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

onsemi BD241C

Name: BD241C
Brand: onsemi
SKU: BD241C
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BD241C

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: BD241C.pdf

Description:: TRANS NPN 100V 3A TO-220

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BD241C from ON Semiconductor is a medium-power NPN epitaxial silicon transistor rated for 100 V V_CEO, 3 A continuous collector current, and 40 W collector dissipation at T_C = 25°C, used in linear amplification and switching applications such as power supply regulators and motor drivers.

For engineers reviewing the BD241C datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO = 100 V, h_FE ≥ 10 at I_C = 3 A, V_CE(sat) ≤ 1.2 V, TO-220 package thermal performance, and complementary pairing with BD242C.

Technical Context

The BD241C operates as a general-purpose bipolar junction transistor with fixed-emitter configuration and base-controlled current amplification. Its design supports both linear-mode operation (e.g., Class-A/B amplifiers) and saturated-switching mode (e.g., relay or solenoid drivers), validated by specified V_CE(sat) = 1.2 V at I_C = 3 A and I_B = 0.6 A.

It features a maximum junction temperature of 150°C and storage range of –65°C to +150°C, enabling use in industrial ambient environments. The device is not rated for automotive AEC-Q101 stress testing and lacks integrated protection features such as built-in diodes or thermal shutdown.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	100 V - Maximum DC collector-emitter voltage before breakdown; defines safe operating voltage ceiling in switching circuits.
I_C (DC)	3 A - Continuous collector current rating; determines maximum load-handling capability in steady-state operation.
P_C	40 W - Collector power dissipation at T_C = 25°C; sets heatsink sizing requirement under full-load conduction.
h_FE	≥10 at I_C = 3 A - Minimum DC current gain; ensures reliable base drive margin for saturation in switching designs.
V_CE(sat)	≤1.2 V at I_C = 3 A, I_B = 0.6 A - Saturation voltage drop; directly impacts conduction loss and thermal rise in on-state operation.
T_J	150°C - Maximum allowable junction temperature; constrains thermal design and derating curves above 25°C case temperature.

Pinout & Package

BD241C uses the standard TO-220 package with 3 leads: Base (pin 1), Collector (pin 2), Emitter (pin 3). The metal tab is electrically connected to the collector and must be isolated from chassis ground unless intentionally tied to collector potential.

Pin/Terminal	Circuit Role	Design Meaning
1 (Base)	Current-controlled input terminal	Receives base drive current to modulate collector current; requires external current-limiting resistor in most configurations.
2 (Collector)	Main high-side current path terminal	Connected to load or supply rail; metal tab is electrically common with this pin and must be insulated if not referenced to same potential.
3 (Emitter)	Common return path for collector and base currents	Serves as reference node for bias network and load return; often grounded or tied to negative rail in low-side switch topologies.

Key Features

Feature	Design Value
High V_CEO rating	100 V enables use in 48 V industrial bus systems and offline auxiliary supplies without series stacking.
Medium-power dissipation	40 W at T_C = 25°C supports compact heatsinking in space-constrained control modules.
Complementary pairing	Designed as NPN counterpart to BD242C PNP, enabling push-pull output stages and H-bridge driver sections.
Epitaxial silicon construction	Provides stable h_FE and low leakage (I_CEO ≤ 0.3 mA) across temperature and production lots.

Applications

Power Supply Regulation	Motor Control Interface
Use Scenario: Linear pass transistor in adjustable 0–30 V, 3 A bench power supply. IC Role / Device Role / Timing Role: NPN series pass element controlled by op-amp feedback loop. Use Value: V_CEO = 100 V allows 40 V input headroom; V_CE(sat) ≤ 1.2 V minimizes dropout and heat generation at full load.	Use Scenario: Low-frequency PWM-driven DC motor driver in industrial actuator. IC Role / Device Role / Timing Role: Single-ended NPN switch controlling motor winding current. Use Value: I_C = 3 A and P_C = 40 W support 24 V/2 A motor loads with passive heatsinking; TO-220 mechanical robustness withstands vibration.
Audio Amplifier Output Stage	Relay/Solenoid Driver
Use Scenario: Class-B emitter-follower output stage in 10 W audio amplifier. IC Role / Device Role / Timing Role: Current-buffering NPN transistor delivering speaker current. Use Value: h_FE ≥ 10 at I_C = 3 A ensures sufficient drive capability into 4 Ω loads; low V_BE(on) = 1.8 V simplifies bias network design.	Use Scenario: High-current coil driver for 24 V industrial relay (1.2 A coil). IC Role / Device Role / Timing Role: Saturated-switch NPN transistor replacing mechanical contactor. Use Value: V_CE(sat) ≤ 1.2 V limits coil power loss to <1.5 W; TO-220 mounting enables direct PCB heatsinking on metal chassis.

Power Supply Regulation

Motor Control Interface

Use Scenario: Linear pass transistor in adjustable 0–30 V, 3 A bench power supply.

IC Role / Device Role / Timing Role: NPN series pass element controlled by op-amp feedback loop.

Use Value: V_CEO = 100 V allows 40 V input headroom; V_CE(sat) ≤ 1.2 V minimizes dropout and heat generation at full load.

Use Scenario: Low-frequency PWM-driven DC motor driver in industrial actuator.

IC Role / Device Role / Timing Role: Single-ended NPN switch controlling motor winding current.

Use Value: I_C = 3 A and P_C = 40 W support 24 V/2 A motor loads with passive heatsinking; TO-220 mechanical robustness withstands vibration.

Audio Amplifier Output Stage

Relay/Solenoid Driver

Use Scenario: Class-B emitter-follower output stage in 10 W audio amplifier.

IC Role / Device Role / Timing Role: Current-buffering NPN transistor delivering speaker current.

Use Value: h_FE ≥ 10 at I_C = 3 A ensures sufficient drive capability into 4 Ω loads; low V_BE(on) = 1.8 V simplifies bias network design.

Use Scenario: High-current coil driver for 24 V industrial relay (1.2 A coil).

IC Role / Device Role / Timing Role: Saturated-switch NPN transistor replacing mechanical contactor.

Use Value: V_CE(sat) ≤ 1.2 V limits coil power loss to <1.5 W; TO-220 mounting enables direct PCB heatsinking on metal chassis.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD243G	TO-263 package, higher h_FE (min 30 at I_C = 3 A), same V_CEO = 100 V, lower P_C = 35 W	Surface-mount alternative requiring re-layout; better gain linearity but reduced thermal margin	Select when board space is constrained and thermal management uses copper pour instead of heatsink.
TIP31C	Same TO-220 package, lower V_CEO = 100 V (same), identical I_C = 3 A, but h_FE min = 10 only at I_C = 1 A (not 3 A)	Less predictable gain at full load; requires larger base drive for saturation at 3 A	Select only if base drive circuit can deliver ≥1 A peak and thermal margin exceeds 20%.

Compared with MJD243G and TIP31C, BD241C offers verified h_FE ≥10 at full 3 A load and proven TO-220 thermal reliability in legacy industrial designs-making it preferred where gain consistency and mechanical serviceability matter more than footprint reduction.

Availability

BD241C is available at Aetrix Electronics and suitable for power supply regulation, motor control interface, audio amplifier output stages, and relay/solenoid driver applications requiring stable component supply and long-term industrial availability.

Supply support for BD241C 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 supplier specializing in energy-efficient power management, analog, sensors, and connectivity solutions for automotive, industrial, cloud computing, and consumer markets.

BD241C belongs to ON Semiconductor's legacy discrete transistor product line, originally developed by Fairchild Semiconductor for general-purpose medium-power linear and switching applications in industrial controls and power electronics.

FAQ

What is the maximum collector-emitter voltage rating for BD241C?

The BD241C has a maximum collector-emitter voltage (V_CEO) rating of 100 V at T_C = 25°C. This value is confirmed in the Absolute Maximum Ratings table and applies under DC conditions with base open. Exceeding this voltage risks avalanche breakdown and permanent device failure. Derating is required above 25°C case temperature per the published thermal curve.

Does BD241C have a built-in base-emitter resistor or protection diode?

No, BD241C is a standard three-terminal NPN bipolar transistor with no integrated resistors or protection diodes. It requires external base current limiting and, in inductive load applications, an external flyback diode across the collector-emitter terminals. This discrete architecture provides design flexibility but places full responsibility for drive and protection on the circuit designer.

What is the guaranteed minimum DC current gain (h_FE) of BD241C at full load?

The BD241C guarantees h_FE ≥ 10 at V_CE = 4 V and I_C = 3 A, as specified in the Electrical Characteristics table. This minimum gain is tested and binned during production. At lower collector currents (e.g., I_C = 1 A), h_FE increases to ≥25, but system-level saturation design must be based on the 3 A condition to ensure robust turn-on.

Can BD241C be used as a direct replacement for BD241A or BD241B?

No, BD241C is not a drop-in replacement for BD241A or BD241B due to differing absolute maximum ratings: BD241C supports V_CEO = 100 V versus 60 V (A) and 80 V (B). Substituting BD241C into a design originally using BD241A may introduce unnecessary cost and thermal overhead, while substituting a lower-voltage variant risks catastrophic failure in 100 V circuits. Always verify voltage stress margins before interchange.

What is the thermal resistance from junction to case (R_θJC) for BD241C?

The BD241C has a typical junction-to-case thermal resistance (R_θJC) of 0.625°C/W, derived from its 40 W power dissipation rating and 25°C case temperature reference (R_θJC = (T_J − T_C) / P_C = (150 − 25) / 40). This value assumes full metal tab contact with a heatsink and is critical for calculating required heatsink thermal resistance in real-world applications.

BD241C Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 3 A

Voltage - Collector Emitter Breakdown (Max):: 100 V

Vce Saturation (Max) @ Ib, Ic:: 1.2V @ 600mA, 3A

Current - Collector Cutoff (Max):: 300µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 25 @ 1A, 4V

Power - Max:: 40 W

Frequency - Transition:: 3MHz

Operating Temperature:: -65°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

BD241C FAQ

1.How can I place an order for BD241C through Aetrix?

Please submit a Request for Quotation (RFQ) for BD241C 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 BD241C reliable?

The price and inventory of BD241C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BD241C is usually 5 days.

3.What payment methods are accepted for BD241C?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BD241C transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BD241C?

BD241C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BD241C 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 BD241C?

For technical support, including BD241C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BD241C requirements.

6.How does Aetrix verify that BD241C is sourced from the original manufacturer or authorized distributors?

All BD241C 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 BD241C meets industry standards.

7.What is the process for return or replacement of BD241C?

All BD241C units undergo pre-shipment inspection (PSI). If there is an issue with BD241C, 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 BD241C part is unused and in its original packaging.

Return procedure for BD241C:

1.Submit a request within 90 days.

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

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