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Home > Products > Discrete Semiconductor Products > Transistors > Bipolar (BJT) > Single Bipolar Transistors

onsemi BC212B_D27Z

Name: BC212B_D27Z
Brand: onsemi
SKU: BC212B_D27Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC212B_D27Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Datasheet:: BC212B_D27Z.pdf

Description:: TRANS PNP 50V 0.1A TO-92-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC212B_D27Z from Fairchild Semiconductor is a PNP general-purpose bipolar junction transistor (BJT) designed for low-power amplification and switching at collector currents up to 100 mA. It features V_CEO = 50 V, V_CBO = 60 V, h_FE = 40–60 (at I_C = 2 mA), V_CE(sat) = 0.6 V (I_C = 100 mA, I_B = 5 mA), and TO-92 package. It is used in discrete audio preamplifier stages and signal-level switching circuits.

For engineers reviewing the BC212B_D27Z datasheet, pinout, applications, or equivalent options, key selection considerations include its PNP polarity, DC current gain range, saturation voltage under defined drive conditions, thermal resistance (R_θJA = 357 °C/W), and suitability for linear amplification versus saturated switching operation.

Technical Context

The BC212B_D27Z operates as a silicon PNP BJT with a maximum junction temperature of 150°C and specified performance at T_C = 25°C. Its off-state leakage (I_CBO ≤ 15 nA at V_CB = 30 V) and noise figure (NF = 10 dB at I_C = 200 µA, f = 1 kHz) support low-noise analog signal handling.

It exhibits small-signal current gain (h_fe) of 200–400 at V_CE = 5 V, I_C = 2 mA, f = 1 kHz, and output capacitance (C_ob) of 6 pF at V_CE = 10 V, f = 1 MHz - parameters critical for bandwidth-limited amplifier design and stability analysis.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	50 V - Maximum safe collector-emitter voltage before breakdown under open-base condition.
h_FE	40–60 - DC current gain range at V_CE = 5 V, I_C = 2 mA; determines base drive requirement for switching.
V_CE(sat)	0.6 V - Collector-emitter voltage drop when fully saturated (I_C = 100 mA, I_B = 5 mA); impacts conduction loss in switch mode.
P_D	350 mW - Maximum continuous power dissipation at 25°C ambient; derates 2.8 mW/°C above that temperature.
R_θJA	357 °C/W - Junction-to-ambient thermal resistance in free-air; defines temperature rise per watt dissipated.
C_ob	6 pF - Output capacitance at V_CE = 10 V, 1 MHz; limits high-frequency gain and affects amplifier stability.

Pinout & Package

BC212B_D27Z is housed in a through-hole TO-92 package with standard lead configuration: Lead 1 = Collector, Lead 2 = Base, Lead 3 = Emitter (viewed from flat side, leads down).

Pin/Terminal	Circuit Role	Design Meaning
1 (Collector)	Main current sink terminal	Connected to load or higher-voltage rail in PNP switching; voltage rating (V_CEO = 50 V) sets upper limit for circuit node swing.
2 (Base)	Control input for minority-carrier injection	Requires negative bias relative to emitter to turn on; base-emitter on voltage (V_BE(on) = 0.6–0.72 V) defines threshold for conduction.
3 (Emitter)	Current source terminal	Typically tied to positive supply in PNP common-emitter configuration; V_EBO = 5 V limits reverse bias tolerance.

Key Features

Feature	Design Value
Low-noise amplification	NF = 10 dB at I_C = 200 µA, enabling use in microphone preamps and sensor signal conditioning.
Stable h_fe over operating range	h_fe = 200–400 at 1 kHz supports predictable AC gain in small-signal stages.
Controlled saturation behavior	V_CE(sat) ≤ 0.6 V ensures minimal voltage drop and heat generation during switching.
Robust thermal margin	T_J(max) = 150°C and R_θJC = 125 °C/W allow reliable operation in enclosed industrial enclosures.

Applications

Audio Preamp Stage	Level-Shifting Switch
Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors in battery-powered voice recorders. IC Role / Device Role / Timing Role: PNP BJT configured in common-emitter topology to provide voltage gain with inverted output polarity. Use Value: Low noise figure (10 dB) and stable h_fe ensure clean signal amplification without introducing audible hiss or distortion.	Use Scenario: Driving a 5 V logic-controlled relay coil from a 3.3 V microcontroller GPIO pin via level translation. IC Role / Device Role / Timing Role: Saturated PNP switch sinking current from relay coil to ground when base is pulled low. Use Value: V_CE(sat) ≤ 0.6 V minimizes power loss and coil heating, while V_CEO = 50 V provides ample margin against inductive kickback.
Current Mirror Reference	Discrete Oscillator Core
Use Scenario: Forming matched current sources in analog front-end ICs where integrated BJTs are unavailable or insufficiently matched. IC Role / Device Role / Timing Role: One half of a PNP current mirror pair biased at I_C = 2 mA to replicate reference current in precision analog circuits. Use Value: Tight h_FE consistency (40–60) and low I_CBO (≤15 nA) reduce mirror ratio error and temperature drift.	Use Scenario: Active device in a Colpitts oscillator generating 1–10 MHz clock signals for non-critical timing functions. IC Role / Device Role / Timing Role: Gain element sustaining oscillation via feedback network; C_ob = 6 pF contributes to resonant tank loading. Use Value: Predictable Cob and h_fe enable stable frequency tuning and low phase noise in discrete RF oscillator designs.

Audio Preamp Stage

Level-Shifting Switch

Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors in battery-powered voice recorders.

IC Role / Device Role / Timing Role: PNP BJT configured in common-emitter topology to provide voltage gain with inverted output polarity.

Use Value: Low noise figure (10 dB) and stable h_fe ensure clean signal amplification without introducing audible hiss or distortion.

Use Scenario: Driving a 5 V logic-controlled relay coil from a 3.3 V microcontroller GPIO pin via level translation.

IC Role / Device Role / Timing Role: Saturated PNP switch sinking current from relay coil to ground when base is pulled low.

Use Value: V_CE(sat) ≤ 0.6 V minimizes power loss and coil heating, while V_CEO = 50 V provides ample margin against inductive kickback.

Current Mirror Reference

Discrete Oscillator Core

Use Scenario: Forming matched current sources in analog front-end ICs where integrated BJTs are unavailable or insufficiently matched.

IC Role / Device Role / Timing Role: One half of a PNP current mirror pair biased at I_C = 2 mA to replicate reference current in precision analog circuits.

Use Value: Tight h_FE consistency (40–60) and low I_CBO (≤15 nA) reduce mirror ratio error and temperature drift.

Use Scenario: Active device in a Colpitts oscillator generating 1–10 MHz clock signals for non-critical timing functions.

IC Role / Device Role / Timing Role: Gain element sustaining oscillation via feedback network; C_ob = 6 pF contributes to resonant tank loading.

Use Value: Predictable Cob and h_fe enable stable frequency tuning and low phase noise in discrete RF oscillator designs.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC557B	Higher h_FE (110–220), same TO-92, V_CEO = 45 V	Better suited for low-drive switching; lower V_CEO limits high-voltage headroom	Prefer BC557B when higher gain and lower base current are needed, but verify V_CEO margin in target circuit.
2N3906	V_CEO = 40 V, h_FE = 100–300, same pinout, slightly higher Cob (8 pF)	More widely available; higher gain reduces base resistor sizing sensitivity	Choose 2N3906 for cost-sensitive production where tighter gain tolerance is acceptable and voltage stress is <40 V.

Compared with BC212B_D27Z, BC557B offers higher DC gain but reduced collector-emitter voltage rating, while 2N3906 provides broader gain distribution and higher availability - both require verification of V_CEO and thermal derating in the final layout.

Availability

BC212B_D27Z is available at Aetrix Electronics and suitable for audio preamplifiers, discrete switching circuits, current mirror references, and low-frequency oscillator designs requiring stable component supply and legacy semiconductor compatibility.

Supply support for BC212B_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 designer and manufacturer of analog and discrete semiconductors, acquired by ON Semiconductor in 2016. Known for robust process technologies and broad legacy product coverage.

The BC212B_D27Z belongs to Fairchild's general-purpose PNP BJT family, engineered for cost-effective linear amplification and switching in consumer, industrial, and instrumentation applications where reliability and parameter consistency are prioritized over ultra-high speed.

FAQ

What is the pin configuration of BC212B_D27Z?

The BC212B_D27Z uses a TO-92 package with pin 1 = Collector, pin 2 = Base, and pin 3 = Emitter when viewed from the flat side with leads pointing downward. This configuration is standardized across Fairchild's BC212 series and matches JEDEC TO-92 mechanical specifications. Always confirm orientation using the datasheet diagram before PCB layout.

Is BC212B_D27Z suitable for switching applications?

Yes, BC212B_D27Z is suitable for low-speed switching applications up to ~100 kHz due to its V_CE(sat) = 0.6 V at I_C = 100 mA and I_B = 5 mA. Its h_FE range (40–60) allows predictable base drive calculation. However, it is not optimized for high-frequency or high-efficiency switching - consider modern MOSFETs for >1 MHz or <0.2 V drop requirements.

What is the maximum operating temperature for BC212B_D27Z?

The BC212B_D27Z has a maximum junction temperature (T_J) of 150°C and an operating junction temperature range of –55°C to +150°C. Ambient operation is limited by thermal derating: power dissipation must be reduced by 2.8 mW per °C above 25°C ambient, based on R_θJA = 357 °C/W. PCB copper area and airflow directly impact real-world thermal performance.

Does BC212B_D27Z have a specified noise figure?

Yes, BC212B_D27Z has a specified noise figure of 10 dB at V_CE = 5 V, I_C = 200 µA, f = 1 kHz, R_G = 2 kΩ, and BW = 200 Hz. This value is measured under standardized small-signal conditions and confirms suitability for low-noise preamplifier stages - notably in electret microphone interfaces and sensor front-ends where signal integrity is critical.

How does BC212B_D27Z compare to BC212A and BC212C?

The BC212B_D27Z is the mid-gain variant in the BC212 family: BC212A has h_FE = 20–40, BC212B has h_FE = 40–60, and BC212C has h_FE = 60–100. All share identical absolute maximum ratings, package, pinout, and electrical characteristics except h_FE binning. BC212B_D27Z is selected when moderate, predictable gain is required without excessive variation or overdesign.

BC212B_D27Z Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA) Formed Leads

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 100 mA

Voltage - Collector Emitter Breakdown (Max):: 50 V

Vce Saturation (Max) @ Ib, Ic:: 600mV @ 5mA, 100mA

Current - Collector Cutoff (Max):: 15nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 60 @ 2mA, 5V

Power - Max:: 350 mW

Frequency - Transition:: -

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

BC212B_D27Z FAQ

1.How can I place an order for BC212B_D27Z through Aetrix?

Please submit a Request for Quotation (RFQ) for BC212B_D27Z on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for BC212B_D27Z reliable?

The price and inventory of BC212B_D27Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC212B_D27Z is usually 5 days.

3.What payment methods are accepted for BC212B_D27Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC212B_D27Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC212B_D27Z?

BC212B_D27Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC212B_D27Z order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for BC212B_D27Z?

For technical support, including BC212B_D27Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC212B_D27Z requirements.

6.How does Aetrix verify that BC212B_D27Z is sourced from the original manufacturer or authorized distributors?

All BC212B_D27Z products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BC212B_D27Z meets industry standards.

7.What is the process for return or replacement of BC212B_D27Z?

All BC212B_D27Z units undergo pre-shipment inspection (PSI). If there is an issue with BC212B_D27Z, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The BC212B_D27Z part is unused and in its original packaging.

Return procedure for BC212B_D27Z:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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