onsemi BC212_D27Z

Overview

BC212_D27Z from Fairchild Semiconductor is a PNP bipolar junction transistor designed for general-purpose amplification and switching at DC collector currents up to 300 mA. It features a 50 V V_CEO, 60 V V_CBO, DC current gain (h_FE) of 40–60 at I_C = 2 mA, and operates across –55 °C to +150 °C junction temperature range. It is commonly used in low-frequency signal amplification stages of consumer audio preamps and discrete logic-level translators.

For engineers reviewing the BC212_D27Z datasheet, pinout, applications, or equivalent options, key selection criteria include its PNP polarity, TO-92 package thermal resistance (R_θJA = 200 °C/W), saturation voltage (V_CE(sat) = 0.6 V @ I_C = 100 mA), and guaranteed h_FE minimum of 40 at low bias - critical for predictable biasing in linear amplifier designs.

Technical Context

The BC212_D27Z is a silicon planar PNP BJT fabricated using Fairchild's Process 68, optimized for stable DC amplification and moderate-speed switching. Its structure supports operation with V_EB(on) = 0.6–0.72 V and V_BE(sat) = 1.4 V at I_C = 100 mA, enabling reliable turn-on in emitter-follower configurations.

Thermal design relies on its R_θJA = 200 °C/W when mounted on a standard FR-4 PCB (1.6" × 1.6" × 0.06"), limiting continuous power dissipation to 625 mW at 25 °C ambient, derating by 5.0 mW/°C above that. Output capacitance (C_ob = 6 pF @ V_CE = 10 V, f = 1 MHz) confirms suitability for audio-band and sub-MHz switching applications.

Key Specifications

Pinout & Package

BC212_D27Z is housed in a through-hole TO-92 package (JEDEC TO-92 variant), with leads arranged in linear order: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter (flat side facing viewer, leads down).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BC377 and BC177, the BC212_D27Z delivers balanced performance: sufficient h_FE for robust biasing without excessive base drive, lower thermal resistance than BC177, and broader availability than BC377 in standard distribution channels - making it optimal for new designs requiring proven reliability and manufacturability.

Availability

BC212_D27Z is available at Aetrix Electronics and suitable for audio pre-amplifier stages, discrete logic level translators, and relay driver circuits requiring stable component supply, long-term obsolescence management, and traceable lot-level documentation.

Supply support for BC212_D27Z 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 components before its acquisition by ON Semiconductor in 2016.

The BC212_D27Z belongs to Fairchild's legacy general-purpose bipolar transistor product line, engineered for cost-effective, reliable amplification and switching in consumer, industrial, and automotive auxiliary circuits.

FAQ

What is the maximum continuous collector current for BC212_D27Z?

The BC212_D27Z supports a maximum continuous DC collector current of 300 mA, as specified in its Absolute Maximum Ratings table. This rating assumes operation within the allowed junction temperature range (–55 °C to +150 °C) and proper PCB thermal management. Exceeding 300 mA may cause irreversible device failure due to thermal runaway or secondary breakdown.

Is BC212_D27Z pin-compatible with BC177 or BC377?

Yes, BC212_D27Z is pin-compatible with BC177 and BC377 in the TO-92 package: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter. However, differences in h_FE, V_BE(sat), and thermal resistance mean electrical behavior will vary - verify bias network and power dissipation margins before substitution in an existing BC212_D27Z design.

What is the typical V_BE(on) of BC212_D27Z at I_C = 2 mA?

The BC212_D27Z exhibits a typical V_BE(on) of 0.72 V at V_CE = 5 V and I_C = 2 mA, with a minimum of 0.6 V under the same conditions. This value is critical for designing accurate base bias resistors in fixed-bias amplifier configurations and must be accounted for alongside h_FE variation to avoid cutoff or saturation errors.

Can BC212_D27Z be used in switching applications above 100 kHz?

No - the BC212_D27Z is not optimized for high-frequency switching. Its transition frequency (f_T) is not specified in the provided datasheet, and measured output capacitance (C_ob = 6 pF) combined with relatively slow minority carrier storage time limits practical use to frequencies below 1 MHz. For >100 kHz switching, consider RF-optimized PNP transistors like MMBT3906 or SOT-23 packaged alternatives.

Does BC212_D27Z meet RoHS requirements?

The BC212_D27Z was manufactured prior to Fairchild's full RoHS transition and is classified as non-RoHS-compliant per its Rev. 1.0.0 datasheet dated September 2007. Aetrix Electronics supplies only fully traceable, documented lots; RoHS-compliant alternatives such as the ON Semiconductor NSS20201MR6T1G (SOT-23 PNP) are available upon request for new designs.