onsemi BC184LC_L34Z

Overview

BC184LC_L34Z from Fairchild Semiconductor is a silicon NPN small-signal transistor in TO-92 package, rated for 30 V V_CEO, 200 mA I_C, and 625 mW P_C, with h_FE ≥ 250 at V_CE = 5 V and I_C = 2 mA; used in audio preamplifier stages, signal switching, and low-power linear amplification circuits.

For engineers reviewing the BC184LC_L34Z datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain consistency across bias points, low noise figure (4 dB at 1 kHz), saturation voltage performance at 100 mA, f_T of 150 MHz, and TO-92 mechanical compatibility in space-constrained analog designs.

Technical Context

This NPN bipolar junction transistor operates in active, saturation, and cutoff regions with defined absolute maximum ratings up to 150°C junction temperature and storage range from –55°C to +150°C. Its small-signal parameters-including h_FE (450–900 typ. at 2 mA), f_T = 150 MHz, and NF = 4 dB-are specified under controlled test conditions (V_CE = 5 V, I_C = 2 mA or 200 mA).

The device exhibits low output capacitance (C_OB = 5 pF at V_CE = 10 V, f = 1 MHz) and tight V_BE(on) distribution (0.55–0.7 V), supporting stable biasing in discrete amplifier topologies and enabling predictable gain staging without thermal runaway in Class-A configurations.

Key Specifications

Pinout & Package

BC184LC_L34Z 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 (14.47 mm length, 4.58 mm width, 3.86 mm height).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC547B and 2N3904, BC184LC_L34Z offers superior h_FE minimum (250) and lower noise (4 dB), making it better suited for low-level analog amplification where gain predictability and SNR matter more than raw bandwidth.

Availability

BC184LC_L34Z is available at Aetrix Electronics and suitable for audio preamplifier stages, signal switching circuits, and RF detector amplifiers requiring stable component supply, consistent h_FE binning, and TO-92 mechanical compatibility.

Supply support for BC184LC_L34Z 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 manufacturer specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.

The BC184LC_L34Z belongs to Fairchild's legacy silicon NPN small-signal transistor family, designed for general-purpose linear amplification, switching, and biasing in consumer, industrial, and communications equipment.

FAQ

What is the maximum collector current rating for BC184LC_L34Z?

The BC184LC_L34Z has a maximum DC collector current (I_C) rating of 200 mA, specified at T_a = 25°C. Derating is required above ambient temperatures per the thermal resistance curve; at 70°C ambient, usable I_C drops to approximately 120 mA to maintain junction temperature ≤150°C. This rating applies to continuous DC operation-not pulsed conditions-where factory consultation is advised.

Does BC184LC_L34Z have a guaranteed minimum h_FE at high current?

Yes, BC184LC_L34Z guarantees h_FE ≥ 130 at V_CE = 5 V and I_C = 100 mA, in addition to h_FE ≥ 250 at I_C = 2 mA. This dual-point specification ensures usable current gain even in medium-current driver applications, unlike many small-signal transistors that only specify h_FE at low bias. The BC184LC_L34Z maintains this performance within its 625 mW power limit.

What is the noise figure of BC184LC_L34Z and under what conditions is it measured?

The BC184LC_L34Z has a noise figure (NF) of 4 dB, measured at V_CE = 5 V, I_C = 200 mA, R_G = 2 kΩ, and f = 1 kHz. This value reflects its suitability for low-noise preamplifier roles where source impedance matches typical electret microphone outputs. NF degrades at higher frequencies and lower collector currents, so optimal noise performance requires operation near the specified test condition.

Is BC184LC_L34Z pin-compatible with other TO-92 NPN transistors like BC547 or 2N3904?

BC184LC_L34Z uses the standard TO-92 pinout (Emitter–Collector–Base, left-to-right when flat side faces user), matching BC547 and 2N3904. However, pin compatibility does not imply functional interchangeability-h_FE, V_CE(sat), and f_T differ significantly. Substituting BC184LC_L34Z into a BC547 design may require bias resistor recalculations due to its lower V_BE(on) (0.55–0.7 V vs. ~0.7 V).

What is the maximum operating junction temperature for BC184LC_L34Z?

The BC184LC_L34Z has a maximum rated junction temperature (T_J) of 150°C, established per Absolute Maximum Ratings. Operation beyond this limit risks permanent degradation of h_FE, increased leakage, or bond wire failure. Thermal design must ensure θ_JA and power dissipation keep T_J ≤150°C; for example, at 500 mW dissipation and θ_JA ≈ 200°C/W, ambient must stay ≤125°C.