onsemi BC184L

Overview

BC184L from Fairchild Semiconductor is a silicon NPN small-signal transistor in TO-92 package, rated for 30 V V_CEO, 500 mA I_C, and 350 mW P_C at T_a = 25°C, with minimum h_FE of 130 at I_C = 100 mA - used in low-power audio preamplifiers, signal switching, and sensor interface stages.

For engineers reviewing the BC184L datasheet, pinout, applications, or equivalent options, key selection considerations include its 150 MHz f_T, 5 pF C_OB, 4 dB noise figure at 1 kHz, V_BE(sat) of 1.2 V at I_C = 100 mA, and TO-92 mechanical compatibility with legacy through-hole designs.

Technical Context

The BC184L operates as a general-purpose amplifying and switching device with DC current gain (h_FE) ranging from 100 to 130 at I_C = 100 mA and 450–900 at I_C = 2 mA, supporting both linear amplification and saturated switching modes. Its 150 MHz f_T enables stable operation up to mid-VHF frequencies under specified bias conditions.

Thermal design is constrained by a maximum junction temperature of 150°C and 350 mW power dissipation at ambient 25°C, with thermal resistance θ_JA implied by package geometry and mounting. The device exhibits low leakage: I_CBO ≤ 15 nA at V_CB = 30 V and I_EBO ≤ 15 nA at V_EB = 3 V.

Key Specifications

Pinout & Package

BC184L is housed in a standard TO-92 plastic package with 3 leads: Emitter (pin 1), Collector (pin 2), Base (pin 3), compliant with JEDEC TO-92 outline dimensions (max height 4.58 mm, body width 3.60 mm).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC184L, BC547B offers greater voltage safety margin and higher typical gain, while 2N3904 provides superior high-frequency response but looser h_FE tolerance at 100 mA - all three share TO-92 packaging and direct PCB interchangeability in non-critical gain/voltage designs.

Availability

BC184L is available at Aetrix Electronics and suitable for audio preamplifiers, sensor interface circuits, and relay driver modules requiring stable component supply across industrial control, instrumentation, and legacy consumer electronics programs.

Supply support for BC184L 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

Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete devices, acquired by ON Semiconductor in 2016.

The BC184L belongs to Fairchild's legacy silicon NPN transistor family designed for general-purpose linear amplification and switching in cost-sensitive, through-hole assembled systems.

FAQ

What is the maximum collector current rating for BC184L?

The BC184L has a maximum DC collector current rating of 500 mA, as specified in its Absolute Maximum Ratings table at T_C = 25°C. This rating assumes adequate PCB copper area or heatsinking to maintain junction temperature below 150°C. At higher ambient temperatures or continuous operation, derating is required per the thermal characteristics in the BC184L datasheet.

Does BC184L have a guaranteed minimum hFE at high collector current?

Yes, the BC184L guarantees h_FE ≥ 130 at V_CE = 5 V and I_C = 100 mA, as stated in both the Electrical Characteristics table and the device summary. This minimum gain ensures predictable saturation behavior in switching applications and stable bias points in Class-A amplifiers using the BC184L.

What is the noise figure of BC184L and under what conditions is it measured?

The BC184L has a noise figure of 4 dB, measured at V_CE = 5 V, I_C = 200 mA, source resistance R_G = 2 kΩ, and frequency f = 1 kHz. This value reflects its suitability for low-noise amplification of audio and sensor signals where signal integrity at sub-MHz frequencies is critical - a key specification distinguishing BC184L from generic switching transistors.

Is BC184L compatible with standard TO-92 sockets and assembly processes?

Yes, BC184L uses the industry-standard TO-92 package with pin 1 (Emitter), pin 2 (Collector), pin 3 (Base) configuration and JEDEC-compliant dimensions (e.g., 3.60 ±0.20 mm body width). It is fully compatible with automated through-hole insertion, wave soldering, and manual prototyping sockets designed for TO-92 transistors like BC547 or 2N3904.

What is the output capacitance (C_OB) of BC184L and why does it matter?

The BC184L has an output capacitance C_OB of 5 pF, measured at V_CE = 10 V and f = 1 MHz. This low capacitance limits Miller effect in high-frequency amplifiers and preserves bandwidth in RF coupling or oscillator tank circuits - making BC184L more suitable than higher-C_OB transistors for applications up to ~20 MHz where parasitic loading must be minimized.