 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 74HCT238PW,118, the 74HC238PW,118 offers superior noise immunity at 3.3 V systems but requires level translation for pure TTL interfaces; versus SN74HC238PWR, it delivers identical electrical performance with Nexperia's optimized ESD robustness and tighter propagation delay distribution.

Availability

74HC238PW,118 is available at Aetrix Electronics and suitable for memory address decoding, microcontroller peripheral expansion, industrial I/O multiplexing, and programmable logic interface applications requiring stable component supply across extended temperature ranges.

Supply support for 74HC238PW,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 leading semiconductor manufacturer specializing in high-performance logic, analog, and discrete components, with core expertise in automotive-grade and industrial reliability standards.

The 74HC238PW,118 belongs to Nexperia's 74HC logic family-designed for low-power, high-noise-immunity digital interfacing in industrial automation, consumer electronics, and communication infrastructure equipment.

FAQ

Can the 74HC238PW,118 operate reliably at 3.3 V with 74LVC-level inputs?

Yes. At VCC = 3.3 V, VIH(min) = 2.31 V and VIL(max) = 1.32 V per datasheet Table 6, exceeding 74LVC's VOH(min) = 2.4 V and VOL(max) = 0.55 V. This provides 0.09 V noise margin for HIGH and 0.77 V for LOW, ensuring robust static compatibility without level shifters.

What is the maximum clock rate supported when using the device as a demultiplexer?

As a demultiplexer, the limiting factor is propagation delay from enable/data input to output. With E1 as data input and A0–A2 as address, tpd(E1→Yn) is 18–31 ns at VCC = 4.5 V. This supports a maximum demux switching rate of ~17 MHz (1/2 × tpd(max)) with setup/hold margin, assuming clean edge rates and 15 pF load.

Does the TSSOP16 package require thermal vias for continuous 125 °C operation?

Yes. The SOT403-1 package derates total power dissipation by 8.5 mW/K above 91 °C. At full 500 mW rating, junction temperature would exceed 125 °C without thermal relief. Use ≥4 thermal vias (0.3 mm diameter, filled) under the exposed pad area to maintain θJA ≤ 65 K/W and ensure TJ ≤ 125 °C at 100 mW typical dissipation.

How does the enable logic prevent partial output activation during power-up?

All outputs remain LOW until E1 and E2 are stable LOW *and* E3 is stable HIGH. During power ramp, VCC rise causes E3 (tied to VCC) to transition last, while E1/E2 (often pulled LOW externally) stabilize first-ensuring no output activates until full supply and enable conditions are met, preventing spurious memory writes or peripheral glitches.