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

onsemi MJE703

Name: MJE703
Brand: onsemi
SKU: MJE703
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MJE703

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-225AA, TO-126-3

Datasheet:: MJE703.pdf

Description:: TRANS PNP DARL 80V 4A TO-126

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MJE703 from onsemi is a PNP silicon Darlington power transistor in TO-225 package, rated for 80 V_CEO, 4.0 A collector current, and 40 W power dissipation at T_C = 25°C, with typical DC current gain (h_FE) of 750 at I_C = 2.0 A and V_CE = 3.0 V - used in low-speed switching and linear amplifier stages for industrial control and power supply output stages.

For engineers reviewing the MJE703 datasheet, pinout, applications, or equivalent options, key selection considerations include its PNP polarity, built-in base-emitter resistors limiting leakage multiplication, thermal resistance R_JC = 3.12°C/W, safe operating area limitations at high T_C, and compatibility with TO-225 heatsink mounting in discrete power stage designs.

Technical Context

The MJE703 operates as a monolithic PNP Darlington pair with integrated base-emitter shunt resistors to suppress leakage-induced multiplication effects. Its 80 V_CEO rating and 4.0 A continuous collector current support operation in medium-voltage, medium-current linear and switching applications up to 150°C junction temperature.

Thermal design relies on case-to-heatsink conduction (R_JC = 3.12°C/W), while ambient derating follows 0.32 W/°C above 25°C. Safe operating area (SOA) is limited by second breakdown at high V_CE/I_C combinations and thermally at elevated case temperatures, per Figures 5 and 7 in the datasheet.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	80 Vdc - maximum collector-emitter voltage before breakdown under open-base conditions; defines upper rail limit in PNP switch or amplifier configurations.
I_C	4.0 Adc - continuous collector current rating at T_C = 25°C; determines load-handling capability in relay drivers or regulator pass elements.
P_D	40 W - total power dissipation at T_C = 25°C; sets thermal budget for heatsink sizing in linear-mode operation.
h_FE	750 (min) @ I_C = 2.0 A, V_CE = 3.0 V - DC current gain enabling low base drive current (e.g., ~2.7 mA for 2 A output), reducing driver stage loading.
V_CE(sat)	2.8 Vdc (max) @ I_C = 2.0 A, I_B = 40 mA - saturation voltage defining conduction loss and heat generation in switching applications.
R_JC	3.12 °C/W - junction-to-case thermal resistance; directly determines temperature rise from die to heatsink interface under steady-state power.

Pinout & Package

Package: TO-225 (Case 77-09, Style 1), plastic through-hole package with metal tab (pins 2 and 4 both connected to collector, pin 1 = emitter, pin 3 = base). Mounting requires electrically isolated heatsink interface due to collector-connected tab.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1	Emitter	Primary current exit path for PNP device; connects to higher potential rail in common-emitter switch or amplifier topologies.
Pins 2 & 4	Collector	Shared collector terminal tied to metal tab; must be electrically isolated from chassis/heatsink unless system ground reference permits direct connection.
Pin 3	Base	Control input for Darlington pair; driven with current-limited source to avoid exceeding I_B(max) = 0.1 Adc and ensure stable turn-on/turn-off.

Key Features

Feature	Design Value
Monolithic Darlington construction	Integrates driver and output transistors on single die, eliminating external interconnects and improving reliability over discrete pairs.
Built-in base-emitter shunt resistors	Suppresses leakage current multiplication at high temperature, preventing thermal runaway in linear operation.
Pb-free and RoHS-compliant packaging	Meets environmental compliance requirements for industrial and consumer equipment without requiring leaded solder processes.
High h_FE (750 min)	Reduces required base drive current by >10× versus standard power transistors, simplifying driver circuitry and lowering gate/base driver losses.

Applications

Industrial Relay Drivers	Linear Voltage Regulator Pass Elements
Use Scenario: Driving 24 VDC industrial relays with coil currents up to 3.5 A in PLC output modules. IC Role / Device Role / Timing Role: PNP Darlington switch controlling relay coil current path from positive rail to ground. Use Value: High h_FE enables direct microcontroller GPIO drive (via series resistor), eliminating need for intermediate small-signal transistor stage.	Use Scenario: Series pass element in adjustable 5–24 V, 3 A linear power supplies for test equipment and analog subsystems. IC Role / Device Role / Timing Role: Current-controlled PNP pass transistor regulating output voltage via feedback loop error amplifier. Use Value: Low V_CE(sat) and high SOA allow stable operation under full-load, short-circuit, and thermal stress without secondary protection circuitry.
DC Motor H-Bridge High-Side Switches	AC Solid-State Relay Output Stages
Use Scenario: High-side switch in 24 V brushed DC motor control for HVAC actuators and valve positioners. IC Role / Device Role / Timing Role: PNP Darlington providing bidirectional current blocking and controlled turn-on/turn-off in half-bridge configuration. Use Value: 80 V_CEO rating accommodates back-EMF spikes during motor commutation without clamping diodes in many cases.	Use Scenario: Output switching stage in opto-isolated AC solid-state relays handling 120/240 VAC loads up to 3 A RMS. IC Role / Device Role / Timing Role: PNP Darlington driving gate of TRIAC or back-to-back SCRs in zero-crossing or random-phase firing circuits. Use Value: Built-in leakage suppression ensures reliable turn-off at elevated ambient temperatures (>85°C) common in enclosed relay enclosures.

Industrial Relay Drivers

Linear Voltage Regulator Pass Elements

Use Scenario: Driving 24 VDC industrial relays with coil currents up to 3.5 A in PLC output modules.

IC Role / Device Role / Timing Role: PNP Darlington switch controlling relay coil current path from positive rail to ground.

Use Value: High h_FE enables direct microcontroller GPIO drive (via series resistor), eliminating need for intermediate small-signal transistor stage.

Use Scenario: Series pass element in adjustable 5–24 V, 3 A linear power supplies for test equipment and analog subsystems.

IC Role / Device Role / Timing Role: Current-controlled PNP pass transistor regulating output voltage via feedback loop error amplifier.

Use Value: Low V_CE(sat) and high SOA allow stable operation under full-load, short-circuit, and thermal stress without secondary protection circuitry.

DC Motor H-Bridge High-Side Switches

AC Solid-State Relay Output Stages

Use Scenario: High-side switch in 24 V brushed DC motor control for HVAC actuators and valve positioners.

IC Role / Device Role / Timing Role: PNP Darlington providing bidirectional current blocking and controlled turn-on/turn-off in half-bridge configuration.

Use Value: 80 V_CEO rating accommodates back-EMF spikes during motor commutation without clamping diodes in many cases.

Use Scenario: Output switching stage in opto-isolated AC solid-state relays handling 120/240 VAC loads up to 3 A RMS.

IC Role / Device Role / Timing Role: PNP Darlington driving gate of TRIAC or back-to-back SCRs in zero-crossing or random-phase firing circuits.

Use Value: Built-in leakage suppression ensures reliable turn-off at elevated ambient temperatures (>85°C) common in enclosed relay enclosures.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJE702G	Same TO-225 package, but rated for V_CEO = 60 V and h_FE = 750 @ I_C = 1.5 A - lower voltage headroom and reduced current gain at higher I_C.	Suitable only where bus voltage ≤ 50 V and peak load current < 3 A; not interchangeable in 80 V systems.	Select MJE702G only if design operates below 60 V and prioritizes cost over margin; verify SOA curves match load profile.
TIP2955	TO-220 package, V_CEO = 100 V, I_C = 15 A, h_FE = 20–70 - higher voltage/current but much lower gain and different thermal interface (isolated tab).	Requires PCB layout change and larger heatsink; suitable for higher-power, lower-gain applications where base drive is robust.	Choose TIP2955 when >80 V operation or >4 A peak current is needed; accept added base drive complexity and mechanical redesign.

Compared with MJE702G, the MJE703 offers +20 V headroom and maintains specified h_FE at higher collector current, making it preferable for 24–48 V industrial systems with dynamic loads; versus TIP2955, MJE703 provides superior current gain and TO-225 mounting compatibility but lower absolute current and voltage ratings.

Availability

MJE703 is available at Aetrix Electronics and suitable for industrial relay drivers, linear voltage regulator pass elements, and DC motor high-side switches requiring stable component supply across extended production lifecycles.

Supply support for MJE703 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, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The MJE703 belongs to onsemi's legacy plastic Darlington power transistor family designed for general-purpose amplifier and low-speed switching applications where high DC gain and thermal stability are critical in cost-sensitive industrial hardware.

FAQ

What is the maximum collector-emitter voltage rating for the MJE703?

The MJE703 has a maximum collector-emitter voltage (V_CEO) rating of 80 Vdc, tested under open-base conditions with I_C = 50 mA. This rating defines the absolute upper limit for voltage applied between collector and emitter in the MJE703's off state and must not be exceeded to prevent avalanche breakdown or permanent damage to the MJE703.

Does the MJE703 include internal base-emitter resistors?

Yes, the MJE703 features monolithic construction with built-in base-emitter shunt resistors to limit leakage-induced multiplication - a key design feature explicitly stated in the official onsemi datasheet for the MJE703. These resistors improve thermal stability and prevent unintended turn-on at elevated junction temperatures, distinguishing the MJE703 from basic power transistors.

What package type does the MJE703 use, and how are its pins configured?

The MJE703 uses the TO-225 package (Case 77-09, Style 1), with pin 1 = emitter, pins 2 and 4 = collector (both internally connected to the metal tab), and pin 3 = base. This configuration requires electrical isolation between the collector tab and heatsink unless system grounding allows direct thermal contact - a critical layout consideration for the MJE703.

What is the minimum DC current gain (h_FE) of the MJE703 under standard test conditions?

The MJE703 guarantees a minimum DC current gain (h_FE) of 750 at I_C = 2.0 A and V_CE = 3.0 V, as specified in the onsemi Electrical Characteristics table. This high gain enables efficient base drive in applications such as relay drivers and linear regulators, reducing the required base current for the MJE703 compared to conventional power transistors.

Is the MJE703 RoHS-compliant and lead-free?

Yes, the MJE703 is marked with suffix "G" indicating Pb-free construction and full RoHS compliance per the onsemi datasheet revision 12 (December 2013). The MJE703 meets EU Directive 2011/65/EU requirements and is suitable for environmentally regulated industrial and consumer end equipment without requiring exemptions.

MJE703 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-225AA, TO-126-3

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: PNP - Darlington

Current - Collector (Ic) (Max):: 4 A

Voltage - Collector Emitter Breakdown (Max):: 80 V

Vce Saturation (Max) @ Ib, Ic:: 2.8V @ 40mA, 2A

Current - Collector Cutoff (Max):: 100µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 750 @ 2A, 3V

Power - Max:: 40 W

Frequency - Transition:: -

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-126

MJE703 FAQ

1.How can I place an order for MJE703 through Aetrix?

Please submit a Request for Quotation (RFQ) for MJE703 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 MJE703 reliable?

The price and inventory of MJE703 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJE703 is usually 5 days.

3.What payment methods are accepted for MJE703?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJE703 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MJE703?

MJE703 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MJE703 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 MJE703?

For technical support, including MJE703 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJE703 requirements.

6.How does Aetrix verify that MJE703 is sourced from the original manufacturer or authorized distributors?

All MJE703 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 MJE703 meets industry standards.

7.What is the process for return or replacement of MJE703?

All MJE703 units undergo pre-shipment inspection (PSI). If there is an issue with MJE703, 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 MJE703 part is unused and in its original packaging.

Return procedure for MJE703:

1.Submit a request within 90 days.

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

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