Diodes Incorporated AC847BWQ-7

Overview

AC847BWQ-7 from Diodes Incorporated is an AEC-Q101-qualified NPN bipolar junction transistor in SOT323 package, rated for V_CEO = 45 V, I_C = 100 mA continuous, and h_FE = 200–450 (Group B), designed for automotive switching and audio-frequency amplifier circuits.

For engineers reviewing the AC847BWQ-7 datasheet, AC847BWQ-7 pinout, AC847BWQ-7 application, or AC847BWQ-7 equivalent, key selection criteria include its AEC-Q101 qualification, low V_CE(SAT) (90–250 mV at I_C = 10 mA), f_T ≥ 100 MHz, ESD HBM rating of 4 kV, and SOT323 footprint compatibility with automated insertion.

Technical Context

This transistor operates as a general-purpose NPN switch or linear amplifier with defined gain grouping (B-band), specified under pulsed test conditions (≤300 µs, ≤2% duty cycle) to ensure stable DC current gain across temperature (−50°C to +150°C). Its breakdown voltages-V_CBO = 50 V, V_CEO = 45 V, V_EBO = 6 V-support robust operation in 12 V automotive subsystems.

Thermal performance is characterized by R_θJA = 625 °C/W on minimum pad layout, limiting usable power dissipation to 200 mW at T_A = 25°C, with derating to zero at 150°C ambient. Output capacitance (C_OBO = 3–4.5 pF) and noise figure (NF = 10 dB at 1 kHz) are optimized for AF signal integrity.

Key Specifications

Pinout & Package

SOT323 is a surface-mount, 3-pin plastic package with 0.65 mm lead pitch, 2.15 mm × 2.10 mm body, and 0.95 mm height, optimized for high-density automotive PCB layouts and reflow soldering.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN transistor applications.

Compared with BC847BW,115 and MMBT3904LT1G, AC847BWQ-7 uniquely combines AEC-Q101 compliance, 45 V V_CEO, and guaranteed low V_CE(SAT) in a single-source automotive-qualified part-critical for safety-relevant switching in door modules and BCMs.

Availability

AC847BWQ-7 is available at Aetrix Electronics and suitable for automotive door modules, infotainment preamplifiers, and body control unit load drivers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AC847BWQ-7 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, headquartered in Plano, Texas, with design, manufacturing, and sales operations across Asia, Europe, and the Americas.

The AC847BWQ series belongs to Diodes' automotive-qualified small-signal transistor product line, engineered specifically for reliable switching and amplification in harsh-environment vehicle subsystems operating from −40°C to +125°C.

FAQ

Is AC847BWQ-7 suitable for linear amplification in automotive audio circuits?

Yes. With h_FE = 200–450 at I_C = 2 mA and V_CE = 5 V, plus a noise figure of 10 dB at 1 kHz, it supports low-distortion preamplification in head units and display backlight drivers. Its gain stability over −50°C to +150°C ensures consistent performance across vehicle cabin temperatures.

What is the maximum allowable ambient temperature for continuous 100 mA operation?

At I_C = 100 mA, power dissipation reaches ~25 mW in saturation (V_CE(SAT) ≈ 250 mV). Given R_θJA = 625 °C/W, junction temperature rise is ~15.6°C above ambient. With T_J(max) = 150°C, continuous operation is safe up to ~134°C ambient-well beyond automotive under-hood requirements (max 125°C).

Does AC847BWQ-7 require special PCB layout considerations for thermal management?

No. Its 200 mW absolute maximum power rating assumes standard 1 oz copper on FR-4 with minimum recommended SOT323 pad layout. No thermal vias or copper pours are required for typical 100 mA switching. Derating begins linearly above 25°C ambient, reaching zero dissipation at 150°C.

Can AC847BWQ-7 be used as a direct replacement for BC847B in existing designs?

Electrically and physically compatible-same SOT323 footprint, pinout, and B-band h_FE range-but AC847BWQ-7 adds AEC-Q101 qualification, 4 kV HBM ESD, and automotive-compliant green materials. Replacement is valid if the application demands automotive reliability; no circuit redesign is needed.