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

onsemi FJE3303TU

Name: FJE3303TU
Brand: onsemi
SKU: FJE3303TU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: FJE3303TU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: FJE3303TU.pdf

Description:: TRANS NPN 400V 1.5A TO-126-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

FJE3303TU from Fairchild Semiconductor is a high-voltage, fast-switching NPN power transistor rated for 400 V V_CEO, 1.5 A DC collector current, and 20 W collector dissipation at T_C = 25°C; it delivers 4 MHz f_T, 1.1 µs t_ON, and 0.7 µs t_F, and is used in electronic ballast circuits and switching regulators.

For engineers reviewing the FJE3303TU datasheet, pinout, applications, or equivalent options, key selection criteria include breakdown voltage margin (V_CEO = 400 V), switching speed under resistive load (t_STG = 4.0 µs), saturation performance (V_CE(sat) = 1.0 V @ I_C = 1.0 A, I_B = 0.25 A), and TO-126 thermal handling capability.

Technical Context

This device operates as a single NPN bipolar junction transistor optimized for high-voltage switching applications where rapid turn-on/turn-off and robust safe operating area (SOA) are required. It features a minimum h_FE of 8 at I_C = 0.5 A and supports pulse currents up to 3 A with ≤10% duty cycle.

Its 21 pF output capacitance (C_ob) and 4 MHz current gain bandwidth product (f_T) reflect design trade-offs favoring high-voltage ruggedness over RF linearity. The device is characterized across –25°C to +125°C ambient, with derated power dissipation above 25°C per Figure 9.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	400 V - Withstands 400 V between collector and emitter with base open; enables use in 310 V DC bus switching regulator stages.
I_C (DC)	1.5 A - Continuous collector current rating defines maximum steady-state load drive capability at T_C = 25°C.
P_C	20 W - Maximum collector power dissipation at case temperature 25°C; requires heatsinking for sustained operation.
f_T	4 MHz - Current gain bandwidth product indicates usable frequency limit for small-signal amplification or high-speed switching control loops.
t_ON/t_F	1.1 µs / 0.7 µs - Fast turn-on and fall times support >100 kHz switching in ballast and SMPS designs with low switching loss.
C_ob	21 pF - Output capacitance measured at V_CB = 10 V; impacts snubber design and switching node ringing in high-dV/dt applications.

Pinout & Package

Package: TO-126 molded plastic package with integral heat sink tab; pin 1 = Emitter, pin 2 = Collector, pin 3 = Base; tab is electrically connected to collector.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit path for majority carriers	Low-impedance return node; must be routed with low-inductance trace in high-di/dt switching paths.
2 (Collector)	Current entry path; tied to heat sink tab	High-voltage main power terminal; tab connection enables direct mechanical mounting to heatsink without isolation washer.
3 (Base)	Control electrode for minority carrier injection	Requires current-driven bias (not voltage-driven); base resistor selection must ensure I_B ≥ I_C/h_FE(min) across temperature.

Key Features

Feature	Design Value
High-voltage blocking	V_CEO = 400 V and V_CBO = 700 V enable direct interface with rectified 220–240 VAC mains (≈310 V DC).
Fast switching	Combined t_ON + t_STG + t_F < 6 µs allows efficient operation at 50–200 kHz in electronic lamp ballasts.
Robust SOA	Forward-biased SOA curve (Figure 7) supports 1 A pulsed current at 125 V with 1 ms pulse width without second breakdown.
Thermal stability	Junction temperature range –65°C to +150°C and derating curve (Figure 9) support industrial ambient operation up to +125°C.

Applications

Electronic Ballast Control	Switching Regulator Output Stage
Use Scenario: Driving resonant LC tank in 20–60 kHz fluorescent lamp ballasts with 310 V DC bus. IC Role / Device Role / Timing Role: Main switching element in half-bridge or single-ended topology; handles repetitive 310 V, 1 A pulses. Use Value: Low t_F (0.7 µs) minimizes tail current loss; V_CEO = 400 V provides 90 V margin above 310 V bus, reducing risk of avalanche stress.	Use Scenario: Primary-side switch in offline flyback or forward converters delivering 10–30 W at 50–100 kHz. IC Role / Device Role / Timing Role: High-voltage power switch controlling energy transfer from primary winding to secondary. Use Value: 20 W P_C and SOA compliance allow reliable operation at 1.5 A DC with minimal heatsink; h_FE ≥ 8 ensures stable base drive at elevated temperature.
DC Motor Commutation	Inductive Load Switching
Use Scenario: Brushed DC motor driver in HVAC blower or appliance control with 200–300 V supply. IC Role / Device Role / Timing Role: Low-side switch turning motor current on/off; subjected to inductive kickback during turn-off. Use Value: Reverse-biased SOA (Figure 8) supports safe clamping of 200 V inductive spikes with 1 A peak current; V_CBO = 700 V prevents breakdown.	Use Scenario: Solenoid or relay driver in industrial PLC output modules with 24–48 V logic but 200–400 V load side. IC Role / Device Role / Timing Role: High-side or low-side power switch interfacing microcontroller GPIO to high-voltage inductive loads. Use Value: Fast t_ON/t_F reduces dwell time in linear region, lowering conduction loss during switching transitions; TO-126 tab simplifies thermal management in dense layouts.

Electronic Ballast Control

Switching Regulator Output Stage

Use Scenario: Driving resonant LC tank in 20–60 kHz fluorescent lamp ballasts with 310 V DC bus.

IC Role / Device Role / Timing Role: Main switching element in half-bridge or single-ended topology; handles repetitive 310 V, 1 A pulses.

Use Value: Low t_F (0.7 µs) minimizes tail current loss; V_CEO = 400 V provides 90 V margin above 310 V bus, reducing risk of avalanche stress.

Use Scenario: Primary-side switch in offline flyback or forward converters delivering 10–30 W at 50–100 kHz.

IC Role / Device Role / Timing Role: High-voltage power switch controlling energy transfer from primary winding to secondary.

Use Value: 20 W P_C and SOA compliance allow reliable operation at 1.5 A DC with minimal heatsink; h_FE ≥ 8 ensures stable base drive at elevated temperature.

DC Motor Commutation

Inductive Load Switching

Use Scenario: Brushed DC motor driver in HVAC blower or appliance control with 200–300 V supply.

IC Role / Device Role / Timing Role: Low-side switch turning motor current on/off; subjected to inductive kickback during turn-off.

Use Value: Reverse-biased SOA (Figure 8) supports safe clamping of 200 V inductive spikes with 1 A peak current; V_CBO = 700 V prevents breakdown.

Use Scenario: Solenoid or relay driver in industrial PLC output modules with 24–48 V logic but 200–400 V load side.

IC Role / Device Role / Timing Role: High-side or low-side power switch interfacing microcontroller GPIO to high-voltage inductive loads.

Use Value: Fast t_ON/t_F reduces dwell time in linear region, lowering conduction loss during switching transitions; TO-126 tab simplifies thermal management in dense layouts.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD31C	V_CEO = 100 V, I_C = 3 A, f_T = 3 MHz, TO-220 package	Lower voltage rating limits use to ≤100 V DC systems; higher I_C suits higher-current but lower-voltage motor drives.	Select MJD31C only when V_CEO margin is sufficient and TO-220 mounting is preferred over TO-126 footprint.
BU508A	V_CEO = 1500 V, I_C = 8 A, t_F = 1.5 µs, TO-3P package	Higher voltage/current but slower switching and larger package; suited for 400–600 V line-powered SMPS with lower frequency (<50 kHz).	Choose BU508A when system requires >600 V standoff or >3 A peak current, accepting larger size and reduced efficiency at high frequency.

Compared with FJE3303TU, MJD31C offers higher current but insufficient voltage headroom for 310 V bus applications, while BU508A provides greater voltage margin and power handling at the cost of switching speed and board space-making FJE3303TU optimal for compact, medium-power, high-frequency ballast and SMPS designs.

Availability

FJE3303TU is available at Aetrix Electronics and suitable for electronic ballast control, switching regulator output stages, and industrial inductive load switching requiring stable component supply and long-term manufacturability.

Supply support for FJE3303TU 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

Fairchild Semiconductor was a U.S.-based designer and manufacturer of analog and discrete semiconductors, acquired by ON Semiconductor in 2016; known for PowerTrench®, FRFET™, and high-reliability power devices.

The FJE3303TU belongs to Fairchild's high-voltage bipolar transistor family engineered specifically for energy-efficient lighting and offline power conversion, emphasizing rugged SOA, fast switching, and thermal robustness in TO-126 packaging.

FAQ

What is the maximum continuous collector current rating for the FJE3303TU?

The FJE3303TU has a maximum continuous collector current (I_C) rating of 1.5 A at case temperature T_C = 25°C. This rating decreases with rising case temperature per the derating curve in Figure 9 of the datasheet. At T_C = 100°C, the usable I_C drops to approximately 0.75 A. Designers must ensure heatsinking maintains T_C within limits to sustain the full 1.5 A rating in the FJE3303TU.

Does the FJE3303TU have a built-in base-emitter resistor?

No, the FJE3303TU is a standard three-terminal NPN bipolar transistor without any integrated base-emitter resistor. It requires external base drive circuitry-including a series base resistor-to establish proper I_B for desired I_C and to prevent thermal runaway. The datasheet specifies base current requirements (e.g., I_B = 0.25 A for I_C = 1.0 A), confirming the need for discrete bias network design in the FJE3303TU application.

What is the safe operating area (SOA) limitation for the FJE3303TU at 100 V V_CE?

At V_CE = 100 V, the forward-biased SOA (Figure 7) limits the FJE3303TU to approximately 2.5 A for 10 ms pulses and 1.2 A for DC operation. These boundaries assume T_C = 25°C and no second-breakdown effects. For reliable design, engineers must stay left-of and below the SOA curve in the FJE3303TU datasheet, especially under inductive switching conditions where voltage overshoot and current tailing combine to stress the device.

Can the FJE3303TU replace the FJE3303 in existing designs?

Yes, the FJE3303TU is a direct replacement for the FJE3303, sharing identical electrical specifications, pinout (TO-126, pin 1 = emitter, pin 2 = collector, pin 3 = base), thermal characteristics, and mechanical dimensions. The "TU" suffix denotes tape-and-reel packaging for automated assembly, whereas the base part number may indicate bulk or tube packaging-but all parametric and functional data for the FJE3303TU match those published for the FJE3303 in Rev. B datasheet.

What is the typical base-emitter saturation voltage for the FJE3303TU at I_C = 1.0 A?

The typical base-emitter saturation voltage (V_BE(sat)) for the FJE3303TU is 1.2 V when I_C = 1.0 A and I_B = 0.25 A, per the Electrical Characteristics table. This value increases slightly at higher temperatures and remains within 1.0–1.2 V across the specified operating range. Accurate V_BE(sat) modeling is essential for calculating base drive power loss and ensuring sufficient I_B in the FJE3303TU circuit.

FJE3303TU Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 1.5 A

Voltage - Collector Emitter Breakdown (Max):: 400 V

Vce Saturation (Max) @ Ib, Ic:: 3V @ 500mA, 1.5A

Current - Collector Cutoff (Max):: 10µA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 8 @ 500mA, 2V

Power - Max:: 20 W

Frequency - Transition:: 4MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-126-3

FJE3303TU FAQ

1.How can I place an order for FJE3303TU through Aetrix?

Please submit a Request for Quotation (RFQ) for FJE3303TU 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 FJE3303TU reliable?

The price and inventory of FJE3303TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for FJE3303TU is usually 5 days.

3.What payment methods are accepted for FJE3303TU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for FJE3303TU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for FJE3303TU?

FJE3303TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your FJE3303TU 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 FJE3303TU?

For technical support, including FJE3303TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your FJE3303TU requirements.

6.How does Aetrix verify that FJE3303TU is sourced from the original manufacturer or authorized distributors?

All FJE3303TU 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 FJE3303TU meets industry standards.

7.What is the process for return or replacement of FJE3303TU?

All FJE3303TU units undergo pre-shipment inspection (PSI). If there is an issue with FJE3303TU, 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 FJE3303TU part is unused and in its original packaging.

Return procedure for FJE3303TU:

1.Submit a request within 90 days.

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

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