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

onsemi MJE5851G

Name: MJE5851G
Brand: onsemi
SKU: MJE5851G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MJE5851G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: MJE5851G.pdf

Description:: TRANS PNP 350V 8A TO-220

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MJE5851G from onsemi is a PNP silicon power transistor designed for high-voltage, high-speed switching in inductive circuits-specifically line-operated switch-mode applications. It features 350 V_CEO(sus), 8 A continuous collector current, 80 W power dissipation at T_C = 25°C, fast fall time (0.11–0.5 µs), and guaranteed inductive switching performance at 100°C.

For engineers reviewing the MJE5851G datasheet, pinout, applications, or equivalent options, this device is selected for demanding power-switching roles where clamped inductive turn-off robustness, reverse-biased SOA compliance, and thermal stability up to +150°C junction temperature are critical design requirements.

Technical Context

The MJE5851G operates as a high-voltage PNP bipolar junction transistor optimized for hard-switched inductive loads, with base-emitter forward bias during conduction and controlled reverse bias during turn-off. Its safe operating area is explicitly characterized for both forward-bias (second breakdown limited) and reverse-bias (RBSOA) conditions under clamped inductive switching at 100°C.

Dynamic performance is defined using inductive test waveforms: voltage storage time (t_sv), crossover time (t_c), and current fall time (t_fi)-all measured with I_C = 4 A, V_CEM = 250 V, I_B1 = 1.0 A, and V_BE(off) = 5 V. Thermal resistance R_JC is 1.25°C/W, enabling predictable junction-to-case power dissipation modeling.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO(sus)	350 Vdc - Sustains 350 V collector-emitter voltage with IB = 0, defining maximum inductive flyback voltage capability
I_C (continuous)	8.0 Adc - Supports sustained load currents up to 8 A at T_C = 25°C before derating
P_D @ T_C = 25°C	80 W - Maximum power dissipation with heatsink; derates 0.640 W/°C above 25°C case temperature
t_fi (inductive)	0.1 µs (typ) - Fast current fall time under clamped inductive load, minimizing switching loss during turn-off
R_JC	1.25 °C/W - Enables precise junction temperature estimation from measured case temperature in thermal design
T_J range	−65 to +150°C - Fully specified operation across industrial and extended-temperature environments
h_FE @ I_C = 2 A	15 (min) - Ensures sufficient DC current gain for reliable base drive sizing in linear or quasi-saturated switching

Pinout & Package

Package: TO-220 (Case 221A-09, Style 1), 3-lead through-hole, Pb-free, with collector internally connected to the metal tab for direct heatsinking.

Pin/Terminal	Circuit Role	Design Meaning
1	Base	Control input terminal; requires negative current injection relative to emitter to turn on PNP device
2	Collector	Main power output terminal; electrically tied to metal tab-must be insulated from heatsink unless common collector configuration is used
3	Emiter	Power return/reference terminal; serves as common reference for base drive and load return path
4	Collector	Second collector connection-internally bonded to Pin 2 for enhanced current handling and thermal conduction

Key Features

Feature	Design Value
Clamped inductive SOA (RBSOA)	Guaranteed at 100°C with V_BE(off) = 2–8 V, enabling reliable turn-off under high-energy inductive transients
Fast inductive fall time (t_fi)	0.1 µs typical ensures low switching loss in high-frequency switch-mode supplies (e.g., CRT deflection, SMPS)
100°C performance specification	All key parameters-including saturation voltage, leakage, switching times, and SOA-are tested and guaranteed at 100°C junction
Complementary pairing	Designed as PNP complement to MJE13007 series NPN transistors for push-pull and H-bridge topologies
Robust second-breakdown margin	SOA curves validated for 5 ms pulses and dc operation, supporting high-reliability industrial motor and solenoid control

Applications

Switch-Mode Power Supplies	Line-Operated Inverters
Use Scenario: High-efficiency AC-DC conversion in offline SMPS using flyback or forward topology with 220–240 VAC input. IC Role / Device Role / Timing Role: Main switching transistor handling primary-side high-voltage switching at 20–100 kHz. Use Value: 350 V_CEO(sus) and RBSOA compliance ensure safe clamping of transformer leakage spikes without avalanche stress.	Use Scenario: 50/60 Hz grid-tied or off-grid DC-AC inversion for UPS and solar microinverters. IC Role / Device Role / Timing Role: PNP switch in half-bridge output stage driving transformer-coupled output. Use Value: Fast t_fi (0.1 µs) and low t_c minimize dead-time losses and improve waveform fidelity at line frequency switching.
Deflection Circuits	Solenoid & Relay Drivers
Use Scenario: Horizontal deflection yoke control in CRT-based displays and legacy test equipment. IC Role / Device Role / Timing Role: High-current, high-dV/dt switch managing rapid current reversal in inductive yoke windings. Use Value: Guaranteed t_sv ≤ 3.0 µs at 100°C enables precise timing control and reduces retrace distortion.	Use Scenario: Industrial PLC output modules driving 24–48 VDC solenoids and latching relays. IC Role / Device Role / Timing Role: High-current PNP switch providing controlled turn-on/turn-off with snubberless inductive energy handling. Use Value: 8 A I_C rating and −65°C to +150°C T_J range support ruggedized operation in harsh factory environments.

Switch-Mode Power Supplies

Line-Operated Inverters

Use Scenario: High-efficiency AC-DC conversion in offline SMPS using flyback or forward topology with 220–240 VAC input.

IC Role / Device Role / Timing Role: Main switching transistor handling primary-side high-voltage switching at 20–100 kHz.

Use Value: 350 V_CEO(sus) and RBSOA compliance ensure safe clamping of transformer leakage spikes without avalanche stress.

Use Scenario: 50/60 Hz grid-tied or off-grid DC-AC inversion for UPS and solar microinverters.

IC Role / Device Role / Timing Role: PNP switch in half-bridge output stage driving transformer-coupled output.

Use Value: Fast t_fi (0.1 µs) and low t_c minimize dead-time losses and improve waveform fidelity at line frequency switching.

Deflection Circuits

Solenoid & Relay Drivers

Use Scenario: Horizontal deflection yoke control in CRT-based displays and legacy test equipment.

IC Role / Device Role / Timing Role: High-current, high-dV/dt switch managing rapid current reversal in inductive yoke windings.

Use Value: Guaranteed t_sv ≤ 3.0 µs at 100°C enables precise timing control and reduces retrace distortion.

Use Scenario: Industrial PLC output modules driving 24–48 VDC solenoids and latching relays.

IC Role / Device Role / Timing Role: High-current PNP switch providing controlled turn-on/turn-off with snubberless inductive energy handling.

Use Value: 8 A I_C rating and −65°C to +150°C T_J range support ruggedized operation in harsh factory environments.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJE5852G	Higher V_CEO(sus) = 400 V; otherwise identical package, pinout, and dynamic specs	Better suited for 400 V bus applications (e.g., higher-input industrial SMPS); same thermal and switching behavior	Select when system flyback voltage exceeds 350 V but layout and drive remain unchanged
BDW53C	Lower V_CEO(sus) = 100 V; higher h_FE (25 min); TO-220 package with same pinout (Style 1)	Limited to <100 V applications; not suitable for line-voltage switching; better for low-voltage motor control	Use only in sub-100 V designs where gain and cost outweigh voltage headroom needs

Compared with MJE5852G, the MJE5851G offers lower voltage rating but tighter parameter consistency in 350 V systems; compared with BDW53C, it delivers 3.5× higher blocking voltage at the cost of reduced DC gain-making it irreplaceable in mains-referenced switch-mode topologies.

Availability

MJE5851G is available at Aetrix Electronics and suitable for switch-mode power supplies, line-operated inverters, and industrial solenoid drivers requiring stable component supply, long-term BOM continuity, and traceable sourcing for production ramp-up.

Supply support for MJE5851G 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 MJE5851G belongs to onsemi's Switch-mode Series PNP Silicon Power Transistors product line, engineered specifically for high-reliability, high-voltage inductive switching in line-operated power conversion and deflection systems.

FAQ

What is the maximum collector-emitter sustaining voltage for MJE5851G?

The MJE5851G has a guaranteed minimum collector-emitter sustaining voltage (V_CEO(sus)) of 350 Vdc at I_C = 10 mA and I_B = 0. This rating defines its ability to block voltage during turn-off in inductive switching applications and is validated per the onsemi datasheet Rev. 8. The MJE5851G must not be operated beyond this limit without external clamping.

Does MJE5851G support operation at elevated temperatures?

Yes, the MJE5851G is fully specified from −65°C to +150°C junction temperature. Critical parameters-including V_CE(sat), leakage currents, switching times (t_sv, t_c, t_fi), and RBSOA-are guaranteed at 100°C, making it suitable for thermally demanding applications like enclosed switch-mode power supplies and industrial motor controls where ambient temperatures exceed 85°C.

What is the thermal resistance from junction to case for MJE5851G?

The MJE5851G has a maximum thermal resistance of R_JC = 1.25°C/W, measured from junction to case surface. This value allows engineers to calculate peak junction temperature using T_J(pk) = T_C + (P_D × R_JC). The metal tab (collector) serves as the primary thermal path, requiring proper mechanical mounting and thermal interface material for effective heatsinking.

Is MJE5851G pin-compatible with other transistors in its family?

Yes, the MJE5851G uses TO-220 Case 221A-09 Style 1 pinout (Base–Collector–Emitter–Collector), matching the MJE5850G and MJE5852G. All three share identical mechanical footprint, thermal characteristics, and electrical pin functions-enabling drop-in replacement within their respective voltage ratings without PCB modification.

What does "clamped inductive SOA" mean for MJE5851G?

Clamped inductive SOA (RBSOA) refers to the MJE5851G's validated safe operating area under reverse-biased base-emitter conditions during inductive turn-off, with collector voltage actively clamped (e.g., via TVS or Zener). Per Figure 13 in the datasheet, this ensures the device avoids destructive second breakdown even when sustaining high V_CE and I_C simultaneously-critical for reliability in deflection and SMPS circuits.

MJE5851G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: SWITCHMODE™

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 8 A

Voltage - Collector Emitter Breakdown (Max):: 350 V

Vce Saturation (Max) @ Ib, Ic:: 5V @ 3A, 8A

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: 5 @ 5A, 5V

Power - Max:: 80 W

Frequency - Transition:: -

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

MJE5851G FAQ

1.How can I place an order for MJE5851G through Aetrix?

Please submit a Request for Quotation (RFQ) for MJE5851G 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 MJE5851G reliable?

The price and inventory of MJE5851G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJE5851G is usually 5 days.

3.What payment methods are accepted for MJE5851G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJE5851G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MJE5851G?

MJE5851G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MJE5851G 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 MJE5851G?

For technical support, including MJE5851G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJE5851G requirements.

6.How does Aetrix verify that MJE5851G is sourced from the original manufacturer or authorized distributors?

All MJE5851G 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 MJE5851G meets industry standards.

7.What is the process for return or replacement of MJE5851G?

All MJE5851G units undergo pre-shipment inspection (PSI). If there is an issue with MJE5851G, 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 MJE5851G part is unused and in its original packaging.

Return procedure for MJE5851G:

1.Submit a request within 90 days.

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

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