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onsemi MJF18008G
- Part No.:
- MJF18008G
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-220-3 Full Pack
- Datasheet:
-
MJF18008G.pdf
- Description:
- TRANS NPN 450V 8A TO-220FP
- Quantity:
- Payment:
- Shipping:
Inventory:48
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Product details
Overview
MJF18008G from onsemi is a switch-mode NPN bipolar power transistor designed for high-voltage switching in 220 V line-operated switch-mode power supplies and electronic light ballasts. It delivers 8.0 A continuous collector current, sustains 450 Vdc collector-emitter voltage, and features isolated TO-220 (Case 221D) packaging with 3500 VRMS UL recognition (File #E69369).
For engineers reviewing the MJF18008G datasheet, pinout, applications, or equivalent options, this page provides verified electrical specifications, thermal derating behavior, isolation test configurations, switching timing under resistive/inductive loads, and real-world design implications for ballast and SMPS primary-side switching.
Technical Context
The MJF18008G employs an applications-specific die optimized for fast, efficient hard-switching in high-voltage DC-DC converters and resonant lamp drivers. Its flat hFE curve (6.0–20 at IC = 2–4.5 A, TC = 125 °C) enables stable base drive across load and temperature, while low VCE(sat) (0.3–0.8 V) minimizes conduction loss during saturation.
It supports robust inductive turn-off without tail current due to optimized minority-carrier lifetime control - eliminating need for external base-coil snubbers. The fully isolated TO-220 package (Case 221D) enables direct heatsink mounting with guaranteed 3500 VRMS isolation per UL File E69369, validated under three distinct creepage/strike configurations (Figures 22a–c).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO | 450 Vdc - Withstands peak line voltage + margin in 220 VAC SMPS primary-side switching without breakdown. |
| IC (continuous) | 8.0 Adc - Supports up to 100 W output in typical flyback or forward converter topologies at 100 kHz. |
| VCE(sat) @ IC=4.5A | 0.35–0.7 Vdc - Low saturation voltage reduces conduction loss and junction heating during on-state. |
| toff (inductive) | 1.6–2.5 μs - Enables reliable operation up to ~200 kHz switching frequency with controlled energy dissipation. |
| RJC | 2.78 °C/W - Thermal resistance from junction to case defines heatsink sizing requirement for 45 W PD limit. |
| hFE @ IC=4.5A | 6.0–9.0 - Ensures predictable base drive current (IB ≈ 0.5–0.75 A) for full saturation under worst-case temperature. |
| Isolation Voltage | 3500 VRMS (1 sec, RH < 30%, TA = 25 °C) - Meets reinforced insulation requirements for Class I appliances per UL 60950-1. |
Pinout & Package
Package: TO-220 Fullpak (Case 221D), fully isolated, UL Recognized (File #E69369), Pb-Free (G suffix). Mounting requires screw or clip with ≤10 in·lbs torque to preserve isolation integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control input; requires 0.9 A peak drive for 4.5 A collector current; low VBE(sat) (0.92–1.25 V) eases driver selection. |
| 2 | Emitter | Power return node; electrically isolated from heatsink; must be routed with low-inductance path to minimize switching overshoot. |
| 3 | Collector | Main power output; connects to primary winding or clamp network; rated for 1000 VCES blocking capability. |
Key Features
| Feature | Design Value |
|---|---|
| No base coil required for turn-off | Eliminates snubber inductors and associated PCB area/cost; simplifies gate/base drive circuitry in ballast designs. |
| Tight parametric distributions | Enables consistent batch-to-batch performance in high-volume lighting and power supply manufacturing. |
| UL-recognized isolation | Validated 3500 VRMS isolation supports safety-critical Class I equipment without additional barrier components. |
| High hFE at elevated temperature | hFE ≥ 6.0 at TC = 125 °C ensures reliable saturation even in thermally constrained enclosures. |
| Pb-Free & RoHS compliant | Meets global environmental regulations; compatible with standard lead-free reflow soldering profiles (TL = 260 °C). |
Applications
| Electronic Fluorescent Lamp (EFL) Ballast | AC-DC Switch-Mode Power Supply |
|---|---|
|
Use Scenario: High-frequency (25–60 kHz) resonant inverter driving 4–8 ft T8/T12 fluorescent lamps in commercial lighting fixtures. IC Role / Device Role / Timing Role: Primary-side switching transistor in half-bridge topology; handles 300–400 VDC bus with inductive flyback energy recovery. Use Value: Fast tsi (2.0–3.2 μs) and low VCE(dsat) reduce switching losses and audible noise; UL isolation eliminates need for reinforced transformer barriers. |
Use Scenario: 65–100 W offline flyback converter powering industrial control modules or IoT gateways from 220 VAC mains. IC Role / Device Role / Timing Role: Main power switch in primary-side regulation; operates at 65–130 kHz with DCM/CCM boundary control. Use Value: 450 V VCEO margin accommodates 385 VDC bulk capacitor ripple; 8 A IC rating supports peak power surges without derating. |
| LED Driver (High-Power) | UPS Inverter Stage |
|
Use Scenario: Constant-current LED driver for street lighting (100–200 W) using LLC resonant topology with PFC front-end. IC Role / Device Role / Timing Role: Half-bridge switching device handling 400 VDC bus; synchronized with zero-voltage switching (ZVS) controller. Use Value: Flat hFE vs. IC curve ensures stable gain during ZVS transitions; low Cob (100–150 pF) minimizes capacitive coupling losses at 200–500 kHz. |
Use Scenario: Line-interactive UPS inverter stage converting 360–400 VDC battery bank to 220 VAC output during grid failure. IC Role / Device Role / Timing Role: High-side switch in H-bridge inverter; subjected to repetitive inductive turn-off stress with clamped voltage. Use Value: Reverse-bias SOA validated per Figure 16 supports safe operation under clamped 300 V conditions; 2.78 °C/W RJC enables compact heatsinking. |
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 |
|---|---|---|---|
| MJE18008G | Non-isolated TO-220AB (Case 221A); RJC = 1.0 °C/W; PD = 125 W; no UL isolation rating. | Suitable for cost-sensitive, non-safety-critical SMPS where heatsink is not user-accessible. | Select when isolation is unnecessary and higher power dissipation is required in space-constrained layouts. |
| ST13007D | 8 A / 400 V NPN; TO-220FP package; hFE = 8–25; RJC = 2.5 °C/W; no UL recognition. | Used in consumer-grade adapters; lacks documented 3500 VRMS isolation validation. | Consider only if UL certification is not mandated and thermal margin allows for slightly lower VCEO rating. |
Compared with MJE18008G and ST13007D, the MJF18008G uniquely combines UL-verified isolation, 450 V VCEO headroom, and tight hFE distribution - making it the only choice for certified ballast and industrial SMPS designs requiring reinforced insulation and consistent switching behavior across production lots.
Availability
MJF18008G is available at Aetrix Electronics and suitable for electronic ballasts, AC-DC switch-mode power supplies, and high-power LED drivers requiring stable component supply, long-term lifecycle support, and certified isolation compliance.
Supply support for MJF18008G 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 MJF18008G belongs to onsemi's high-voltage bipolar power transistor family engineered specifically for reliability-critical switching applications in lighting and power conversion - emphasizing low drive loss, thermal stability, and safety-certified packaging.
FAQ
What is the maximum continuous collector current rating for MJF18008G?
The MJF18008G is rated for 8.0 Adc continuous collector current at TC = 25 °C. Derating is required above 25 °C at 0.36 W/°C, limiting usable current in high-temperature environments. This rating is validated under forced-air or heatsink-cooled conditions per Figure 17 of the datasheet, and reflects actual conduction capability in sustained switching operation - not pulsed peak limits.
Does MJF18008G require a base drive coil for turn-off?
No, the MJF18008G does not require a base drive coil for turn-off. Its internal die design eliminates current tail during switching transitions, enabling clean, fast turn-off with simple resistor-based or active base drive circuits. This feature is explicitly confirmed in the datasheet's "Features" section and validated by measured tsi and tfi waveforms in Figures 9–11.
What is the UL recognition status of MJF18008G?
The MJF18008G is UL Recognized at 3500 VRMS (File #E69369) for isolation testing per Figures 22a–c. This applies specifically to the TO-220 Fullpak (Case 221D) package with proper mounting - including minimum creepage distances and ≤10 in·lbs screw torque. Recognition covers one-second withstand voltage under controlled humidity and temperature conditions.
How does the thermal resistance of MJF18008G compare to MJE18008G?
The MJF18008G has a junction-to-case thermal resistance (RJC) of 2.78 °C/W, significantly higher than the MJE18008G's 1.0 °C/W. This difference arises directly from the MJF18008G's fully isolated construction, which adds thermal barrier layers. As a result, the MJF18008G's total device dissipation is rated at 45 W (vs. 125 W for MJE18008G), demanding more conservative heatsink design.
Can MJF18008G be used in inductive load switching applications?
Yes, the MJF18008G is explicitly characterized for inductive load switching, with published data for tsi (storage time), tfi (fall time), and tc (crossover time) under clamped 300 V conditions (Figures 9–14). Its reverse-bias safe operating area (RBSOA) is validated per Figure 16, confirming suitability for ballast and UPS inverter stages where simultaneous high voltage and current occur during turn-off.
MJF18008G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- SWITCHMODE™
- Package/Case:
- TO-220-3 Full Pack
- Packaging:
- Tube
- Product Status:
- Active
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 8 A
- Voltage - Collector Emitter Breakdown (Max):
- 450 V
- Vce Saturation (Max) @ Ib, Ic:
- 700mV @ 900mA, 4.5V
- Current - Collector Cutoff (Max):
- 100µA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 14 @ 1A, 5V
- Power - Max:
- 45 W
- Frequency - Transition:
- 13MHz
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220FP
MJF18008G FAQ
1.How can I place an order for MJF18008G through Aetrix?
Please submit a Request for Quotation (RFQ) for MJF18008G 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 MJF18008G reliable?
The price and inventory of MJF18008G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJF18008G is usually 5 days.
3.What payment methods are accepted for MJF18008G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJF18008G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MJF18008G?
MJF18008G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MJF18008G 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 MJF18008G?
For technical support, including MJF18008G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJF18008G requirements.
6.How does Aetrix verify that MJF18008G is sourced from the original manufacturer or authorized distributors?
All MJF18008G 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 MJF18008G meets industry standards.
7.What is the process for return or replacement of MJF18008G?
All MJF18008G units undergo pre-shipment inspection (PSI). If there is an issue with MJF18008G, 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 MJF18008G part is unused and in its original packaging.
Return procedure for MJF18008G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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