onsemi BC214

Overview

BC214 from Fairchild Semiconductor is a PNP general-purpose bipolar junction transistor (BJT) designed for amplification and switching in low-power analog and digital circuits, with V_CEO = −30 V, I_C = −500 mA, h_FE = 100–400 at I_C = −10 µA to −100 mA, f_T = 200 MHz, and TO-92 package. It serves in audio preamplifiers, signal inversion stages, and discrete logic-level switching.

For engineers reviewing the BC214 datasheet, pinout, applications, or equivalent options, key selection considerations include its PNP polarity, −30 V V_CEO rating, −500 mA continuous collector current capability, thermal resistance of 200 °C/W (Junction-to-Ambient), and suitability for linear amplification and saturated switching below 300 mA load.

Technical Context

The BC214 operates as a silicon PNP BJT with epitaxial planar construction, optimized for general-purpose linear amplification and switching. Its DC current gain (h_FE) varies from 100 at I_C = −10 µA to 120 at I_C = −100 mA, and saturation voltage V_CE(sat) is −0.25 V at I_C = −10 mA / I_B = −0.5 mA.

Small-signal performance includes f_T = 200 MHz at V_CE = −5 V / I_C = −10 mA and noise figure NF = 2.0 dB at 15.7 kHz, supporting low-noise audio and RF front-end use. Output capacitance C_OB is 10 pF at V_CB = −10 V, confirming suitability for frequencies up to mid-VHF range.

Key Specifications

Pinout & Package

BC214 is housed in a through-hole TO-92 package (JEDEC TO-92 variant), with standardized lead configuration: Lead 1 = Collector, Lead 2 = Base, Lead 3 = Emitter. Package dimensions are fully specified per Fairchild Rev. A drawing, including 14.47 mm overall length and 3.60 mm body width.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC214, BC557 offers higher breakdown voltage but reduced current drive, while 2N3906 trades some current headroom (−200 mA vs. −500 mA) for wider supply chain support and tighter h_FE binning-making BC214 optimal for cost-sensitive, medium-current PNP switching where thermal margin matters.

Availability

BC214 is available at Aetrix Electronics and suitable for audio preamplifiers, discrete logic inverters, and LED driver circuits requiring stable component supply, consistent parametric performance, and long-term industrial availability.

Supply support for BC214 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 BC214 belongs to Fairchild's legacy general-purpose bipolar transistor family, engineered for cost-effective, reliable amplification and switching in consumer, industrial, and automotive auxiliary circuits.

FAQ

What is the maximum continuous collector current for BC214?

The BC214 has a maximum continuous collector current (I_C) rating of −500 mA at T_A = 25°C. Derating applies above 25°C at 5.0 mW/°C, and actual sustainable current depends on PCB copper area, ambient temperature, and heatsinking. For reliable long-term operation, design for ≤ −300 mA under typical board conditions. The BC214 datasheet specifies this limit under steady-state DC conditions.

Is BC214 suitable for audio amplifier applications?

Yes, BC214 is suitable for low-noise audio amplifier applications such as microphone preamplifiers and line-level buffers. Its noise figure of 2.0 dB at 15.7 kHz, combined with h_FE ≥ 140 at I_C = −2 mA and f_T = 200 MHz, supports high-fidelity gain stages with minimal added noise. The BC214 performs best in common-emitter or emitter-follower configurations with proper biasing and decoupling.

What is the pin configuration of BC214 in TO-92 package?

The BC214 uses standard TO-92 pinout: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter (viewed with flat side facing outward and leads pointing down). This matches JEDEC TO-92 mechanical specification and is identical to BC557 and 2N3906. Always verify orientation using the BC214 datasheet diagram before PCB layout, as incorrect mounting reverses polarity functionality.

Does BC214 have a documented replacement or drop-in alternative?

No official drop-in replacement is documented for BC214. While BC557 and 2N3906 share the same TO-92 package and PNP polarity, they differ in absolute maximum ratings and gain profiles. BC214's −500 mA I_C and −30 V V_CEO are not fully matched by either. Substitution requires circuit revalidation, especially in high-current or low-noise designs relying on BC214-specific parameters.

What is the thermal resistance of BC214, and how does it affect PCB layout?

The BC214 has R_θJA = 200 °C/W (Junction-to-Ambient) and R_θJC = 83.3 °C/W (Junction-to-Case). With 625 mW max power dissipation at 25°C, even modest power (e.g., 300 mW) raises junction temperature by ~60°C above ambient. To maintain reliability, use ≥ 1 cm² of 1-oz copper pour connected to the collector pad, avoid enclosed enclosures, and consider forced airflow if operating near thermal limits. These values are measured per BC214 datasheet Rev. A.