Nexperia USA Inc. 74AHC138BQ-Q100X

Overview

74AHC138BQ-Q100 from Nexperia is an automotive-qualified 3-to-8 line inverting decoder/demultiplexer in DHVQFN16 package, operating from 2.0 V to 5.5 V with propagation delays as low as 4.2 ns (VCC = 4.5–5.5 V, CL = 15 pF), featuring three enable inputs (E1, E2 active LOW; E3 active HIGH) and eight mutually exclusive active-LOW outputs (Y0–Y7). It enables memory chip select decoding and parallel expansion to 1-of-32 decoding in automotive control modules.

For engineers reviewing the 74AHC138BQ-Q100 datasheet, 74AHC138BQ-Q100 pinout, 74AHC138BQ-Q100 application, or 74AHC138BQ-Q100 equivalent, key selection considerations include its AEC-Q100 Grade 1 qualification (-40 °C to +125 °C), CMOS-level input compatibility, balanced propagation delays, Schmitt-trigger inputs, and DHVQFN16 package with side-wettable flanks for AOI-capable solder joint inspection.

Technical Context

The device implements a combinational logic decoder with three binary address inputs (A0–A2) and three enable inputs governing output activation: all eight outputs remain HIGH unless E1 = LOW, E2 = LOW, and E3 = HIGH. Its inverting architecture ensures selected outputs drive LOW while unselected outputs remain HIGH, supporting both decoding and demultiplexing modes.

It supports dual-mode operation: as a decoder when all enables are used for hierarchical selection, or as an 8-output demultiplexer by routing data through one active-LOW enable (e.g., E1) while using the others as strobes. Input clamping diodes, Schmitt-trigger action on all inputs, and TTL/CMOS-level compatibility (AHC variant) ensure robust noise immunity and interoperability across mixed-voltage systems.

Key Specifications

Pinout & Package

DHVQFN16 (SOT763-1) package: 2.5 mm × 3.5 mm × 0.85 mm body, no leads, side-wettable flanks for automated optical inspection of solder joints; thermal-enhanced construction improves power handling in dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74AHCT138BQ-Q100, the 74AHC138BQ-Q100 offers superior noise immunity via higher VIH/VIL thresholds, while SN74LV138APWR trades automotive qualification for broader low-voltage operation - making the AHC variant optimal for new AEC-Q100-compliant designs demanding robustness in 3.3 V/5 V hybrid systems.

Availability

74AHC138BQ-Q100 is available at Aetrix Electronics and suitable for automotive body control modules, engine management systems, ADAS domain controllers, and electric power steering ECUs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74AHC138BQ-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.

This device belongs to Nexperia's AEC-Q100-qualified automotive logic family, designed specifically for high-reliability decoding, demultiplexing, and signal routing in harsh-temperature electronic control units.

FAQ

What is the maximum clock frequency supported by the 74AHC138BQ-Q100?

The 74AHC138BQ-Q100 is a combinational logic device without an internal clock; its effective operating frequency depends on propagation delay and load capacitance. With tpd ≤ 10.5 ns (VCC = 4.5–5.5 V, CL = 15 pF), it supports address/data switching rates up to approximately 95 MHz in ideal conditions - though system-level timing margins and board parasitics typically limit practical use to ≤ 50 MHz.

Can the 74AHC138BQ-Q100 be used as a demultiplexer, and how is it configured?

Yes - configure E1 (pin 5) as the data input (driven LOW/HIGH), A0–A2 (pins 13–14, 8) as address lines, and tie E2 (pin 11) LOW and E3 (pin 4) HIGH to enable. Each combination of A0–A2 routes the E1 signal to exactly one of Y0–Y7, with all other outputs held HIGH. Unused enables must be hard-wired to valid logic states.

Does the thermal pad (pin 1) require connection to ground?

No - pin 1 is a non-electrical thermal pad. Per Nexperia's datasheet, it has no electrical function and may be left floating or connected to GND; if soldered, the land must remain electrically isolated or tied to GND. Its purpose is mechanical stability and thermal conduction, not circuit reference.

How does the 74AHC138BQ-Q100 differ from the standard 74AHC138 (non-Q100)?

The -Q100 suffix denotes full AEC-Q100 Grade 1 qualification: extended temperature operation (-40 °C to +125 °C), rigorous stress testing (HTOL, TC, UHAST), and certified manufacturing traceability. Electrically identical, it adds automotive-specific reliability validation, lot-level documentation, and controlled change notification - mandatory for Tier 1 automotive suppliers.