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

onsemi BC337ABU

Name: BC337ABU
Brand: onsemi
SKU: BC337ABU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC337ABU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: BC337ABU.pdf

Description:: TRANS NPN 45V 0.8A TO-92-3

Quantity:: RFQ Add To RFQ list

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Inventory:4,772

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Product details

Overview

BC337ABU from Fairchild Semiconductor is an NPN epitaxial silicon transistor designed for low-power switching and amplification in general-purpose analog and digital circuits, with V_CEO = 45 V, I_C = 800 mA, P_C = 625 mW, h_FE = 100–250 (Class A), and TO-92 package - commonly used in AF driver stages and low-power output stages.

For engineers reviewing the BC337ABU datasheet, pinout, applications, or equivalent options, key selection criteria include DC current gain classification, saturation voltage at 500 mA, breakdown voltage margin, thermal derating behavior, and complementary pairing with BC327/BC328 in push-pull configurations.

Technical Context

The BC337ABU operates as a general-purpose bipolar junction transistor with fixed-emitter biasing capability and linear amplification up to f_T = 100 MHz under V_CE = 5 V, I_C = 10 mA conditions. Its h_FE classification (A = 100–250) ensures predictable current amplification in Class-A amplifier biasing and saturated-switch operation.

Designed for discrete circuit implementation, it features low V_CE(sat) = 0.7 V at I_C = 500 mA / I_B = 50 mA and V_BE(on) = 1.2 V at I_C = 300 mA, enabling efficient drive of small relays, LEDs, and logic-level interface loads without external base resistors in many cases.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum safe collector-emitter voltage before avalanche breakdown in common-emitter configuration
I_C (DC)	800 mA - Continuous collector current rating defining maximum load-driving capacity
P_C	625 mW - Thermal power dissipation limit at T_A = 25°C, requiring heatsinking above ~250 mW in enclosed environments
h_FE (Class A)	100–250 - Guaranteed DC current gain range at V_CE = 1 V, I_C = 100 mA, critical for stable bias point design
V_CE(sat)	0.7 V - Collector-emitter voltage drop in hard saturation, directly impacting switch efficiency and power loss
f_T	100 MHz - Transition frequency indicating usable bandwidth for small-signal amplification up to mid-VHF range

Pinout & Package

BC337ABU is housed in a standard TO-92 plastic package with 3 leads: Collector (lead 1), Base (lead 2), Emitter (lead 3), conforming to JEDEC TO-92 outline dimensions (max height 4.58 mm, lead pitch 1.27 mm).

Pin/Terminal	Circuit Role	Design Meaning
1 (Collector)	Main current sink terminal	Connected to load supply rail; must withstand full V_CEO and handle I_C during conduction
2 (Base)	Control input node	Receives forward-biased current to enable transistor conduction; requires series resistor for current limiting
3 (Emitter)	Current return path	Typically grounded or tied to reference potential; defines emitter-follower or common-emitter topology

Key Features

Feature	Design Value
Complementary pair compatibility	Directly paired with BC327 PNP for push-pull output stages and differential amplifiers
Low saturation voltage	V_CE(sat) ≤ 0.7 V at I_C/I_B = 10, enabling high-efficiency switching in battery-powered systems
High f_T bandwidth	100 MHz transition frequency supports audio-frequency amplification and fast digital switching up to ~10 MHz
Robust thermal rating	Junction temperature limit of 150°C allows operation in industrial ambient environments up to 85°C with proper PCB copper area

Applications

Audio Frequency Driver	Low-Power Relay Interface
Use Scenario: Driving 8 Ω speaker loads in portable audio preamplifier output stages. IC Role / Device Role / Timing Role: NPN amplifier in common-emitter configuration providing voltage and current gain. Use Value: h_FE ≥ 100 ensures stable biasing; V_CE(sat) ≤ 0.7 V minimizes distortion and heat generation at 100–300 mA peak currents.	Use Scenario: Controlling 12 V, 200 mA coil relays from microcontroller GPIO pins. IC Role / Device Role / Timing Role: Low-side switch with base driven by 3.3 V or 5 V logic. Use Value: I_C = 800 mA headroom prevents thermal runaway; V_BE(on) = 1.2 V ensures reliable turn-on with standard TTL/CMOS logic levels.
Digital Logic Level Shifter	Complementary Push-Pull Output
Use Scenario: Translating 3.3 V MCU outputs to 5 V or 12 V peripheral control signals. IC Role / Device Role / Timing Role: Saturated switch operating in cutoff/saturation regions only. Use Value: Fast turn-on/off due to f_T = 100 MHz and low Cob = 12 pF enables clean edge transitions up to 5 MHz clock rates.	Use Scenario: Output stage of linear voltage regulators or class-B audio amplifiers. IC Role / Device Role / Timing Role: NPN half of complementary BC337/BC327 pair delivering positive half-cycle current. Use Value: Matched h_FE classification and V_CE(sat) ensure symmetrical conduction and reduced crossover distortion.

Audio Frequency Driver

Low-Power Relay Interface

Use Scenario: Driving 8 Ω speaker loads in portable audio preamplifier output stages.

IC Role / Device Role / Timing Role: NPN amplifier in common-emitter configuration providing voltage and current gain.

Use Value: h_FE ≥ 100 ensures stable biasing; V_CE(sat) ≤ 0.7 V minimizes distortion and heat generation at 100–300 mA peak currents.

Use Scenario: Controlling 12 V, 200 mA coil relays from microcontroller GPIO pins.

IC Role / Device Role / Timing Role: Low-side switch with base driven by 3.3 V or 5 V logic.

Use Value: I_C = 800 mA headroom prevents thermal runaway; V_BE(on) = 1.2 V ensures reliable turn-on with standard TTL/CMOS logic levels.

Digital Logic Level Shifter

Complementary Push-Pull Output

Use Scenario: Translating 3.3 V MCU outputs to 5 V or 12 V peripheral control signals.

IC Role / Device Role / Timing Role: Saturated switch operating in cutoff/saturation regions only.

Use Value: Fast turn-on/off due to f_T = 100 MHz and low Cob = 12 pF enables clean edge transitions up to 5 MHz clock rates.

Use Scenario: Output stage of linear voltage regulators or class-B audio amplifiers.

IC Role / Device Role / Timing Role: NPN half of complementary BC337/BC327 pair delivering positive half-cycle current.

Use Value: Matched h_FE classification and V_CE(sat) ensure symmetrical conduction and reduced crossover distortion.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC337-25	Same TO-92 package; h_FE = 160–400 (Class B), higher gain variation than BC337ABU's 100–250 range	Better suited for high-gain amplifier designs where precise bias stability is less critical	Select BC337-25 when higher h_FE improves loop gain in feedback amplifiers without requiring tighter tolerance
PN2222A	V_CEO = 40 V (vs. 45 V), I_C = 800 mA, h_FE = 100–300, TO-92 - slightly lower breakdown margin and broader h_FE spread	Widely available legacy alternative with identical pinout but less consistent gain grouping	Choose PN2222A only if BC337ABU is unavailable and system tolerates ±20% h_FE variation across production lots

Compared with BC337-25 and PN2222A, the BC337ABU offers tighter h_FE binning (100–250) and highest V_CEO, making it preferable for safety-critical switching and precision-biased amplifiers where gain predictability and voltage margin are prioritized over raw gain.

Availability

BC337ABU is available at Aetrix Electronics and suitable for audio driver stages, relay interface circuits, level-shifting networks, and complementary output topologies requiring stable component supply and long-term manufacturability.

Supply support for BC337ABU 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 and manufacturer of analog and discrete semiconductors, acquired by ON Semiconductor in 2016; its legacy BC337 series remains widely supported and qualified.

The BC337ABU belongs to Fairchild's general-purpose bipolar transistor family, engineered for cost-sensitive, high-reliability linear and switching applications in consumer, industrial, and automotive auxiliary systems.

FAQ

What is the hFE classification of BC337ABU?

The BC337ABU is classified as "Class A", meaning its DC current gain (h_FE) is guaranteed between 100 and 250 when measured at V_CE = 1 V and I_C = 100 mA. This tight binning supports repeatable bias point design in amplifier and switching circuits. The BC337ABU datasheet explicitly lists this range under the h_FE1 parameter column for BC337 devices.

Is BC337ABU pin-compatible with BC337-16 or BC337-40?

Yes - BC337ABU shares identical TO-92 package dimensions and pinout (Collector-Base-Emitter = lead 1-2-3) with all BC337 variants including BC337-16 and BC337-40. However, h_FE ranges differ: BC337-16 is 100–160, BC337ABU is 100–250, and BC337-40 is 250–630. Substitution requires verifying gain requirements per circuit function.

What is the maximum continuous collector current for BC337ABU?

The BC337ABU has a rated DC collector current (I_C) of 800 mA at T_A = 25°C. Derating is required above 25°C ambient: approximately 8 mA/°C reduction beyond 25°C, reaching zero at ~125°C case temperature. This limit applies to steady-state conduction, not pulsed operation.

Does BC337ABU support switching applications at 1 MHz?

The BC337ABU has an f_T of 100 MHz, but practical switching speed is limited by storage time and capacitance. At I_C = 100 mA, typical turn-off delay exceeds 100 ns, making reliable 1 MHz square-wave switching marginal. For >500 kHz switching, consider faster transistors like MMBT3904 or dedicated MOSFETs instead of BC337ABU.

Can BC337ABU be used as a direct replacement for BC337-25 in existing designs?

BC337ABU can replace BC337-25 electrically and mechanically, but h_FE differences matter: BC337ABU (100–250) has lower maximum gain than BC337-25 (160–400). In bias-sensitive amplifier circuits, this may shift Q-point or reduce gain margin. Verify DC operating point and small-signal performance before substitution in BC337ABU-based designs.

BC337ABU Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 800 mA

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 700mV @ 50mA, 500mA

Current - Collector Cutoff (Max):: 100nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 100mA, 1V

Power - Max:: 625 mW

Frequency - Transition:: 100MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

BC337ABU FAQ

1.How can I place an order for BC337ABU through Aetrix?

Please submit a Request for Quotation (RFQ) for BC337ABU 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 BC337ABU reliable?

The price and inventory of BC337ABU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC337ABU is usually 5 days.

3.What payment methods are accepted for BC337ABU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC337ABU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC337ABU?

BC337ABU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC337ABU 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 BC337ABU?

For technical support, including BC337ABU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC337ABU requirements.

6.How does Aetrix verify that BC337ABU is sourced from the original manufacturer or authorized distributors?

All BC337ABU 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 BC337ABU meets industry standards.

7.What is the process for return or replacement of BC337ABU?

All BC337ABU units undergo pre-shipment inspection (PSI). If there is an issue with BC337ABU, 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 BC337ABU part is unused and in its original packaging.

Return procedure for BC337ABU:

1.Submit a request within 90 days.

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

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