Nexperia USA Inc. 74HCT138PW-Q100,11

Overview

74HCT138PW-Q100 from Nexperia is an automotive-grade 3-to-8 line decoder/demultiplexer with inverting outputs, TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5 V), operating from 4.5 V to 5.5 V, and qualified to AEC-Q100 Grade 1 (−40 °C to +125 °C). It features three enable inputs (E1, E2 active LOW; E3 active HIGH), eight mutually exclusive active LOW outputs (Y0–Y7), and supports memory chip select decoding in engine control units.

For engineers reviewing the 74HCT138PW-Q100 datasheet, 74HCT138PW-Q100 pinout, 74HCT138PW-Q100 application, or 74HCT138PW-Q100 equivalent, key selection criteria include TTL-level input compatibility, −40 °C to +125 °C operation, TSSOP16 package with side-wettable flanks for AOI, propagation delay ≤35 ns (VCC = 4.5 V), and automotive qualification per AEC-Q100.

Technical Context

This device implements a combinational logic decoder with three binary address inputs (A0–A2) mapped to eight active LOW outputs via fixed NAND-based decoding architecture. All outputs are HIGH unless E1 = LOW, E2 = LOW, and E3 = HIGH - enabling precise hierarchical enable control for cascaded decoding.

The multiple enable structure (two active LOW, one active HIGH) allows direct parallel expansion to 1-of-32 decoding using four ICs and one inverter, without external logic. Input clamp diodes permit safe interfacing to voltages exceeding VCC when used with current-limiting resistors.

Key Specifications

Pinout & Package

TSSOP16 plastic thin shrink small outline package (SOT403-1); 16 leads; body width 4.4 mm; side-wettable flanks for automated optical inspection (AOI) of solder joints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HC138PW-Q100, the 74HCT138PW-Q100 offers TTL input compatibility essential for mixed-logic automotive systems, while SN74LS138DR lacks AEC-Q100 qualification and thermal robustness - making the 74HCT138PW-Q100 the sole qualified option for Grade 1 under-hood deployment.

Availability

74HCT138PW-Q100 is available at Aetrix Electronics and suitable for engine control units, ADAS sensor hubs, and electric power steering systems requiring stable component supply across extended temperature ranges and automotive lifecycle commitments.

Supply support for 74HCT138PW-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 global semiconductor expert delivering high-performance, reliable components for automotive, industrial, and consumer applications, with leadership in logic, MOSFETs, and ESD protection.

The 74HCT138PW-Q100 belongs to Nexperia's automotive-qualified logic family, designed specifically for robust, low-power decoding and demultiplexing in harsh-temperature vehicle subsystems.

FAQ

What is the maximum propagation delay of the 74HCT138PW-Q100 at 5 V supply?

The maximum propagation delay (tpd) from address input (A0–A2) to any output (Y0–Y7) is 35 ns at VCC = 4.5 V and Tamb = −40 °C to +125 °C, per Table 7 of the Rev. 6 datasheet. At VCC = 5.0 V and CL = 15 pF, typical delay is 17 ns with no published maximum - design margin should use the 35 ns worst-case value.

Can the 74HCT138PW-Q100 be used as a demultiplexer, and how is it configured?

Yes - configure E1 (pin 4) as the data input (driven HIGH/LOW), E2 (pin 5) and E3 (pin 6) as strobe controls (E2 = LOW, E3 = HIGH), and A0–A2 (pins 1–3) as select lines. The selected Yx output mirrors the E1 state while all others remain HIGH, achieving 1-to-8 demultiplexing with no external components.

Does the 74HCT138PW-Q100 support 3.3 V logic interfaces?

No - the 74HCT138PW-Q100 is specified only for VCC = 4.5 V to 5.5 V and TTL-level inputs (VIH ≥ 2.0 V). Driving its inputs from 3.3 V logic violates VIH min (2.0 V) only at VCC = 5 V, but output swing (VOH ≥ 3.7 V) may not reliably drive 3.3 V CMOS inputs. Use 74LVC138 or level translators for 3.3 V systems.

Is the TSSOP16 package (SOT403-1) compatible with standard reflow profiles?

Yes - the SOT403-1 package is qualified for lead-free reflow per JEDEC J-STD-020. Peak temperature must not exceed 260 °C for ≤30 seconds, with ramp-up rate ≤3 °C/s and ramp-down rate ≤6 °C/s. Side-wettable flanks support AOI but require controlled solder paste volume to avoid bridging.