Nexperia USA Inc. 74HCT238PW,112

Overview

74HCT238PW,112 from Nexperia is a 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 4.5 V to 5.5 V supply. It decodes binary address inputs A0–A2 for memory chip select decoding in industrial microcontroller systems and supports parallel expansion to 1-of-32 decoding using four ICs and one inverter.

For engineers reviewing the 74HCT238PW,112 datasheet, 74HCT238PW,112 pinout, 74HCT238PW,112 application, or 74HCT238PW,112 equivalent, key selection factors include TTL-level input compatibility, propagation delay ≤53 ns at 5 V, TSSOP16 package thermal performance, and demultiplexing capability using E1/E2 as strobes and E3 as data input.

Technical Context

The 74HCT238PW,112 implements combinational logic decoding with strict truth-table-defined output activation: only one of Y0–Y7 goes LOW when E1=E2=L, E3=H, and a unique A0–A2 combination is present. Its enable architecture enables hierarchical decoding without external logic.

Input clamping diodes allow interfacing to voltages exceeding VCC when used with current-limiting resistors. The device complies with JEDEC JESD7A (2.0–6.0 V) and JESD8C (2.7–3.6 V), and meets JESD78 Class II Level B latch-up immunity (>100 mA).

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1); 16 leads; body width 4.4 mm; 0.65 mm lead 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,112, the 74HC238PW,118 offers broader supply flexibility but lacks TTL input compatibility, while SN74LS238N matches input thresholds but imposes thermal and lifecycle constraints unsuitable for modern industrial deployments.

Availability

74HCT238PW,112 is available at Aetrix Electronics and suitable for memory decoding, peripheral expansion, bus interface, and industrial control applications requiring stable component supply across extended temperature ranges.

Supply support for 74HCT238PW,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 leading semiconductor manufacturer specializing in high-performance logic, analog, and discrete components, with global R&D and manufacturing facilities focused on reliability and energy efficiency.

The 74HCT238PW,112 belongs to Nexperia's 74HCT logic family, designed specifically for seamless integration between TTL and CMOS systems in industrial, automotive (non-safety), and computing applications.

FAQ

What is the maximum clock frequency supported by the 74HCT238PW,112?

The 74HCT238PW,112 is a static combinational logic device with no internal clock; its effective operating frequency depends on input transition rates and propagation delay. With tPD ≤53 ns at VCC = 5 V, it supports address/data update rates up to approximately 10 MHz in worst-case timing paths, assuming clean edges and minimal load capacitance.

Can the 74HCT238PW,112 be used as a demultiplexer, and how is it configured?

Yes - configure E3 as the data input (driven HIGH/LOW), A0–A2 as select lines, and E1/E2 as strobes (held LOW). When E1=E2=L, the state of E3 appears inverted on the selected Y output (e.g., E3=H → Yx=L). This provides true 1-to-8 demux functionality with guaranteed mutual exclusivity.

Does the 74HCT238PW,112 require external pull-up or pull-down resistors on its inputs or outputs?

No - inputs have internal clamp diodes and defined VIH/VIL thresholds; outputs are push-pull and actively drive HIGH or LOW. Pull-ups are unnecessary unless open-collector emulation is needed (not supported). Unused inputs should be tied to VCC or GND to prevent floating states and reduce noise susceptibility.

How does the TSSOP16 package (SOT403-1) of the 74HCT238PW,112 compare thermally to SO16?

The TSSOP16 package has a thermal resistance θJA of ~118 K/W (vs ~100 K/W for SO16), meaning it runs warmer at equal power dissipation. However, its smaller footprint and thinner profile improve PCB heat spreading when mounted on copper planes. Derating begins above +91 °C ambient, with linear Ptot reduction of 8.5 mW/K.