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

onsemi BCW30

Name: BCW30
Brand: onsemi
SKU: BCW30
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BCW30

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: BCW30.pdf

Description:: TRANS PNP 32V 0.5A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Inventory:2,925

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Product details

Overview

BCW30 from Fairchild Semiconductor is a PNP general-purpose amplifier transistor rated for -32 V V_CEO, -500 mA continuous collector current, and 350 mW power dissipation in SOT-23 package; used in medium-power audio preamplifiers and low-speed switching circuits.

For engineers reviewing the BCW30 datasheet, pinout, applications, or equivalent options, key selection criteria include its -32 V breakdown rating, h_FE range of 215–500 at -2 mA, -0.3 V V_CE(sat) at -10 mA/-0.5 mA drive, -0.6 to -0.7 V V_BE(on), and 10 dB noise figure at 1 kHz.

Technical Context

The BCW30 is a silicon PNP bipolar junction transistor optimized for linear amplification and saturated switching in low-to-medium power analog and digital circuits. Its design supports operation up to +150°C junction temperature with thermal resistance R_θJA = 357°C/W.

It exhibits consistent DC current gain (h_FE) across -2 mA to -100 mA collector currents and maintains low saturation voltage under moderate base drive, enabling efficient use in battery-powered signal conditioning and discrete logic interface stages.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	-32 V - Maximum safe collector-emitter voltage before breakdown in open-base configuration
I_C (continuous)	-500 mA - Continuous collector current handling capacity without thermal derating
P_D	350 mW - Total power dissipation at 25°C ambient; derates 2.8 mW/°C above that
h_FE	215–500 - DC current gain at V_CE = -5 V, I_C = -2 mA; enables predictable biasing in amplifier designs
V_CE(sat)	-0.3 V - Low saturation voltage at I_C = -10 mA / I_B = -0.5 mA; reduces conduction loss in switch mode
NF	10 dB - Noise figure at 1 kHz, 2 kΩ source impedance; suitable for low-noise preamp stages

Pinout & Package

SOT-23 plastic surface-mount package with 3-pin configuration: compact footprint (2.90 × 1.30 mm), gull-wing leads, and JEDEC-standard thermal profile. Marking "C2" identifies BCW30 on device top.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control terminal for forward-biased PNP operation; requires negative base current relative to emitter
2	Emitter	Current source terminal in PNP configuration; typically connected to higher potential rail
3	Collector	Current sink terminal; delivers amplified or switched output current to load

Key Features

Feature	Design Value
High h_FE range	215–500 ensures stable small-signal amplification and reliable switching with minimal base drive
Low V_CE(sat)	-0.3 V at rated I_C/I_B reduces power loss and self-heating in switching applications
Low-noise performance	10 dB NF at 1 kHz supports use in sensitive analog front-ends and audio signal paths
Robust thermal rating	Junction temperature range of -55°C to +150°C allows deployment in industrial and automotive ambient environments

Applications

Audio Preamp Stage	Discrete Logic Level Shifter
Use Scenario: Amplifying microphone-level signals in portable audio recorders before ADC input. IC Role / Device Role / Timing Role: PNP small-signal amplifier providing voltage gain and impedance matching. Use Value: 215–500 h_FE and 10 dB noise figure ensure clean signal amplification without introducing audible noise.	Use Scenario: Converting 3.3 V logic outputs to interface with legacy 5 V TTL inputs. IC Role / Device Role / Timing Role: Discrete level-shifting switch operating in common-emitter configuration. Use Value: -0.3 V V_CE(sat) and -32 V V_CEO enable fast, low-loss translation with margin against supply transients.
Low-Power Relay Driver	Current Mirror Reference
Use Scenario: Driving coil current for sub-100 mA electromagnetic relays in programmable logic controllers. IC Role / Device Role / Timing Role: Saturated PNP switch controlling relay coil ground path. Use Value: -500 mA I_C rating and 350 mW power dissipation support sustained relay actuation without heatsinking.	Use Scenario: Building matched current sources in precision analog sensor conditioning circuits. IC Role / Device Role / Timing Role: Active component in two-transistor current mirror topology. Use Value: Tight h_FE consistency and low V_BE(on) variation (-0.6 to -0.7 V) improve mirror accuracy and temperature stability.

Audio Preamp Stage

Discrete Logic Level Shifter

Use Scenario: Amplifying microphone-level signals in portable audio recorders before ADC input.

IC Role / Device Role / Timing Role: PNP small-signal amplifier providing voltage gain and impedance matching.

Use Value: 215–500 h_FE and 10 dB noise figure ensure clean signal amplification without introducing audible noise.

Use Scenario: Converting 3.3 V logic outputs to interface with legacy 5 V TTL inputs.

IC Role / Device Role / Timing Role: Discrete level-shifting switch operating in common-emitter configuration.

Use Value: -0.3 V V_CE(sat) and -32 V V_CEO enable fast, low-loss translation with margin against supply transients.

Low-Power Relay Driver

Current Mirror Reference

Use Scenario: Driving coil current for sub-100 mA electromagnetic relays in programmable logic controllers.

IC Role / Device Role / Timing Role: Saturated PNP switch controlling relay coil ground path.

Use Value: -500 mA I_C rating and 350 mW power dissipation support sustained relay actuation without heatsinking.

Use Scenario: Building matched current sources in precision analog sensor conditioning circuits.

IC Role / Device Role / Timing Role: Active component in two-transistor current mirror topology.

Use Value: Tight h_FE consistency and low V_BE(on) variation (-0.6 to -0.7 V) improve mirror accuracy and temperature stability.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC807-40	Higher h_FE (250–630), same SOT-23 package, -45 V V_CEO, -500 mA I_C	Better suited for high-gain, low-drive switching where tighter h_FE tolerance is needed	Select BC807-40 when higher minimum gain or improved voltage margin is required
MMBT3906	Lower power rating (310 mW), identical V_CEO (-40 V), h_FE 100–300, same pinout	Preferred for ultra-low-power bias networks where thermal headroom is constrained	Choose MMBT3906 for space-constrained, low-duty-cycle biasing where 310 mW suffices

Compared with BCW30, BC807-40 offers higher guaranteed gain and voltage margin but shares identical SOT-23 footprint and function; MMBT3906 trades 40 mW power capability for broader industry availability and lower cost in low-stress bias roles.

Availability

BCW30 is available at Aetrix Electronics and suitable for audio preamplifiers, discrete logic level shifters, and low-power relay drivers requiring stable component supply and long-term industrial sourcing.

Supply support for BCW30 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 leading designer of discrete semiconductors and power management ICs, acquired by ON Semiconductor in 2016; known for robust, widely adopted bipolar and MOSFET product families.

The BCW30 belongs to Fairchild's general-purpose PNP transistor series engineered for cost-sensitive, medium-power analog amplification and switching in consumer, industrial, and automotive auxiliary circuits.

FAQ

What is the maximum collector-emitter voltage rating for BCW30?

The BCW30 has a maximum collector-emitter voltage rating of -32 V under open-base conditions (V_CEO). This value is confirmed in the Absolute Maximum Ratings table and verified in the Electrical Characteristics section for V(BR)_CEO at I_C = -2.0 mA. Exceeding this voltage risks irreversible junction breakdown. The BCW30 must be operated within this limit in all circuit configurations.

Does BCW30 have a specified noise figure, and under what conditions?

Yes, the BCW30 has a specified noise figure of 10 dB, measured at V_CE = -5.0 V, I_C = -200 µA, R_S = 2.0 kΩ, f = 1.0 kHz, and BW = 200 Hz. This parameter is explicitly listed in the Small Signal Characteristics table of the official Fairchild datasheet. The BCW30's 10 dB noise figure supports its use in low-noise preamplifier stages where signal integrity is critical.

What is the pin configuration of BCW30 in the SOT-23 package?

The BCW30 uses standard SOT-23 pinout: Pin 1 is Base, Pin 2 is Emitter, and Pin 3 is Collector - confirmed by the "1. Base 2. Emitter 3. Collector" notation and diagram in the Fairchild BCW30 datasheet. This arrangement is consistent across all SOT-23-packaged PNP transistors from Fairchild's BCW series. Correct orientation is essential for functional circuit operation of the BCW30.

What is the DC current gain (h_FE) range for BCW30, and at what test conditions?

The BCW30 has a DC current gain (h_FE) range of 215 to 500, specified at V_CE = -5.0 V and I_C = -2.0 mA. This is documented in the On Characteristics section of the Fairchild datasheet. The wide h_FE spread reflects process variation but remains usable for bias design with appropriate emitter degeneration. Circuit designs using BCW30 should accommodate this full range.

Is BCW30 suitable for switching applications, and what saturation voltage does it exhibit?

Yes, BCW30 is suitable for switching applications, with a specified collector-emitter saturation voltage (V_CE(sat)) of -0.3 V at I_C = -10 mA and I_B = -0.5 mA. This low saturation voltage minimizes conduction loss and self-heating during active switching. When used as a saturated switch, the BCW30 delivers predictable turn-on behavior and efficient power control in discrete driver stages.

BCW30 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 500 mA

Voltage - Collector Emitter Breakdown (Max):: 32 V

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 500µA, 10mA

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 215 @ 2mA, 5V

Power - Max:: 350 mW

Frequency - Transition:: -

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

BCW30 FAQ

1.How can I place an order for BCW30 through Aetrix?

Please submit a Request for Quotation (RFQ) for BCW30 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 BCW30 reliable?

The price and inventory of BCW30 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BCW30 is usually 5 days.

3.What payment methods are accepted for BCW30?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BCW30 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BCW30?

BCW30 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BCW30 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 BCW30?

For technical support, including BCW30 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BCW30 requirements.

6.How does Aetrix verify that BCW30 is sourced from the original manufacturer or authorized distributors?

All BCW30 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 BCW30 meets industry standards.

7.What is the process for return or replacement of BCW30?

All BCW30 units undergo pre-shipment inspection (PSI). If there is an issue with BCW30, 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 BCW30 part is unused and in its original packaging.

Return procedure for BCW30:

1.Submit a request within 90 days.

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

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