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

onsemi BD242C

Name: BD242C
Brand: onsemi
SKU: BD242C
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BD242C

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: BD242C.pdf

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

Quantity:: RFQ Add To RFQ list

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Inventory:8,646

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Product details

Overview

BD242C from ON Semiconductor is an NPN epitaxial silicon power transistor in TO-220 package, rated for 100 V V_CEO, 3 A continuous collector current, and 40 W collector dissipation at T_C = 25°C. It serves as a medium-power linear amplifier and switching device in DC motor drives, power supplies, and relay drivers.

For engineers reviewing the BD242C datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO rating, h_FE consistency at 1–3 A, V_CE(sat) under 1.2 V at I_C = 3 A / I_B = 0.6 A, thermal performance in TO-220, and complementary pairing with BD241C.

Technical Context

The BD242C operates as a bipolar junction transistor with fixed NPN polarity, requiring base current drive to control collector current flow. Its sustaining voltage V_CEO(sus) matches its absolute maximum V_CEO rating of 100 V, confirming robust breakdown margin under open-base conditions.

Designed for linear and switching use, it delivers h_FE ≥ 25 at I_C = 1 A and ≥ 10 at I_C = 3 A (V_CE = 4 V), with V_BE(on) = 1.8 V and V_CE(sat) = 1.2 V under specified drive-enabling predictable biasing and low conduction loss in saturated-switch applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	100 V - Maximum allowable collector-emitter voltage before breakdown; defines safe operating voltage ceiling in switching or linear mode.
I_C (DC)	3 A - Continuous collector current limit; determines max load-handling capability without thermal runaway at T_C = 25°C.
P_C	40 W - Collector power dissipation at case temperature 25°C; sets heatsink requirement baseline for sustained operation.
h_FE	25 (min) @ I_C = 1 A - Minimum DC current gain; enables stable base drive design for low-to-moderate current amplification stages.
V_CE(sat)	1.2 V @ I_C = 3 A, I_B = 0.6 A - Saturation voltage drop; directly impacts conduction loss and junction heating in switch-mode operation.
T_J	150 °C - Maximum junction temperature; constrains thermal design margin and derating curves above 25°C case temperature.

Pinout & Package

BD242C uses the standard TO-220 package with 3 leads: emitter, base, and collector. The package features a metal tab (collector-connected) for mechanical mounting and thermal conduction to heatsinks.

Pin/Terminal	Circuit Role	Design Meaning
1 (Base)	Control input	Receives forward-biased current to enable collector-emitter conduction; requires ~0.6 A drive for full saturation at 3 A load.
2 (Collector)	High-current output	Connected internally to metal tab; must be electrically isolated from heatsink unless circuit design permits common-collector configuration.
3 (Emitter)	Reference terminal	Serves as current return path; typically grounded or connected to load return; establishes reference for base-emitter bias network.

Key Features

Feature	Design Value
Complementary pair with BD241C	Enables push-pull or H-bridge configurations without redesigning drive networks or layout-matching V_CEO, I_C, and thermal specs.
100 V V_CEO rating	Supports operation across 48 V industrial bus systems and 100 V peak rectified AC lines with safety margin.
TO-220 mechanical form factor	Provides standardized mounting, heatsinking, and PCB footprint compatibility with legacy and new designs using industry-wide tooling.
h_FE ≥ 10 @ 3 A	Ensures usable current gain even at full-rated load, reducing required base drive power and simplifying driver stage design.

Applications

DC Motor Control	Linear Power Supply Regulator
Use Scenario: Driving brushed DC motors up to 3 A in industrial actuators or automotive auxiliary systems. IC Role / Device Role / Timing Role: NPN power switch controlling motor current direction and on/off state via base drive signal. Use Value: 100 V V_CEO accommodates back-EMF spikes; 40 W dissipation allows brief overload tolerance during stall conditions.	Use Scenario: Pass transistor in adjustable linear regulators delivering up to 3 A output current. IC Role / Device Role / Timing Role: Series pass element dissipating excess voltage between unregulated input and regulated output. Use Value: V_CE(sat) ≤ 1.2 V minimizes dropout voltage; h_FE stability ensures consistent regulation loop response across load range.
Relay Driver Circuit	Switch-Mode Power Supply (SMPS) Gate Driver Stage
Use Scenario: High-current interface between microcontroller GPIO and 12–24 V electromagnetic relays. IC Role / Device Role / Timing Role: Current amplifier converting logic-level signals into sufficient coil drive current (typically 100–500 mA). Use Value: Low V_BE(on) (1.8 V) ensures reliable turn-on from 3.3 V or 5 V logic; TO-220 thermal mass absorbs transient coil energy.	Use Scenario: Level-shifting and current-boosting stage driving high-side MOSFET gates in half-bridge SMPS topologies. IC Role / Device Role / Timing Role: Bipolar buffer amplifying PWM controller output to deliver fast gate charge/discharge current. Use Value: 3 A I_C rating supports gate drive peaks >1 A; 150 °C T_J withstands localized heating near switching nodes.

DC Motor Control

Linear Power Supply Regulator

Use Scenario: Driving brushed DC motors up to 3 A in industrial actuators or automotive auxiliary systems.

IC Role / Device Role / Timing Role: NPN power switch controlling motor current direction and on/off state via base drive signal.

Use Value: 100 V V_CEO accommodates back-EMF spikes; 40 W dissipation allows brief overload tolerance during stall conditions.

Use Scenario: Pass transistor in adjustable linear regulators delivering up to 3 A output current.

IC Role / Device Role / Timing Role: Series pass element dissipating excess voltage between unregulated input and regulated output.

Use Value: V_CE(sat) ≤ 1.2 V minimizes dropout voltage; h_FE stability ensures consistent regulation loop response across load range.

Relay Driver Circuit

Switch-Mode Power Supply (SMPS) Gate Driver Stage

Use Scenario: High-current interface between microcontroller GPIO and 12–24 V electromagnetic relays.

IC Role / Device Role / Timing Role: Current amplifier converting logic-level signals into sufficient coil drive current (typically 100–500 mA).

Use Value: Low V_BE(on) (1.8 V) ensures reliable turn-on from 3.3 V or 5 V logic; TO-220 thermal mass absorbs transient coil energy.

Use Scenario: Level-shifting and current-boosting stage driving high-side MOSFET gates in half-bridge SMPS topologies.

IC Role / Device Role / Timing Role: Bipolar buffer amplifying PWM controller output to deliver fast gate charge/discharge current.

Use Value: 3 A I_C rating supports gate drive peaks >1 A; 150 °C T_J withstands localized heating near switching nodes.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD242G	Same V_CEO (100 V), lower P_C (30 W), SOT-223 package (surface-mount)	Not suitable for through-hole heatsink mounting; limited thermal mass for pulsed loads	Select when board space is constrained and thermal load is steady-state <2 A.
BD242B	Lower V_CEO (80 V), identical package and pinout, same h_FE/V_CE(sat) specs	Acceptable where system voltage remains ≤60 V DC; reduces cost if 100 V margin is unnecessary	Choose for cost-sensitive 24–48 V systems with verified voltage headroom.

Compared with MJD242G and BD242B, the BD242C offers the highest voltage rating and highest power dissipation in through-hole TO-220 format-making it optimal for ruggedized, field-serviceable, or thermally demanding 100 V-class applications where surface-mount alternatives lack sufficient thermal inertia.

Availability

BD242C is available at Aetrix Electronics and suitable for DC motor control, linear power supply regulation, and relay driver circuits requiring stable component supply and long-term industrial availability.

Supply support for BD242C 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 BD242C belongs to ON Semiconductor's legacy power bipolar transistor product line, designed specifically for medium-power linear amplification and robust switching in industrial control, power conversion, and electromechanical interface applications.

FAQ

What is the maximum collector-emitter voltage rating for BD242C?

The BD242C has a maximum collector-emitter voltage (V_CEO) rating of 100 V at T_C = 25°C. This value is confirmed in both absolute maximum ratings and electrical characteristics tables. Exceeding this voltage risks avalanche breakdown or permanent device failure. Derating is required at elevated case temperatures per the datasheet thermal curves.

Is BD242C pin-compatible with BD242B or BD242A?

Yes, BD242C shares identical TO-220 package dimensions, pin assignment (Base–Collector–Emitter), and mechanical footprint with BD242A and BD242B. All variants differ only in voltage ratings and minor parameter tolerances-not physical layout or terminal function. No PCB changes are needed when upgrading from BD242B to BD242C.

What is the typical DC current gain (h_FE) of BD242C at 3 A collector current?

The BD242C specifies h_FE ≥ 10 (minimum) at V_CE = 4 V and I_C = 3 A. Typical h_FE is not published, but minimum guaranteed gain ensures predictable base drive requirements. For precise gain characterization, users should measure individual units under actual operating conditions due to process variation.

Does BD242C have an integrated base-emitter resistor?

No, BD242C is a standard discrete NPN bipolar transistor without any integrated resistors. It requires external base biasing components-such as current-limiting resistors or active driver circuits-to establish proper operating point. This distinguishes it from digital transistors (e.g., NSD series) that embed built-in resistors.

Can BD242C be used in parallel for higher current handling?

BD242C is not recommended for direct paralleling without individual emitter resistors or active current-sharing circuitry. Variations in h_FE and V_BE between units can cause unequal current distribution, leading to thermal runaway. If higher current is required, consider a single higher-rated device or implement forced current balancing per ON Semiconductor application guidelines.

BD242C Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: PNP

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

BD242C FAQ

1.How can I place an order for BD242C through Aetrix?

Please submit a Request for Quotation (RFQ) for BD242C 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 BD242C reliable?

The price and inventory of BD242C are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BD242C is usually 5 days.

3.What payment methods are accepted for BD242C?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BD242C transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BD242C?

BD242C orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BD242C 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 BD242C?

For technical support, including BD242C datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BD242C requirements.

6.How does Aetrix verify that BD242C is sourced from the original manufacturer or authorized distributors?

All BD242C 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 BD242C meets industry standards.

7.What is the process for return or replacement of BD242C?

All BD242C units undergo pre-shipment inspection (PSI). If there is an issue with BD242C, 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 BD242C part is unused and in its original packaging.

Return procedure for BD242C:

1.Submit a request within 90 days.

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

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