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

onsemi MJE18002

Name: MJE18002
Brand: onsemi
SKU: MJE18002
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MJE18002

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: MJE18002.pdf

Description:: TRANS NPN 450V 2A TO-220

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Product details

Overview

MJE18002G from onsemi is an NPN bipolar power transistor optimized for high-voltage switching in 220 V line-operated switch-mode power supplies and electronic light ballasts, featuring V_CEO = 450 V, I_C = 2.0 A continuous, P_D = 50 W at T_C = 25°C, and fast switching with t_off ≤ 2.5 µs at 125°C.

For engineers reviewing the MJE18002G datasheet, pinout, applications, or equivalent options, this device is selected for high-efficiency, low-base-drive switching in offline SMPS where ruggedness, tight parametric distribution, and Pb-free TO-220AB packaging are required.

Technical Context

The MJE18002G employs a state-of-the-art die designed specifically for hard-switched, inductive-load applications in AC/DC converters. Its high V_CES = 1000 V enables robust operation under voltage transients, while its flat h_FE (11–34 at I_C = 0.2–1.0 A) supports stable forced-beta drive across temperature.

Dynamic saturation behavior is characterized up to 3.0 s post-turn-on, with V_CE(dsat) ≤ 8.0 V at 125°C - critical for minimizing conduction loss during extended switching transitions in ballast circuits. The absence of current tail eliminates need for base-coil turn-off circuitry.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	450 V - Sustains 450 V collector-emitter voltage under switching conditions without breakdown, enabling use in 220 VAC-derived topologies.
I_C (continuous)	2.0 A - Supports sustained output currents up to 2 A in primary-side switching, suitable for 50–100 W SMPS designs.
P_D @ T_C = 25°C	50 W - Maximum dissipation at case temperature 25°C; derates linearly at 0.4 W/°C above 25°C for thermal design margining.
t_off (inductive)	≤ 2.75 µs - Turn-off time under clamped inductive load (V_Z = 300 V, L = 200 µH), directly impacting switching loss and frequency capability.
h_FE @ I_C = 1.0 A	6.0–20 - DC current gain range ensures predictable base drive sizing for forced-beta operation in high-reliability ballast control.
R_JC	2.5 °C/W - Junction-to-case thermal resistance enables effective heatsinking via TO-220 mounting, limiting ΔT_JC to 125°C at full 50 W dissipation.
C_ob	35–60 pF - Output capacitance determines turn-on energy loss and resonant behavior in flyback/snubberless topologies.

Pinout & Package

Package: TO-220AB (Case 221A-09, Style 1), standard through-hole power package with electrically isolated tab, rated for 260°C lead-soldering (5 sec, 1/8″ from case).

Pin/Terminal	Circuit Role	Design Meaning
Collector (Tab)	Main high-current, high-voltage output terminal	Electrically connected to metal tab; must be insulated from heatsink unless system ground reference permits direct mounting.
Base	Control input for transistor turn-on/turn-off	Low-impedance drive required; no external coil needed for turn-off due to fast storage-time suppression (t_si ≤ 2.75 µs).
Emitter	Current return path and reference node	Serves as common emitter for grounded-emitter switching configuration; supports 2.0 A continuous current flow.

Key Features

Feature	Design Value
No base coil required for turn-off	Eliminates discrete inductor in base drive, reducing BOM count and PCB area in compact ballast and SMPS designs.
High and flat h_FE across I_C range	Enables consistent forced-beta operation (IC/IB = 5–10) over 0.2–1.0 A, simplifying gate/base driver design and improving efficiency stability.
Tight lot-to-lot parametric distribution	Reduces production binning and calibration overhead in high-volume lighting and power supply manufacturing.
Pb-free and RoHS-compliant	Meets global environmental compliance requirements without performance trade-offs; marked with "G" suffix per ordering code.

Applications

Compact Fluorescent Lamp (CFL) Ballasts	Offline Flyback SMPS
Use Scenario: High-frequency resonant inverter driving lamp electrodes in 11–30 W CFLs. IC Role / Device Role / Timing Role: Primary-side NPN switch controlling resonant tank current; operates at 20–60 kHz with hard switching. Use Value: Fast t_off ≤ 2.75 µs and low V_CE(sat) ≤ 0.5 V reduce switching and conduction losses, extending lamp life and improving lumen maintenance.	Use Scenario: Primary-side switching transistor in universal-input (85–265 VAC), 30–60 W flyback converters for consumer adapters. IC Role / Device Role / Timing Role: Main power switch handling 300 V clamp conditions during MOSFET replacement in cost-sensitive designs. Use Value: V_CES = 1000 V withstands reflected transients and surge events without snubber augmentation, lowering component count.
LED Driver Power Stages	Industrial AC/DC Auxiliary Supplies
Use Scenario: Constant-current buck-boost or SEPIC stage powering high-brightness LED strings from rectified AC. IC Role / Device Role / Timing Role: Switching element in isolated or non-isolated topology operating at 40–100 kHz with inductive loads. Use Value: Low dynamic saturation voltage (V_CE(dsat) ≤ 3.8 V at 3.0 s, 125°C) maintains regulation accuracy under thermal stress in enclosed fixtures.	Use Scenario: 12–24 V auxiliary supply for PLC I/O modules, motor drives, or HVAC controllers powered from 3-phase 400 VAC mains. IC Role / Device Role / Timing Role: Primary-side switch in forward or half-bridge derived converter handling high-line surges and long-term reliability demands. Use Value: Tight parametric distributions and 150°C max junction temperature rating ensure stable operation across industrial ambient ranges (−40°C to +85°C).

Compact Fluorescent Lamp (CFL) Ballasts

Offline Flyback SMPS

Use Scenario: High-frequency resonant inverter driving lamp electrodes in 11–30 W CFLs.

IC Role / Device Role / Timing Role: Primary-side NPN switch controlling resonant tank current; operates at 20–60 kHz with hard switching.

Use Value: Fast t_off ≤ 2.75 µs and low V_CE(sat) ≤ 0.5 V reduce switching and conduction losses, extending lamp life and improving lumen maintenance.

Use Scenario: Primary-side switching transistor in universal-input (85–265 VAC), 30–60 W flyback converters for consumer adapters.

IC Role / Device Role / Timing Role: Main power switch handling 300 V clamp conditions during MOSFET replacement in cost-sensitive designs.

Use Value: V_CES = 1000 V withstands reflected transients and surge events without snubber augmentation, lowering component count.

LED Driver Power Stages

Industrial AC/DC Auxiliary Supplies

Use Scenario: Constant-current buck-boost or SEPIC stage powering high-brightness LED strings from rectified AC.

IC Role / Device Role / Timing Role: Switching element in isolated or non-isolated topology operating at 40–100 kHz with inductive loads.

Use Value: Low dynamic saturation voltage (V_CE(dsat) ≤ 3.8 V at 3.0 s, 125°C) maintains regulation accuracy under thermal stress in enclosed fixtures.

Use Scenario: 12–24 V auxiliary supply for PLC I/O modules, motor drives, or HVAC controllers powered from 3-phase 400 VAC mains.

IC Role / Device Role / Timing Role: Primary-side switch in forward or half-bridge derived converter handling high-line surges and long-term reliability demands.

Use Value: Tight parametric distributions and 150°C max junction temperature rating ensure stable operation across industrial ambient ranges (−40°C to +85°C).

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJE13003G	V_CEO = 400 V (50 V lower), I_C = 1.5 A (0.5 A lower), R_JC = 3.0 °C/W (0.5 °C/W higher)	Less suited for 220 VAC systems with high transient margins; limited to ≤ 40 W SMPS or lower-power ballasts.	Select when lower cost and reduced voltage headroom are acceptable, and thermal budget allows higher junction rise.
BUL128D	V_CEO = 700 V (250 V higher), I_C = 3.0 A (1.0 A higher), TO-220FP package (isolated tab)	Better surge immunity and higher current capacity, but slower t_off (~4 µs) increases switching loss at >30 kHz.	Prefer for 400 VAC industrial inputs or designs requiring enhanced ruggedness, accepting trade-off in high-frequency efficiency.

Compared with MJE13003G and BUL128D, the MJE18002G delivers optimal balance of 450 V blocking, 2.0 A current, and sub-3 µs turn-off for cost-sensitive, thermally constrained 220 VAC switch-mode applications - especially where fast dynamic saturation and RoHS compliance are mandatory.

Availability

MJE18002G is available at Aetrix Electronics and suitable for switch-mode power supplies, electronic light ballasts, and industrial AC/DC auxiliary supplies requiring stable component supply, Pb-free compliance, and TO-220AB mechanical compatibility.

Supply support for MJE18002G 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 MJE18002G belongs to onsemi's legacy bipolar power transistor product line, engineered for high-reliability, high-voltage switching in offline power conversion - emphasizing ruggedness, thermal stability, and ease of drive in cost-driven lighting and adapter markets.

FAQ

What is the maximum junction temperature rating for the MJE18002G?

The MJE18002G has a maximum junction temperature (T_J) rating of 150°C, as specified in its Absolute Maximum Ratings table. This allows reliable operation in high-ambient environments such as enclosed CFL ballasts or industrial power supplies, provided thermal design maintains T_J ≤ 150°C using the stated R_JC = 2.5 °C/W and appropriate heatsinking. The MJE18002G datasheet confirms this limit applies across all operating conditions.

Does the MJE18002G require a base coil for turn-off?

No, the MJE18002G does not require a base coil for turn-off - a key feature highlighted in its official datasheet. Its internal die design suppresses current tail, enabling clean, rapid turn-off with only resistive base drive. This eliminates the need for external inductors in the base circuit, simplifying layout and reducing component count in SMPS and ballast designs using the MJE18002G.

What is the safe operating area (SOA) limitation for the MJE18002G under inductive switching?

The MJE18002G specifies a reverse-biased safe operating area (RBSOA) for inductive switching, validated under clamped conditions (V_Z = 300 V, L = 500 µH, T_C ≤ 125°C). At 10 µs pulse width, it supports up to ~1.2 A at 300 V; derating is required for longer pulses or higher temperatures. This RBSOA data is explicitly plotted in Figure 16 of the MJE18002G datasheet and defines the absolute boundary for reliable inductive turn-off without avalanche stress.

How does the MJE18002G compare to MOSFETs in switch-mode power supply applications?

The MJE18002G offers lower gate drive complexity and zero gate charge versus MOSFETs, making it suitable for simple, low-cost drivers in <60 kHz SMPS. However, it exhibits higher conduction loss (V_CE(sat) ≥ 0.2 V) and slower switching than modern MOSFETs. For designs prioritizing efficiency above 50 kHz or needing <100 ns transitions, a MOSFET may be preferred - but the MJE18002G remains advantageous where drive simplicity, surge tolerance (V_CES = 1000 V), and cost dominate, as confirmed in MJE18002G application notes.

Is the MJE18002G pin-compatible with other TO-220 NPN transistors like the MJE13003?

The MJE18002G uses standard TO-220AB pinout (Collector-Base-Emitter, left-to-right with tab facing outward), matching mechanical and footprint compatibility with MJE13003G and similar devices. However, electrical differences - including higher V_CEO (450 V vs. 400 V), higher I_C (2.0 A vs. 1.5 A), and faster switching - mean direct substitution requires validation of voltage margin, thermal design, and drive strength. The MJE18002G datasheet does not claim pin-to-pin interchangeability.

MJE18002 Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: SWITCHMODE™

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 2 A

Voltage - Collector Emitter Breakdown (Max):: 450 V

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 200mA, 1A

Current - Collector Cutoff (Max):: 100µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 14 @ 200mA, 5V

Power - Max:: 50 W

Frequency - Transition:: 13MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

MJE18002 FAQ

1.How can I place an order for MJE18002 through Aetrix?

Please submit a Request for Quotation (RFQ) for MJE18002 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 MJE18002 reliable?

The price and inventory of MJE18002 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJE18002 is usually 5 days.

3.What payment methods are accepted for MJE18002?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJE18002 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MJE18002?

MJE18002 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MJE18002 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 MJE18002?

For technical support, including MJE18002 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJE18002 requirements.

6.How does Aetrix verify that MJE18002 is sourced from the original manufacturer or authorized distributors?

All MJE18002 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 MJE18002 meets industry standards.

7.What is the process for return or replacement of MJE18002?

All MJE18002 units undergo pre-shipment inspection (PSI). If there is an issue with MJE18002, 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 MJE18002 part is unused and in its original packaging.

Return procedure for MJE18002:

1.Submit a request within 90 days.

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

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