Diodes Incorporated ACX124EUQ-7R

Overview

ACX124EUQ from Diodes Incorporated is a small-signal complementary pre-biased dual transistor in SOT363 package, integrating one NPN and one PNP transistor with built-in 22 kΩ bias resistors per emitter. It delivers ±100 mA max collector current, ±30 mA output current, and 250 MHz f_T, designed for automotive-level signal switching in space-constrained PCBs.

For engineers reviewing the ACX124EUQ datasheet, ACX124EUQ pinout, ACX124EUQ application, or ACX124EUQ equivalent, this device supports AEC-Q101-compliant digital logic interfacing, level translation, and discrete gate driving where dual-polarity active switching with integrated biasing is required.

Technical Context

The ACX124EUQ implements two independent pre-biased transistors - one NPN (pins 1–2–3) and one PNP (pins 3–4–5) - sharing emitter terminal (pin 3). Each section includes matched 22 kΩ base-emitter and base-collector resistors enabling direct TTL/CMOS-compatible drive without external bias networks.

It operates across –55°C to +150°C, supports ±50 V V_CC, and maintains guaranteed VI(on)/VI(off) thresholds (±3.0 V / ±0.5 V) and VO(on) ≤ ±0.3 V at IO = ±5 mA, ensuring robust noise immunity and low saturation voltage in automotive control modules.

Key Specifications

Pinout & Package

Package: SOT363 - 6-pin, surface-mount plastic package with 0.65 mm pitch, UL 94V-0 rated molding compound, matte tin-plated leads, and moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar complementary pre-biased transistor applications.

Compared with NSBC114EDXV6T1G and EMX124RMT2G, the ACX124EUQ uniquely balances automotive qualification, compact SOT363 size, and precise 22 kΩ bias matching - making it optimal for space-constrained AEC-Q101 designs needing exact VI(on)/VI(off) thresholds and thermal stability up to +150°C.

Availability

ACX124EUQ is available at Aetrix Electronics and suitable for automotive body control modules, industrial PLC input conditioning, and USB-C power path management requiring stable component supply, long-term lifecycle assurance, and AEC-Q101 compliance.

Supply support for ACX124EUQ 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability components for automotive, industrial, and computing markets.

The ACX124EUQ belongs to Diodes' Automotive-Grade Pre-Biased Transistor (PBT) product line, engineered specifically for replacing discrete transistor-resistor combinations in AEC-Q101-compliant control nodes where board space, thermal performance, and qualification rigor are critical.

FAQ

What is the maximum junction temperature and thermal resistance of the ACX124EUQ?

The ACX124EUQ has an operating junction temperature range of –55°C to +150°C and a thermal resistance R_θJA of 450°C/W when mounted on a minimum-copper FR4 PCB. Its 270 mW total power dissipation is derated linearly above +25°C ambient, reaching zero at +85°C ambient under standard layout conditions.

Can the ACX124EUQ replace two separate pre-biased transistors in a design?

Yes - the ACX124EUQ integrates one NPN and one PNP transistor with matched 22 kΩ bias resistors in a single SOT363 package. It replaces two discrete pre-biased devices (e.g., ACX114EUQ + ACX124EUQ), reducing PCB area by ~50%, eliminating four external resistors, and ensuring matched thermal behavior between channels.

Does the shared emitter (pin 3) require special layout considerations?

Yes - pin 3 serves as the common emitter for both transistors and must be connected to a low-impedance reference (e.g., ground or bias rail) with minimal trace inductance. Avoid routing high-frequency signals near this node, and use dedicated via(s) to internal ground plane to maintain stable switching characteristics and minimize crosstalk between NPN and PNP sections.

Is the ACX124EUQ suitable for 3.3 V logic interfacing?

Yes - its VI(on) threshold is guaranteed at ±3.0 V (NPN: +3.0 V, PNP: –3.0 V) with VI(off) ≤ ±0.5 V, making it fully compatible with 3.3 V CMOS outputs. The device draws ≤ ±0.36 mA input current at VI = ±5 V, ensuring minimal loading on low-drive-strength microcontrollers without requiring buffer stages.