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

onsemi BC548BTAR

Name: BC548BTAR
Brand: onsemi
SKU: BC548BTAR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC548BTAR

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: BC548BTAR.pdf

Description:: TRANS NPN 30V 0.1A TO-92-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC548BTAR from ON Semiconductor is a general-purpose NPN epitaxial silicon transistor in TO-92 package, rated for 30 V V_CEO, 100 mA I_C, and 500 mW P_C, with h_FE range of 200–450 (Class B), used in low-voltage switching and small-signal amplification circuits such as audio preamps and logic-level interface stages.

For engineers reviewing the BC548BTAR datasheet, pinout, applications, or equivalent options, key selection considerations include its V_CEO/V_CBO ratings, h_FE classification, saturation voltage at defined I_C/I_B, noise figure, and TO-92 mechanical compatibility across legacy designs.

Technical Context

The BC548BTAR operates as a discrete bipolar junction transistor with epitaxial base construction, optimized for linear amplification and saturated switching in DC-coupled and low-frequency AC applications up to ~300 MHz f_T. Its fixed h_FE Class B bin (200–450) ensures predictable current gain under 2 mA I_C bias at V_CE = 5 V.

It features low V_BE(on) (580–700 mV), moderate Cob (3.5–6.0 pF), and specified noise figure (2.0–10.0 dB at 1 kHz), distinguishing it from low-noise variants (BC549/BC550) and higher-voltage siblings (BC546/BC547). No integrated protection, biasing, or compensation circuitry is present.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	30 V - Maximum collector-emitter voltage before breakdown; defines safe operating range in common-emitter amplifier or switch configurations.
I_C (DC)	100 mA - Continuous collector current limit; determines maximum load drive capability in switching applications.
P_C	500 mW - Total power dissipation at T_A = 25°C; sets thermal derating envelope for PCB layout and heatsinking.
h_FE	200–450 (Class B) - DC current gain at V_CE = 5 V, I_C = 2 mA; enables predictable base drive calculation for saturation or linear operation.
V_CE(sat)	90–250 mV @ I_C = 10 mA, I_B = 0.5 mA - Low saturation voltage ensures minimal conduction loss in digital switching.
f_T	300 MHz - Current gain-bandwidth product; supports RF amplification up to VHF band with appropriate bias and matching.
NF	2.0–10.0 dB @ V_CE = 5 V, I_C = 200 μA, f = 1 kHz - Noise performance suitable for preamplifier stages but not ultra-low-noise audio.

Pinout & Package

BC548BTAR uses the standard TO-92 3-lead plastic package with straight lead configuration (JEDEC TO-92 compliant), intended for through-hole mounting. Lead spacing is 0.2 inch (5.08 mm); body diameter is 3.2 mm; total length is 4.5 mm.

Pin/Terminal	Circuit Role	Design Meaning
1 (Collector)	Main current output terminal	Connected to load or supply rail in common-emitter topology; carries full collector current and must handle V_CEO stress.
2 (Base)	Control input terminal	Receives forward-biased current to modulate collector current; requires series resistor to limit I_B per h_FE and V_BE(on).
3 (Emitter)	Current return path	Typically grounded or connected to emitter resistor for bias stabilization; reference node for V_BE and V_CE measurements.

Key Features

Feature	Design Value
General-purpose NPN transistor	Validated for both linear amplification (e.g., microphone preamp) and saturated switching (e.g., LED driver) without external compensation.
TO-92 package compatibility	Matches footprint and soldering profile of BC546–BC550 family, enabling drop-in replacement in existing through-hole designs.
Class B h_FE binning	Guarantees 200–450 DC current gain at standardized test conditions, simplifying base resistor selection for consistent turn-on behavior.
Low V_BE(on)	580–700 mV at I_C = 2 mA enables reliable turn-on with 3.3 V or 5 V logic-level drive without level-shifting.
Specified noise figure	2.0–10.0 dB at 1 kHz allows use in non-critical analog signal chains where ultra-low-noise transistors are unnecessary.

Applications

Audio Pre-amplifier Stage	Microcontroller GPIO Interface
Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors before ADC sampling. IC Role / Device Role / Timing Role: Small-signal NPN amplifier in common-emitter configuration with emitter degeneration. Use Value: Predictable h_FE and low V_BE(on) enable stable DC biasing and gain control using standard passive components.	Use Scenario: Driving LEDs, relays, or MOSFET gates from 3.3 V or 5 V microcontroller outputs. IC Role / Device Role / Timing Role: Saturated switch with base current limiting resistor. Use Value: Low V_CE(sat) (≤250 mV) minimizes power loss and heat generation during continuous on-state operation.
Low-Voltage Power Supply Enable	Signal Level Translation
Use Scenario: Enabling/disabling auxiliary rails (e.g., 3.3 V LDO) via microcontroller-controlled pull-down. IC Role / Device Role / Timing Role: High-side or low-side enable switch controlling EN pin of regulator ICs. Use Value: 30 V V_CEO headroom accommodates input rails up to 24 V while maintaining safe margin for transient spikes.	Use Scenario: Converting 1.8 V logic levels to 3.3 V or 5 V compatible signals in mixed-voltage systems. IC Role / Device Role / Timing Role: Active-level translator using common-emitter inverter configuration. Use Value: Fast f_T (300 MHz) supports clean edge transitions up to ~10 MHz without significant rise/fall time degradation.

Audio Pre-amplifier Stage

Microcontroller GPIO Interface

Use Scenario: Amplifying weak signals from electret microphones or piezoelectric sensors before ADC sampling.

IC Role / Device Role / Timing Role: Small-signal NPN amplifier in common-emitter configuration with emitter degeneration.

Use Value: Predictable h_FE and low V_BE(on) enable stable DC biasing and gain control using standard passive components.

Use Scenario: Driving LEDs, relays, or MOSFET gates from 3.3 V or 5 V microcontroller outputs.

IC Role / Device Role / Timing Role: Saturated switch with base current limiting resistor.

Use Value: Low V_CE(sat) (≤250 mV) minimizes power loss and heat generation during continuous on-state operation.

Low-Voltage Power Supply Enable

Signal Level Translation

Use Scenario: Enabling/disabling auxiliary rails (e.g., 3.3 V LDO) via microcontroller-controlled pull-down.

IC Role / Device Role / Timing Role: High-side or low-side enable switch controlling EN pin of regulator ICs.

Use Value: 30 V V_CEO headroom accommodates input rails up to 24 V while maintaining safe margin for transient spikes.

Use Scenario: Converting 1.8 V logic levels to 3.3 V or 5 V compatible signals in mixed-voltage systems.

IC Role / Device Role / Timing Role: Active-level translator using common-emitter inverter configuration.

Use Value: Fast f_T (300 MHz) supports clean edge transitions up to ~10 MHz without significant rise/fall time degradation.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC547BTA	V_CEO = 45 V (vs. 30 V), same h_FE Class B, identical TO-92 package and pinout.	Preferred where higher collector-emitter standoff is required, e.g., 24 V industrial I/O lines.	Select BC547BTA if design requires >30 V V_CEO margin without changing layout or drive network.
PN2222A	V_CEO = 40 V, I_C = 800 mA, P_C = 625 mW, h_FE = 100–300 (unbinned), TO-92 package.	Higher current/power handling but wider h_FE spread; less predictable gain in precision biasing.	Choose PN2222A only when BC548BTAR's 100 mA rating is insufficient and tighter h_FE tolerance is not critical.

Compared with BC547BTA and PN2222A, the BC548BTAR offers optimal balance of gain consistency (Class B), low-noise suitability, and compact 30 V rating for cost-sensitive 5 V/3.3 V embedded signal conditioning-without over-spec'ing voltage or current capability.

Availability

BC548BTAR is available at Aetrix Electronics and suitable for audio pre-amplifier stages, microcontroller GPIO interfaces, low-voltage power supply enable circuits, and signal level translation requiring stable component supply and long-term obsolescence management.

Supply support for BC548BTAR 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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The BC548BTAR belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild and maintained for backward-compatible through-hole designs requiring proven reliability and wide temperature operation.

FAQ

What is the maximum collector-emitter voltage rating for BC548BTAR?

The BC548BTAR has a maximum collector-emitter voltage (V_CEO) rating of 30 V at T_A = 25°C. This value is absolute maximum and must be derated at elevated ambient temperatures. Exceeding this rating risks avalanche breakdown and permanent device failure. The BC548BTAR is not rated for 45 V or higher like the BC547BTA variant.

Is BC548BTAR pin-compatible with other BC54x series transistors?

Yes, BC548BTAR uses the standard TO-92 package with Collector-Base-Emitter pinout (1-2-3), matching all BC546/BC547/BC548/BC549/BC550 variants. Mechanical and electrical pin compatibility is confirmed per JEDEC TO-92 specification and Fairchild/ON Semiconductor documentation. No PCB layout change is needed for substitution within this family.

What h_FE range does BC548BTAR guarantee?

The BC548BTAR is classified as Class B, guaranteeing a DC current gain (h_FE) between 200 and 450 when measured at V_CE = 5 V and I_C = 2 mA. This binning ensures predictable base drive requirements across production lots, unlike unbinned alternatives such as PN2222A.

Can BC548BTAR be used in low-noise audio applications?

The BC548BTAR has a noise figure of 2.0–10.0 dB at 1 kHz, making it suitable for non-critical audio pre-amplifier stages but not for ultra-low-noise microphone front-ends. For lower noise, BC549BTA or BC550CTA (1.2–4.0 dB) are specified alternatives-BC548BTAR itself is not optimized for minimum noise performance.

What is the saturation voltage of BC548BTAR under typical switching conditions?

At I_C = 10 mA and I_B = 0.5 mA, the BC548BTAR exhibits V_CE(sat) between 90 mV and 250 mV. At higher drive (I_C = 100 mA, I_B = 5 mA), V_CE(sat) rises to 250–600 mV. These values define conduction losses in switching applications and inform thermal design margins.

BC548BTAR Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Tape & Box (TB)

Product Status:: Obsolete

Transistor Type:: NPN

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

Voltage - Collector Emitter Breakdown (Max):: 30 V

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

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

DC Current Gain (hFE) (Min) @ Ic, Vce:: 200 @ 2mA, 5V

Power - Max:: 500 mW

Frequency - Transition:: 300MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

BC548BTAR FAQ

1.How can I place an order for BC548BTAR through Aetrix?

Please submit a Request for Quotation (RFQ) for BC548BTAR 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 BC548BTAR reliable?

The price and inventory of BC548BTAR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC548BTAR is usually 5 days.

3.What payment methods are accepted for BC548BTAR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC548BTAR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC548BTAR?

BC548BTAR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC548BTAR 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 BC548BTAR?

For technical support, including BC548BTAR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC548BTAR requirements.

6.How does Aetrix verify that BC548BTAR is sourced from the original manufacturer or authorized distributors?

All BC548BTAR 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 BC548BTAR meets industry standards.

7.What is the process for return or replacement of BC548BTAR?

All BC548BTAR units undergo pre-shipment inspection (PSI). If there is an issue with BC548BTAR, 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 BC548BTAR part is unused and in its original packaging.

Return procedure for BC548BTAR:

1.Submit a request within 90 days.

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

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