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

onsemi BC337-040

Name: BC337-040
Brand: onsemi
SKU: BC337-040
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC337-040

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 Long Body

Datasheet:: BC337-040.pdf

Description:: TRANS NPN 45V 0.8A TO92

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC337-040 from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for 45 V_CEO, 800 mA continuous collector current, and 625 mW dissipation at 25°C ambient. It delivers DC current gain (h_FE) of 250–630 at I_C = 100 mA and V_CE = 1.0 V, with f_T = 210 MHz, suited for low-voltage switching and linear amplification in consumer power supplies and signal conditioning stages.

For engineers reviewing the BC337-040 datasheet, pinout, applications, or equivalent options, key selection criteria include verified h_FE binning (40 variant), V_CE(sat) ≤ 0.7 V at I_C/I_B = 10, thermal resistance R_JA = 200°C/W, and TO-92 mechanical compatibility with legacy through-hole PCB layouts.

Technical Context

The BC337-040 operates as a medium-power NPN bipolar junction transistor optimized for linear amplification and saturated switching. Its h_FE range (250–630) reflects tight gain binning within the BC337 family, enabling predictable biasing without individual device trimming. The device supports V_CEO = 45 V and V_CBO = 50 V, making it suitable for 24 V rail applications with margin.

Thermal design relies on R_JC = 83.3°C/W and R_JA = 200°C/W, with safe operating area (SOA) limited by second breakdown above 1 ms pulses. Small-signal performance includes C_ob = 15 pF and f_T = 210 MHz, confirming utility in audio-frequency and low-MHz switching circuits.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum collector-emitter voltage before breakdown; enables use in 24 V systems with 88% headroom
I_C (continuous)	800 mA - Sustained collector current capability; supports relay drivers and LED arrays up to ~7 W at V_CE ≈ 9 V
h_FE @ 100 mA	250–630 - Tight-gain binning ensures consistent base drive requirements across production lots
V_CE(sat)	≤ 0.7 V @ I_C = 500 mA, I_B = 50 mA - Low saturation voltage reduces conduction loss in switching applications
f_T	210 MHz - Confirmed small-signal bandwidth supports audio preamps and <10 MHz digital signal buffering
R_JA	200°C/W - Thermal resistance defines maximum power derating: 5 mW/°C above 25°C ambient

Pinout & Package

BC337-040 uses the standard TO-92 (Case 29, Style 17) through-hole package with 3.18–4.19 mm body width, 4.45–5.20 mm height, and 2.54 mm lead pitch. Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter, as marked on the device body with "7−40".

Pin/Terminal	Circuit Role	Design Meaning
1 (Collector)	Main current output terminal	Connected to load or supply rail; handles full I_C up to 800 mA; requires thermal relief on PCB for >300 mA operation
2 (Base)	Control input for minority-carrier injection	Drives with 10–50 mA to achieve saturation; requires series resistor to limit I_B and prevent thermal runaway
3 (Emitter)	Current return path and reference node	Typically grounded or tied to emitter resistor for bias stabilization; carries same current as collector plus base current

Key Features

Feature	Design Value
Gain-binned h_FE	250–630 at I_C = 100 mA - Enables predictable DC bias networks without post-layout trimming
Low V_CE(sat)	≤ 0.7 V under forced β = 10 - Reduces power loss and self-heating in high-duty-cycle switching
High f_T	210 MHz - Supports stable amplification up to mid-audio frequencies with minimal phase shift
Pb-free option	BC337-40G available - Complies with RoHS Directive 2011/65/EU without compromising electrical specs

Applications

Audio Pre-amplifier Stage	DC Motor Speed Control
Use Scenario: Amplifying microphone-level signals (1–10 mV) to line-level (0.3–1 V) in portable audio recorders. IC Role / Device Role / Timing Role: Linear NPN amplifier configured in common-emitter topology with emitter degeneration. Use Value: h_FE ≥ 250 ensures ≥ 20 dB voltage gain with minimal distortion; f_T = 210 MHz avoids roll-off below 20 kHz.	Use Scenario: PWM-driven 12 V brushed DC motor (100–500 mA load) in robotic actuators. IC Role / Device Role / Timing Role: Saturated switch controlling motor current path between supply and ground. Use Value: V_CE(sat) ≤ 0.7 V limits conduction loss to <350 mW at 500 mA, reducing thermal stress on TO-92 package.
LED Constant-Current Driver	Power Supply Error Amplifier
Use Scenario: Driving 3× white LEDs (9 V total V_F) from 12 V supply in indicator panels. IC Role / Device Role / Timing Role: Current-regulating pass element with feedback resistor network. Use Value: I_C = 800 mA rating accommodates peak LED surge currents; V_CEO = 45 V provides margin against supply transients.	Use Scenario: Error amplification stage in 5 V/3 A buck converter feedback loop. IC Role / Device Role / Timing Role: Transconductance amplifier comparing output voltage to reference and driving PWM comparator input. Use Value: f_T = 210 MHz supports loop bandwidths up to 1 MHz; low C_ob = 15 pF minimizes phase lag in compensation network.

Audio Pre-amplifier Stage

DC Motor Speed Control

Use Scenario: Amplifying microphone-level signals (1–10 mV) to line-level (0.3–1 V) in portable audio recorders.

IC Role / Device Role / Timing Role: Linear NPN amplifier configured in common-emitter topology with emitter degeneration.

Use Value: h_FE ≥ 250 ensures ≥ 20 dB voltage gain with minimal distortion; f_T = 210 MHz avoids roll-off below 20 kHz.

Use Scenario: PWM-driven 12 V brushed DC motor (100–500 mA load) in robotic actuators.

IC Role / Device Role / Timing Role: Saturated switch controlling motor current path between supply and ground.

Use Value: V_CE(sat) ≤ 0.7 V limits conduction loss to <350 mW at 500 mA, reducing thermal stress on TO-92 package.

LED Constant-Current Driver

Power Supply Error Amplifier

Use Scenario: Driving 3× white LEDs (9 V total V_F) from 12 V supply in indicator panels.

IC Role / Device Role / Timing Role: Current-regulating pass element with feedback resistor network.

Use Value: I_C = 800 mA rating accommodates peak LED surge currents; V_CEO = 45 V provides margin against supply transients.

Use Scenario: Error amplification stage in 5 V/3 A buck converter feedback loop.

IC Role / Device Role / Timing Role: Transconductance amplifier comparing output voltage to reference and driving PWM comparator input.

Use Value: f_T = 210 MHz supports loop bandwidths up to 1 MHz; low C_ob = 15 pF minimizes phase lag in compensation network.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC337-25	h_FE = 160–400 (lower min/max); otherwise identical ratings and pinout	Suitable where lower gain consistency is acceptable, e.g., non-critical switching	Select BC337-25 when tighter h_FE tolerance is unnecessary and cost optimization is prioritized
BC817-40	SOT-23 surface-mount package; same h_FE bin (250–630); V_CEO = 45 V, I_C = 500 mA (lower than BC337-040)	Used in space-constrained PCBs where TO-92 footprint is unavailable	Choose BC817-40 only if board layout mandates SMT and 500 mA I_C suffices

Compared with BC337-25 and BC817-40, the BC337-040 offers the highest guaranteed h_FE floor (250) and highest continuous I_C (800 mA) in the TO-92 form factor, making it optimal for designs requiring robust gain stability and higher current drive without SMT conversion.

Availability

BC337-040 is available at Aetrix Electronics and suitable for audio pre-amplifiers, DC motor controllers, LED drivers, and power supply error amplifiers requiring stable component supply across industrial and consumer production cycles.

Supply support for BC337-040 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power and sensing solutions, with leadership in automotive, industrial, and cloud infrastructure markets.

The BC337-040 belongs to onsemi's legacy general-purpose transistor product line, designed for cost-sensitive, high-volume applications demanding reliable gain consistency, thermal robustness, and long-term manufacturability in through-hole assembly.

FAQ

What is the guaranteed minimum h_FE for BC337-040 at I_C = 100 mA?

The BC337-040 guarantees h_FE ≥ 250 at I_C = 100 mA and V_CE = 1.0 V, per the official onsemi datasheet revision 5. This minimum value distinguishes it from lower-binned variants like BC337-25 (min h_FE = 160) and ensures predictable base current requirements in production designs using the BC337-040.

Is BC337-040 compatible with standard TO-92 footprints?

Yes, BC337-040 uses the industry-standard TO-92 package (Case 29, Style 17) with 2.54 mm lead pitch and defined pinout: Pin 1 = Collector, Pin 2 = Base, Pin 3 = Emitter. Its mechanical dimensions match JEDEC TO-92 specifications, ensuring drop-in compatibility with existing PCB layouts designed for BC337-series transistors.

Does BC337-040 support Pb-free soldering processes?

Yes - the BC337-040G variant is explicitly qualified for Pb-free reflow soldering per J-STD-020, with the same electrical and thermal specifications as the standard BC337-040. The "G" suffix denotes RoHS-compliant packaging, and both versions share identical marking ("7−40") and TO-92 mechanical form.

What is the maximum power dissipation for BC337-040 at 70°C ambient?

At T_A = 70°C, BC337-040's maximum power dissipation is 412.5 mW. This is calculated from its 625 mW rating at 25°C and 5.0 mW/°C derating: 625 mW − (70 − 25) × 5.0 = 412.5 mW. Exceeding this risks junction temperature exceeding 150°C, triggering thermal shutdown or permanent degradation of the BC337-040.

Can BC337-040 be used in linear regulator pass transistor applications?

BC337-040 can serve as a low-power pass transistor in adjustable linear regulators delivering ≤300 mA, provided V_IN − V_OUT ≤ 10 V and heatsinking is applied. Its V_CEO = 45 V and I_C = 800 mA allow margin, but R_JA = 200°C/W limits continuous dissipation to ~300 mW at 70°C ambient - sufficient for dropout voltages under 1 V at 300 mA, as required in many BC337-040-based regulator designs.

BC337-040 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body

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:: 250 @ 100mA, 1V

Power - Max:: 625 mW

Frequency - Transition:: 210MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92 (TO-226)

BC337-040 FAQ

1.How can I place an order for BC337-040 through Aetrix?

Please submit a Request for Quotation (RFQ) for BC337-040 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 BC337-040 reliable?

The price and inventory of BC337-040 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC337-040 is usually 5 days.

3.What payment methods are accepted for BC337-040?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC337-040 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC337-040?

BC337-040 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC337-040 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 BC337-040?

For technical support, including BC337-040 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC337-040 requirements.

6.How does Aetrix verify that BC337-040 is sourced from the original manufacturer or authorized distributors?

All BC337-040 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 BC337-040 meets industry standards.

7.What is the process for return or replacement of BC337-040?

All BC337-040 units undergo pre-shipment inspection (PSI). If there is an issue with BC337-040, 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 BC337-040 part is unused and in its original packaging.

Return procedure for BC337-040:

1.Submit a request within 90 days.

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

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