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

onsemi MJE5731A

Name: MJE5731A
Brand: onsemi
SKU: MJE5731A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MJE5731A

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: MJE5731A.pdf

Description:: TRANS PNP 375V 1A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:2,071

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Product details

Overview

MJE5731A from onsemi is a high-voltage PNP silicon plastic power transistor in TO-220 package, rated for 375 V_CEO, 1.0 A continuous collector current, and 40 W total device dissipation at T_C = 25°C. It serves as a line-operated audio output amplifier stage and switch-mode power supply driver.

For engineers reviewing the MJE5731A datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO = 375 V, h_FE ≥ 10 (at I_C = 1.0 A), V_CE(sat) ≤ 1.0 V, R_JC = 3.125 °C/W, and TO-220 thermal derating behavior.

Technical Context

The MJE5731A operates as a medium-power PNP bipolar junction transistor optimized for linear and switching applications requiring high breakdown voltage and robust safe operating area (SOA). Its SOA is defined by thermal limits up to 150°C junction temperature and second-breakdown constraints under pulsed inductive loads.

It features a DC current gain (h_FE) of 10–150 depending on bias conditions, f_T = 10 MHz, and low saturation voltage (V_CE(sat) ≤ 1.0 V at I_C/I_B = 5), enabling efficient switching in SMPS and audio output stages with minimal conduction loss.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	375 Vdc - supports operation in 300–400 V line-referenced circuits without breakdown
I_C (cont.)	1.0 Adc - delivers sufficient drive for medium-power audio outputs and SMPS gate drivers
P_D @ 25°C	40 W - enables high-power dissipation with heatsink mounting in TO-220 package
R_JC	3.125 °C/W - allows predictable thermal design with case temperature monitoring
h_FE	10 min @ I_C = 1.0 A - ensures reliable base drive sizing for saturated switching
V_CE(sat)	≤ 1.0 V @ I_C = 1.0 A, I_B = 0.2 A - minimizes conduction loss in linear and switching modes
f_T	10 MHz - supports stable operation in audio-frequency and low-MHz switching applications

Pinout & Package

Package: TO-220 (Case 221A-09, Style 1), with metal tab electrically connected to collector (pins 2 and 4).

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control input for forward-biased PNP operation; requires negative drive relative to emitter
2	Collector	Main high-voltage current sink terminal; internally bonded to metal tab for thermal and electrical connection
3	Emiter	Common reference terminal; connects to positive rail in typical PNP switch configuration
4	Collector	Second collector connection for enhanced current handling and thermal path redundancy

Key Features

Feature	Design Value
High V_CEO rating	375 V enables use in 230 VAC line-derived supplies and CRT horizontal deflection circuits
TO-220 plastic package	Industry-standard mechanical interface with integrated heatsink tab for cost-effective thermal management
PNP complement to TIP47–TIP50 series	Enables matched push-pull designs with NPN counterparts in audio and power stages
Pb-free and RoHS compliant	Meets global environmental compliance requirements without performance trade-offs
Unclamped inductive energy rating	20 mJ supports reliable switching into reactive loads like relay coils and transformer primaries

Applications

Audio Output Amplifier	Switch-Mode Power Supply Driver
Use Scenario: Medium-power Class-B or Class-AB audio output stage driving 4–8 Ω speakers in consumer AV receivers. IC Role / Device Role / Timing Role: PNP output transistor delivering peak currents up to 3 A in complementary pair configuration. Use Value: High V_CEO (375 V) prevents breakdown during speaker transient overloads and flyback spikes.	Use Scenario: Gate driver stage for high-side N-channel MOSFETs in offline flyback or forward converters. IC Role / Device Role / Timing Role: Saturated PNP switch sourcing current to MOSFET gate during turn-on. Use Value: Low V_CE(sat) (≤1.0 V) and fast switching (t_r/t_f < 15 ns) minimize gate drive losses and improve efficiency.
Line-Operated Power Regulator	Industrial Relay/Contactor Driver
Use Scenario: Series pass element in discrete 24–48 V regulated supplies derived from rectified AC mains. IC Role / Device Role / Timing Role: Linear regulator pass transistor dissipating up to 40 W with heatsink. Use Value: 40 W PD rating and 3.125 °C/W R_JC allow stable thermal operation under sustained load.	Use Scenario: Direct drive of 24 VDC industrial relays and contactor coils with inductive kick suppression. IC Role / Device Role / Timing Role: Switching transistor absorbing unclamped inductive energy during coil de-energization. Use Value: 20 mJ unclamped inductive energy rating protects against voltage overshoot without external snubbers.

Audio Output Amplifier

Switch-Mode Power Supply Driver

Use Scenario: Medium-power Class-B or Class-AB audio output stage driving 4–8 Ω speakers in consumer AV receivers.

IC Role / Device Role / Timing Role: PNP output transistor delivering peak currents up to 3 A in complementary pair configuration.

Use Value: High V_CEO (375 V) prevents breakdown during speaker transient overloads and flyback spikes.

Use Scenario: Gate driver stage for high-side N-channel MOSFETs in offline flyback or forward converters.

IC Role / Device Role / Timing Role: Saturated PNP switch sourcing current to MOSFET gate during turn-on.

Use Value: Low V_CE(sat) (≤1.0 V) and fast switching (t_r/t_f < 15 ns) minimize gate drive losses and improve efficiency.

Line-Operated Power Regulator

Industrial Relay/Contactor Driver

Use Scenario: Series pass element in discrete 24–48 V regulated supplies derived from rectified AC mains.

IC Role / Device Role / Timing Role: Linear regulator pass transistor dissipating up to 40 W with heatsink.

Use Value: 40 W PD rating and 3.125 °C/W R_JC allow stable thermal operation under sustained load.

Use Scenario: Direct drive of 24 VDC industrial relays and contactor coils with inductive kick suppression.

IC Role / Device Role / Timing Role: Switching transistor absorbing unclamped inductive energy during coil de-energization.

Use Value: 20 mJ unclamped inductive energy rating protects against voltage overshoot without external snubbers.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP high-voltage power transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJE5731	V_CEO = 350 V (25 V lower); otherwise identical pinout, package, and SOA	Suitable where 350 V margin suffices; not recommended for 375 V design margins	Select MJE5731A when full 375 V rating is required for safety margin or regulatory compliance
TIP42C	V_CEO = 100 V; lower power (65 W), different h_FE range (15–75), same TO-220 package	Limited to low-voltage DC-DC and logic-level switching; cannot replace in line-referenced circuits	Choose only for legacy 100 V systems; not a functional substitute for MJE5731A's high-voltage capability

Compared with MJE5731 and TIP42C, the MJE5731A provides the highest V_CEO (375 V) and matches the thermal and switching performance needed for modern high-voltage switching and audio applications-making it the only option among the three qualified for 300+ VAC-derived designs.

Availability

MJE5731A is available at Aetrix Electronics and suitable for switch-mode power supply drivers, audio output amplifiers, and line-operated power regulators requiring stable component supply and long-term industrial availability.

Supply support for MJE5731A 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 manufacturer specializing in energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, and IoT applications.

The MJE5731A belongs to onsemi's high-voltage discrete transistor product line, engineered specifically for ruggedized switching and linear power applications in AC-line-connected equipment and industrial controls.

FAQ

What is the maximum collector-emitter voltage rating for the MJE5731A?

The MJE5731A has a maximum collector-emitter sustaining voltage (V_CEO(sus)) of 375 Vdc at I_C = 30 mA and I_B = 0. This rating is confirmed in the "Electrical Characteristics" table of the official onsemi datasheet (Rev. 9, October 2024) and defines the absolute upper limit for safe DC operation before avalanche breakdown occurs. Exceeding this voltage risks permanent device failure.

Is the MJE5731A pin-compatible with the MJE5731 and MJE5730?

Yes, the MJE5731A shares identical TO-220 package dimensions, pin assignment (Style 1: Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter, Pin 4 = Collector), and mechanical footprint with MJE5730 and MJE5731. All three devices use the same Case 221A-09 outline and are interchangeable at the PCB layout level-only electrical ratings differ.

What is the thermal resistance from junction to case for the MJE5731A?

The MJE5731A has a maximum thermal resistance from junction to case (R_JC) of 3.125 °C/W, as specified in the "Thermal Characteristics" section of the onsemi datasheet. This value assumes proper mounting with thermal compound and adequate heatsink contact; actual system R_JA will depend on heatsink size, airflow, and interface quality.

Does the MJE5731A support inductive load switching without external snubbing?

The MJE5731A is rated for 20 mJ of unclamped inductive load energy (per Figure 10 test condition), meaning it can safely absorb flyback energy from moderate inductive loads-such as relay coils or small transformers-without external snubbers. However, repeated operation near this limit requires careful SOA validation per the datasheet's Figure 5 curves.

What is the minimum DC current gain (h_FE) of the MJE5731A at 1.0 A collector current?

The minimum DC current gain (h_FE) for the MJE5731A is 10, measured at I_C = 1.0 A and V_CE = 10 Vdc (25°C), as stated in the "Electrical Characteristics" table. This ensures predictable base drive requirements in saturated switching applications, though actual gain may reach 150 at lower currents (I_C = 0.3 A).

MJE5731A 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):: 1 A

Voltage - Collector Emitter Breakdown (Max):: 375 V

Vce Saturation (Max) @ Ib, Ic:: 1V @ 200mA, 1A

Current - Collector Cutoff (Max):: 1mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 30 @ 300mA, 10V

Power - Max:: 40 W

Frequency - Transition:: 10MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

MJE5731A FAQ

1.How can I place an order for MJE5731A through Aetrix?

Please submit a Request for Quotation (RFQ) for MJE5731A 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 MJE5731A reliable?

The price and inventory of MJE5731A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJE5731A is usually 5 days.

3.What payment methods are accepted for MJE5731A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJE5731A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MJE5731A?

MJE5731A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MJE5731A 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 MJE5731A?

For technical support, including MJE5731A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJE5731A requirements.

6.How does Aetrix verify that MJE5731A is sourced from the original manufacturer or authorized distributors?

All MJE5731A 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 MJE5731A meets industry standards.

7.What is the process for return or replacement of MJE5731A?

All MJE5731A units undergo pre-shipment inspection (PSI). If there is an issue with MJE5731A, 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 MJE5731A part is unused and in its original packaging.

Return procedure for MJE5731A:

1.Submit a request within 90 days.

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

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