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onsemi BU407TU
- Part No.:
- BU407TU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-220-3
- Datasheet:
-
BU407TU.pdf
- Description:
- TRANS NPN 150V 7A TO-220-3
- Quantity:
- Payment:
- Shipping:
Inventory:9,503
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Product details
Overview
BU407TU from ON Semiconductor is an NPN epitaxial silicon power transistor designed for high-voltage switching applications, featuring a 330 V collector-base voltage (VCBO), 150 V collector-emitter voltage (VCEO), 7 A DC collector current (IC), 60 W collector dissipation at TC=25°C, and TO-220 package. It is commonly used in horizontal deflection output stages of CRT displays.
For engineers reviewing the BU407TU datasheet, pinout, applications, or equivalent options, key selection criteria include safe operating area (SOA) compliance at high VCE, low saturation voltage under pulsed 5 A load, turn-off time performance, thermal derating behavior, and compatibility with flyback snubber networks in line-output circuits.
Technical Context
The BU407TU operates as a single NPN bipolar junction transistor optimized for high-voltage, medium-current switching-distinct from MOSFETs or IGBTs due to its current-controlled base drive and inherent gain-dependent saturation behavior. Its fT of 10 MHz supports stable operation in horizontal deflection frequencies up to ~16 kHz with adequate phase margin.
It exhibits defined SOA boundaries across pulse widths (1 ms to 100 ms), with dissipation-limited and current-limited regions clearly specified. The device's tOFF of 0.75 µs (at IC = 5 A, IB = 0.5 A) enables fast transition out of saturation, reducing switching losses in resonant line-output stages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCBO | 330 V - Supports operation with peak flyback voltages exceeding 300 V in CRT horizontal deflection circuits. |
| VCEO | 150 V - Defines maximum sustainable collector-emitter voltage under active switching with base bias applied. |
| IC (DC) | 7 A - Continuous collector current rating usable in thermally managed designs with heatsink and forced airflow. |
| PC (TC=25°C) | 60 W - Maximum power dissipation at case temperature of 25°C; derates linearly above 25°C per published curve. |
| fT | 10 MHz - Current-gain bandwidth product enabling stable small-signal amplification and predictable switching edge control. |
| tOFF | 0.75 µs - Measured turn-off delay + fall time at IC = 5 A, IB = 0.5 A; critical for minimizing overlap loss in quasi-resonant flyback drivers. |
| VCE(sat) | 1 V - Collector-emitter saturation voltage at IC = 5 A, IB = 0.5 A; determines conduction loss during on-state in line-output stage. |
| TJ max | 150 °C - Maximum allowable junction temperature; sets thermal design margin for reliability under sustained load. |
Pinout & Package
BU407TU is housed in a through-hole TO-220 package with insulated tab, standard pin configuration (1: Base, 2: Collector, 3: Emitter), and mechanical dimensions compliant with JEDEC TO-220AB outline.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Base) | Control input terminal | Receives forward base current to drive transistor into saturation; requires external current-limiting resistor or driver stage. |
| 2 (Collector) | High-voltage output node | Connected to flyback transformer primary and horizontal output transformer; carries full line-frequency switched current and voltage spikes. |
| 3 (Emitter) | Current return path | Common emitter connection referenced to ground or damper network; carries full collector current with minimal voltage drop. |
Key Features
| Feature | Design Value |
|---|---|
| High VCBO rating | 330 V enables robust operation in CRT horizontal deflection circuits with high-energy flyback transients. |
| Low VCE(sat) | 1 V at 5 A/0.5 A reduces conduction loss and thermal stress during active switching periods. |
| Fast tOFF | 0.75 µs ensures clean turn-off in 15.734 kHz line-scan applications, minimizing overlap loss. |
| Defined SOA | Published safe operating area curves support reliable design across pulse widths from 1 ms to 100 ms. |
| TO-220 mechanical standard | Industry-standard footprint allows direct replacement in legacy CRT TV and monitor repair boards. |
Applications
| Horizontal Deflection Output Stage | Switched-Mode Power Supply (Flyback) |
|---|---|
Use Scenario: Driving the primary winding of a horizontal output transformer in CRT television and monitor systems. IC Role / Device Role / Timing Role: High-voltage NPN switch synchronized to line-scan frequency (~15.734 kHz), handling repetitive 5–7 A pulses with 300+ V flyback peaks. Use Value: BU407TU's 330 V VCBO and SOA-rated 5 A pulse capability ensure reliable operation without secondary breakdown under transient overvoltage conditions. | Use Scenario: Primary-side switching element in low-to-medium power offline flyback converters for auxiliary supplies. IC Role / Device Role / Timing Role: Main power switch controlling energy transfer from AC input to isolated DC output, operating at fixed or variable frequency below 100 kHz. Use Value: BU407TU's 150 V VCEO and 60 W dissipation allow stable operation at 100–120 VDC bus with proper snubbing and heatsinking. |
| Electronic Ballast Driver | Induction Heater Half-Bridge |
Use Scenario: Switching element in magnetic or electronic fluorescent lamp ballasts requiring high-voltage ignition pulses. IC Role / Device Role / Timing Role: High-voltage switch generating resonant start-up voltage (>600 V) and sustaining lamp current at 20–60 kHz. Use Value: BU407TU's 10 MHz fT and fast tOFF support stable oscillation in parallel-resonant LC ballast topologies. | Use Scenario: Low-side switch in asymmetrical half-bridge configurations for low-kW induction heating coils. IC Role / Device Role / Timing Role: Medium-speed, high-current switch delivering 5–7 A at 20–50 kHz with controlled dv/dt to minimize EMI. Use Value: BU407TU's low VCE(sat) and SOA compliance reduce conduction and switching losses while maintaining thermal stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar NPN high-voltage switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BU406 | Lower VCBO (300 V) and VCEO (120 V); same TO-220 package and pinout. | Suitable only for lower-voltage flyback or deflection circuits where peak voltage remains <280 V. | Select BU406 when system flyback voltage is confirmed ≤280 V and thermal margin allows reduced voltage headroom. |
| 2SC5200 | Higher IC (15 A), higher PC (150 W), but lower VCBO (230 V); TO-3P package, different pinout. | Better for high-current audio amplifier output stages, not recommended for >250 V deflection use. | Choose 2SC5200 only if current demand exceeds 7 A and voltage stress stays below 200 V; requires PCB layout change. |
Compared with BU406 and 2SC5200, the BU407TU offers optimal balance of 330 V voltage capability, 7 A current handling, and TO-220 compatibility for CRT horizontal deflection-neither under-rated like BU406 nor over-specified and mechanically incompatible like 2SC5200.
Availability
BU407TU is available at Aetrix Electronics and suitable for CRT display repair, flyback converter design, electronic ballast development, and induction heater prototyping requiring stable component supply and long-term industrial availability.
Supply support for BU407TU 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
ON Semiconductor is a global semiconductor manufacturer specializing in power management, analog, sensor, and discrete devices for automotive, industrial, and consumer applications.
The BU407TU belongs to ON Semiconductor's legacy high-voltage bipolar transistor product line, originally developed by Fairchild for CRT horizontal deflection and high-reliability switching applications.
FAQ
What is the maximum collector-emitter voltage rating for BU407TU?
The BU407TU has a maximum collector-emitter voltage (VCEO) rating of 150 V at TC = 25°C. This rating defines the highest DC voltage the device can sustain between collector and emitter with base open, and must be derated at elevated case temperatures per the published power derating curve. Exceeding this limit risks secondary breakdown, especially under high-current conditions.
Does BU407TU have a built-in base-emitter resistor?
No, the BU407TU is a standard NPN bipolar transistor without any integrated base-emitter resistor. It requires external base drive circuitry-including a current-limiting resistor or active driver-to establish proper forward bias and avoid thermal runaway. This distinguishes it from digital transistors (e.g., MMBT series) that integrate resistors.
What is the typical saturation voltage of BU407TU under rated conditions?
The typical collector-emitter saturation voltage (VCE(sat)) of BU407TU is 1 V when tested at IC = 5 A and IB = 0.5 A. This value reflects conduction loss during the on-state and directly impacts thermal design-lower VCE(sat) reduces power dissipation and improves efficiency in high-duty-cycle switching applications like CRT horizontal deflection.
Can BU407TU replace BU407 in existing designs?
Yes, BU407TU is functionally identical to BU407 and shares the same electrical specifications, TO-220 package, and pinout. The "TU" suffix denotes tape-and-reel packaging for automated assembly, whereas BU407 typically refers to tube-packaged units. Electrical performance, thermal characteristics, and reliability are fully aligned between both variants.
Is BU407TU suitable for Class D audio amplifier output stages?
BU407TU is not recommended for Class D audio amplifier output stages due to its relatively slow switching speed (tOFF = 0.75 µs) and bipolar architecture, which lacks the gate-drive simplicity and high-frequency efficiency of MOSFETs. While it can handle the current, its switching losses and limited fT make it unsuitable for >100 kHz PWM audio applications where low THD and high efficiency are required.
BU407TU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 7 A
- Voltage - Collector Emitter Breakdown (Max):
- 150 V
- Vce Saturation (Max) @ Ib, Ic:
- 1V @ 500mA, 5A
- Current - Collector Cutoff (Max):
- 5mA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- -
- Power - Max:
- 60 W
- Frequency - Transition:
- 10MHz
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-3
BU407TU FAQ
1.How can I place an order for BU407TU through Aetrix?
Please submit a Request for Quotation (RFQ) for BU407TU 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 BU407TU reliable?
The price and inventory of BU407TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BU407TU is usually 5 days.
3.What payment methods are accepted for BU407TU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BU407TU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BU407TU?
BU407TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BU407TU 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 BU407TU?
For technical support, including BU407TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BU407TU requirements.
6.How does Aetrix verify that BU407TU is sourced from the original manufacturer or authorized distributors?
All BU407TU 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 BU407TU meets industry standards.
7.What is the process for return or replacement of BU407TU?
All BU407TU units undergo pre-shipment inspection (PSI). If there is an issue with BU407TU, 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 BU407TU part is unused and in its original packaging.
Return procedure for BU407TU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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