Nexperia USA Inc. 74HC138BQ-Q100,115

Overview

74HC138BQ-Q100 from Nexperia is an automotive-grade 3-to-8 line inverting decoder/demultiplexer with three active-LOW enable inputs (E1, E2), one active-HIGH enable input (E3), and eight mutually exclusive active-LOW outputs (Y0–Y7). It operates across 2.0–6.0 V supply, supports -40 °C to +125 °C ambient, and features CMOS-level inputs for low power and high noise immunity. It is used in automotive memory chip select decoding and address demultiplexing.

For engineers reviewing the 74HC138BQ-Q100 datasheet, 74HC138BQ-Q100 pinout, 74HC138BQ-Q100 application, or 74HC138BQ-Q100 equivalent, key selection criteria include its AEC-Q100 Grade 1 qualification, DHVQFN16 package with side-wettable flanks, propagation delay down to 12 ns at VCC = 6.0 V, and compatibility with both HC and HCT logic families via dual part numbering.

Technical Context

The device implements a standard 3-input binary decoder with inverted output logic: only one of Y0–Y7 goes LOW when all enables are satisfied (E1 = LOW, E2 = LOW, E3 = HIGH) and a unique A2:A0 combination is present. Its multiple enable architecture enables cascading-e.g., four units plus one inverter achieve 1-of-32 decoding without external logic.

Input clamping diodes allow safe interfacing to voltages exceeding VCC when used with current-limiting resistors. All inputs tolerate overvoltage conditions per JESD7A, and outputs drive ±25 mA with guaranteed VOL ≤ 0.4 V at IO = 5.2 mA and VCC = 6.0 V.

Key Specifications

Pinout & Package

DHVQFN16 package (SOT763-1): 2.5 × 3.5 × 0.85 mm body, no leads, 16 terminals, side-wettable flanks for AOI-compatible solder joint inspection. Exposed thermal pad (terminal 1) is electrically isolated unless connected to GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74HCT138BQ-Q100, the HC version offers lower static current and wider voltage flexibility but requires CMOS-compatible drivers; SN74LS138DR lacks automotive qualification, thermal performance, and supply range - making it unsuitable for new automotive designs.

Availability

74HC138BQ-Q100 is available at Aetrix Electronics and suitable for automotive body control modules, infotainment memory expansion, and ADAS sensor interface applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74HC138BQ-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 logic, analog, and MOSFET solutions optimized for automotive, industrial, and consumer applications.

The 74HC138-Q100 belongs to Nexperia's automotive-qualified logic family, designed specifically for reliable signal routing, address decoding, and chip select generation in harsh-temperature vehicle subsystems.

FAQ

What is the maximum clock/data rate supported by the 74HC138BQ-Q100?

The 74HC138BQ-Q100 is not a clocked device and has no clock input; it is combinational logic. Its maximum usable switching rate is determined by propagation delay and transition time: tpd ≤ 38 ns and tt ≤ 19 ns at VCC = 6.0 V, enabling reliable operation with address changes up to ~12 MHz in worst-case timing paths. System-level timing must account for setup/hold margins relative to enable assertion.

Can the 74HC138BQ-Q100 be used as a demultiplexer, and how?

Yes - configure one active-LOW enable input (e.g., E1) as the data input, hold the other two enables (E2 = LOW, E3 = HIGH) constant, and apply A2:A0 as the 3-bit channel select. The selected Yn output mirrors the inverted E1 signal. This provides 1-to-8 demux functionality with guaranteed mutual exclusivity and no additional components required.

Is the thermal pad (pin 1) required to be soldered or grounded?

No - terminal 1 is a non-electrical thermal pad with no electrical requirement. It may be left unsoldered, floated, or connected to GND for enhanced thermal performance. If soldered, the land must remain electrically isolated unless explicitly tied to GND; it is not internally connected to any circuit node.

How does the 74HC138BQ-Q100 differ from the 74HC138D-Q100?

The 74HC138BQ-Q100 uses a DHVQFN16 package (SOT763-1) with side-wettable flanks for AOI, measuring 2.5 × 3.5 × 0.85 mm. The 74HC138D-Q100 uses SO16 (SOT109-1), 10.0 × 3.9 × 1.75 mm. Both share identical logic, timing, and AEC-Q100 qualification, but BQ enables higher-density automotive PCB layouts and automated solder-joint inspection.