onsemi BC182B

Overview

BC182B from Fairchild Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for low-power amplification and switching up to 100 mA collector current, with V_CEO = 50 V, h_FE = 40–80 at I_C = 100 mA, and f_T = 150 MHz - used in audio preamplifiers, signal conditioning stages, and discrete logic interface circuits.

For engineers reviewing the BC182B datasheet, pinout, applications, or equivalent options, key selection criteria include its TO-92 package compatibility, DC current gain range under defined bias conditions, saturation voltage at 100 mA, thermal derating behavior, and noise figure at low collector current.

Technical Context

The BC182B operates as a silicon NPN BJT with fixed emitter-base and collector-base junction structures optimized for linear amplification and moderate-speed switching. Its h_FE variation across I_C (10 µA to 100 mA) and V_CE = 5 V reflects process-controlled beta spread, while f_T = 150 MHz confirms usable RF capability up to low-VHF bands.

Thermal design relies on R_θJA = 357 °C/W and PD = 350 mW at T_A = 25 °C, with linear derating of 2.8 mW/°C above ambient. Cob = 5 pF at V_CE = 10 V supports stable high-frequency biasing in tuned amplifier configurations.

Key Specifications

Pinout & Package

BC182B is housed in a standard through-hole TO-92 package with 3 leads: Collector (Lead 1), Base (Lead 2), Emitter (Lead 3). The package provides mechanical robustness and thermal path via leadframe conduction; no internal heatsink pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose amplifier applications.

Compared with BC182B, BC547B offers superior gain-bandwidth trade-off but reduced collector-emitter standoff, while 2N3904 delivers broader availability and higher f_T at the cost of critical V_CEO margin - making BC182B optimal for 50 V tolerant, cost-sensitive linear amplification.

Availability

BC182B is available at Aetrix Electronics and suitable for audio signal conditioning, discrete logic interfacing, low-frequency oscillator design, and relay driver circuits requiring stable component supply and long-term obsolescence management.

Supply support for BC182B 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 devices before its acquisition by ON Semiconductor in 2016.

The BC182B belongs to Fairchild's legacy general-purpose BJT family, engineered for cost-effective, reliable amplification and switching in consumer, industrial, and educational electronics.

FAQ

What is the maximum collector current rating for BC182B?

The BC182B has a continuous collector current rating of 100 mA at T_A = 25 °C. Operation above this value risks thermal runaway or permanent degradation. Derating is required per the 2.8 mW/°C thermal coefficient when ambient exceeds 25 °C. Always verify actual power dissipation using V_CE × I_C in the final circuit layout before committing to BC182B in high-duty-cycle applications.

Does BC182B support high-frequency amplification?

Yes, BC182B supports small-signal amplification up to approximately 50 MHz due to its f_T = 150 MHz and Cob = 5 pF. However, usable gain drops rapidly above 10 MHz in common-emitter configurations without neutralization or careful layout. It is not intended for RF power amplification but performs well in VHF receiver front-ends and broadband preamplifiers where gain flatness is secondary to noise and linearity.

What is the pin configuration of BC182B in TO-92 package?

The BC182B uses standard TO-92 pinout: Lead 1 = Collector, Lead 2 = Base, Lead 3 = Emitter (flat side facing viewer, leads down). This matches JEDEC TO-92 outline and is identical to BC547, 2N3904, and other NPN variants in the same package. No alternate pinouts exist for BC182B - always verify orientation using the datasheet's dimensional drawing before PCB layout.

Can BC182B replace BC107 or BC108 in existing designs?

BC182B is not a direct replacement for BC107 or BC108 due to differences in h_FE range (BC107: 110–450), V_CEO (BC107: 45 V), and f_T (BC107: 250 MHz). While all are NPN TO-92 transistors, substituting BC182B may cause gain compression or instability in high-beta-critical circuits. Verify bias point stability and frequency response before retrofitting BC182B into BC107/BC108 designs.

What is the typical noise figure of BC182B and at what condition is it measured?

The BC182B has a typical noise figure of 10 dB, measured at V_CE = 5 V, I_C = 0.2 mA, R_S = 2 kΩ, f = 1 kHz, and BW = 200 Hz. This value reflects its suitability for low-current, high-impedance input stages such as electret microphone preamplifiers. Noise performance degrades significantly above 1 mA collector current, so optimal low-noise operation requires careful biasing near the specified test condition.