Nexperia USA Inc. 74AHC138D-Q100J

Overview

74AHC138D-Q100 from Nexperia is an automotive-grade 3-to-8 line inverting decoder/demultiplexer in SO16 package, operating from 2.0 V to 5.5 V with propagation delay as low as 4.4 ns (VCC = 5.0 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 is AEC-Q100 Grade 1 qualified (−40 °C to +125 °C) and used for memory chip select decoding in engine control units and ADAS domain controllers.

For engineers reviewing the 74AHC138D-Q100 datasheet, 74AHC138D-Q100 pinout, 74AHC138D-Q100 application, or 74AHC138D-Q100 equivalent, key selection criteria include its CMOS-level input compatibility, balanced propagation delays across all paths (An→Yn, E3→Yn, E1/E2→Yn), Schmitt-trigger input action, and support for parallel expansion to 1-of-32 decoding using four devices and one inverter.

Technical Context

The device implements a fully static CMOS 3-to-8 decoder with three binary address inputs (A0–A2), three enable inputs (two active-LOW, one active-HIGH), and eight active-LOW outputs. All inputs exhibit Schmitt-trigger action for noise immunity, and outputs drive up to ±25 mA with VOH ≥ 3.94 V (IO = −8 mA, VCC = 4.5 V) and VOL ≤ 0.36 V (IO = 8 mA).

It supports demultiplexing by routing data through an enable input while using others as strobes, and enables hierarchical decoding via cascaded enable logic-E1 and E2 must both be LOW and E3 HIGH for any output to go LOW. The function table confirms strict mutual exclusivity: only one Yn is LOW per valid address/enable combination.

Key Specifications

Pinout & Package

74AHC138D-Q100 uses the SO16 plastic small outline package (SOT109-1), 16-pin, 3.9 mm body width, with gull-wing leads and standard JEDEC MS-012 footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74AHCT138D-Q100 and SN74LV138AQPWRQ1, the 74AHC138D-Q100 delivers the fastest propagation delay at 5 V operation and highest noise margin for pure CMOS systems, making it optimal for high-speed automotive microcontroller address decoding where timing margin is constrained.

Availability

74AHC138D-Q100 is available at Aetrix Electronics and suitable for engine control units, ADAS domain controllers, and automotive infotainment systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 74AHC138D-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 leading semiconductor manufacturer specializing in high-performance logic, analog, and MOSFET solutions, with core expertise in automotive-qualified components and energy-efficient logic families.

The 74AHC138D-Q100 belongs to Nexperia's AHC-Q100 automotive logic portfolio, engineered specifically for robust, low-power address decoding and signal routing in safety-critical vehicle subsystems.

FAQ

Can 74AHC138D-Q100 operate at 3.3 V supply while interfacing with 5 V inputs?

Yes. Its inputs accept voltages up to 5.5 V regardless of VCC (2.0 V to 5.5 V), enabling safe 5 V-tolerant operation at 3.3 V supply. This allows direct connection to legacy 5 V microcontrollers or sensors without level shifters, while maintaining full CMOS noise margins and guaranteed logic thresholds per datasheet Table 6.

What is the maximum fan-out capability of each Yn output?

Each Yn output can drive up to 10 LSTTL loads (IO = ±25 mA, VOL ≤ 0.36 V at 8 mA sink) or 20 CMOS loads (II ≤ 1 μA). At VCC = 5.0 V and 25 °C, the output maintains VOH ≥ 3.94 V and VOL ≤ 0.36 V across full rated current, supporting direct connection to memory /CE pins and peripheral enable inputs without buffering.

How does the multiple-enable architecture support 1-of-32 decoding?

By connecting E1 and E2 of four 74AHC138D-Q100 devices to decoded upper address bits (A3, A4), and tying E3 HIGH on all, only one device is enabled per 8-output block. An external inverter generates the complement needed for full 5-bit decode. This achieves 1-of-32 selection using only four ICs and one passive component-no additional logic gates required.

Is the DHVQFN package option (74AHC138BQ-Q100) pin-compatible with 74AHC138D-Q100?

No. While functionally identical, the DHVQFN16 (SOT763-1) has different pin mapping: GND appears on terminals 1 and 8, Y7–Y5 occupy pins 2–4, and A0–A2 are on pins 15–13. The SO16 (SOT109-1) places GND at pin 8 and Y0–Y7 at pins 7,9–15. PCB layout and footprint are not interchangeable-designers must use package-specific land patterns.