BU931T - 15A, 400V NPN Power Darlington Transistor | STMicroelectronics
Teilenummer: BU931T ✓ Aktiv| Menge | Stückpreis | Gesamt |
|---|---|---|
| 1 | $1.25 | $1,25 |
| 10 | $1.1 | $11,00 |
| 100 | $0.95 | $95,00 |
| 500 | $0.85 | $425,00 |
| 1.000 | $0.75 | $750,00 |
BU931T Übersicht
A Darlington transistor is a compound structure consisting of two bipolar junction transistors (BJTs) connected in a Darlington pair configuration, where the emitter of the first transistor drives the base of the second. This configuration provides extremely high current gain, typically in the range of 1000 to 10000, compared to a single BJT. Darlington transistors are widely used in high-current switching applications where a low base current is required to control a large collector current. They are part of the broader family of power transistors, which also includes MOSFETs and IGBTs, and are essential components in power electronics for amplification and switching.
Key features of the BU931T include a collector-emitter saturation voltage (VCE(sat)) of 2.0V maximum at IC=10A, ensuring low power loss during conduction. The device also offers a fast switching speed with a fall time of 1.5 microseconds, making it suitable for high-frequency applications up to 10 kHz. The integrated base-emitter resistor and base-emitter diode enhance reliability by preventing spurious turn-on due to leakage currents. The TO-220 package is lead-free and RoHS compliant, meeting modern environmental standards.
Technically, the BU931T utilizes a triple-diffused planar process, providing robust avalanche energy handling and a wide safe operating area (SOA). The device can withstand a collector-emitter breakdown voltage (BVCEO) of 400V and a collector-base voltage (VCBO) of 500V, ensuring high voltage robustness. The thermal resistance from junction to case (RthJC) is 1.0°C/W, allowing efficient heat transfer to an external heatsink. The operating junction temperature range is -65°C to +150°C, making it suitable for harsh environments.
Typical applications include motor control circuits, switching power supplies, automotive ignition systems, and solenoid drivers. In motor control, the BU931T can switch DC motors up to 15A, providing reliable on/off control. In automotive ignition, its high voltage and current ratings ensure dependable performance in demanding conditions. The device is also used in welding equipment and battery chargers where high current switching is required.
When designing with the BU931T, ensure adequate base drive current to achieve low saturation voltage. A base current of at least 1/250 of the collector current is recommended. Additionally, use a suitable heatsink to maintain junction temperature below 150°C, especially at high current levels. Proper snubber circuits may be required to protect against inductive load transients.
Drop-in-Alternativen für BU931T – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Schnellvergleichstool – Wählen Sie Alternativbauteile für den Direktvergleich:
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MJ10015
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MJE13009
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2N6547
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BU931T Grenzwerte & elektrische Eigenschaften
| Transistortyp | NPN Darlington |
| Kollektor-Emitter-Spannung (Vceo) | 400 V |
| Kollektor-Basis-Spannung (Vcbo) | 500 V |
| Emitter-Basis-Spannung (Vebo) | 5 V |
| Continuous Collector Current (IC) | 15 A |
| Peak Collector Current (ICM) | 30 A |
| Power Dissipation (PC) | 125 W |
| DC Current Gain (hFE) | 500 min at IC=10A, VCE=5V |
| Kollektor-Emitter-Sättigungsspannung (Vce(sat)) | 2.0 V max at IC=10A, IB=40mA |
| Base-Emitter Saturation Voltage (VBE(sat)) | 2.5 V max at IC=10A, IB=40mA |
| Fall Time (tf) | 1.5 µs |
| Storage Time (ts) | 2.5 µs |
| Thermal Resistance (RthJC) | 1.0 °C/W |
| Betriebs-Sperrschichttemperatur | -65°C to +150°C |
| Gehäuse | TO-220 |
| Montageart | Through Hole |
| RoHS-Status | Compliant |
BU931T Pin-Konfiguration
| Pin 1 | Base — Base terminal for controlling the transistor |
| Pin 2 | Collector — Collector terminal, connected to the load |
| Pin 3 | Emitter — Emitter terminal, connected to ground |
Sicherer Arbeitsbereich (DC)
Typische Anwendungen
BU931T ist geeignet für 6 Anwendungs: Motor Control, Switching Power Supplies, Automotive Ignition Systems, Solenoid Drivers, Battery Chargers, Welding Equipment.
Motor Control
The BU931T is ideal for motor control applications due to its high current rating (15A) and voltage rating (400V). It can switch DC motors directly, providing reliable on/off control. In PWM motor control, the BU931T's fast switching speed (fall time 1.5µs) allows efficient operation at frequencies up to 10 kHz. The low saturation voltage (2.0V) minimizes power loss, improving overall system efficiency. For inductive loads, a flyback diode is recommended to protect the transistor from voltage spikes. The TO-220 package allows easy mounting on a heatsink for thermal management. Compared to MOSFETs, the Darlington transistor offers higher current gain, simplifying the drive circuit. However, for high-frequency PWM above 10 kHz, a MOSFET may be more suitable due to lower switching losses. The BU931T is commonly used in industrial motor control panels, robotics, and automotive applications.
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Switching Power Supplies
In switching power supplies, the BU931T is used as a high-voltage switch in the primary side of flyback or forward converters. Its 400V VCEO rating allows it to handle rectified 240V AC mains (approximately 340V DC). The high current gain (hFE 500) enables direct driving from PWM controller ICs without additional driver stages. The fast switching speed ensures efficient operation at typical switching frequencies of 50-100 kHz, though the BU931T is more suited for lower frequencies due to its storage time. The low saturation voltage reduces conduction losses, improving efficiency. Thermal management is critical, as power dissipation can be significant at high currents. A heatsink with adequate thermal resistance is required. The BU931T is often used in offline power supplies for consumer electronics, industrial equipment, and battery chargers. For higher efficiency, a MOSFET or IGBT may be preferred, but the BU931T offers a cost-effective solution for moderate power levels.
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Automotive Ignition Systems
The BU931T is well-suited for automotive ignition systems, where it switches the ignition coil to generate high-voltage sparks. Its 400V VCEO rating is sufficient to handle the back-EMF from the ignition coil, which can exceed 300V. The high current rating (15A) allows it to handle the coil's primary current, typically 5-10A. The fast switching speed ensures precise timing of the spark, improving engine performance and fuel efficiency. The device's ruggedness and wide operating temperature range (-65°C to +150°C) make it suitable for the harsh automotive environment. The TO-220 package can be mounted on a heatsink or directly on the engine block for thermal management. The integrated base-emitter resistor and diode provide protection against spurious turn-on due to electrical noise. The BU931T is used in both conventional and electronic ignition systems, offering reliable performance in demanding conditions.
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Solenoid Drivers
The BU931T is an excellent choice for driving solenoids in industrial automation, vending machines, and locking systems. Solenoids require a high inrush current to actuate, which the BU931T can provide with its 15A continuous and 30A peak current ratings. The high voltage rating (400V) ensures compatibility with various supply voltages, including 24V, 48V, and 120V systems. The low saturation voltage minimizes power dissipation during the hold phase, reducing heat generation. The fast switching speed allows rapid actuation and release, improving system response time. For inductive loads, a flyback diode is essential to clamp voltage spikes. The BU931T can be driven directly from a microcontroller via a base resistor, thanks to its high current gain. The TO-220 package is easy to mount on a PCB or heatsink. This application is common in factory automation, where reliability and long life are critical.
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Battery Chargers
The BU931T is used in battery charger circuits for switching the charging current. Its high current rating (15A) allows it to handle charging currents for lead-acid, NiMH, and Li-ion batteries. The 400V VCEO rating makes it suitable for chargers connected to AC mains, where the rectified voltage can be high. The low saturation voltage reduces power loss, improving charging efficiency. The fast switching speed enables PWM-based charging algorithms for precise current control. The device's ruggedness ensures reliable operation in harsh environments. Thermal management is important, as high charging currents can cause significant power dissipation. A heatsink is recommended. The BU931T is commonly used in automotive battery chargers, industrial charging stations, and portable chargers. For higher efficiency, a synchronous rectifier MOSFET may be used, but the BU931T offers a simple and cost-effective solution.
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Welding Equipment
The BU931T is used in welding equipment for switching the high current required for arc welding. Its 15A continuous and 30A peak current ratings can handle the welding current, which can be several hundred amps when using multiple transistors in parallel. The 400V VCEO rating ensures compatibility with the high voltages present in welding circuits. The low saturation voltage minimizes power loss, improving efficiency and reducing heat generation. The fast switching speed enables precise control of the welding arc. The device's ruggedness and wide operating temperature range make it suitable for the demanding welding environment. The TO-220 package can be mounted on a heatsink for thermal management. The BU931T is used in both inverter-based and traditional transformer-based welding machines. For high-frequency inverter welders, an IGBT may be preferred, but the BU931T offers a cost-effective solution for lower-frequency applications.
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Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für BU931T – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | BU931 | TIP140 | MJ10015 | MJE13009 | 2N6547 |
|---|---|---|---|---|---|---|
| Package | TO-220 | TO-220 | TO-220 | TO-220 | TO-220 | TO-220 |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | ON Semiconductor | ON Semiconductor | STMicroelectronics |
| Collector-Emitter Voltage (VCEO) | 400 V | 400 V | 400 V | 400 V | 400 V | 400 V |
| Continuous Collector Current (IC) | 15 A | 15 A | 15 A | 15 A | 12 A | 10 A |
| Power Dissipation (PC) | 125 W | 125 W | 125 W | 125 W | 100 W | 100 W |
| DC Current Gain (hFE) | 500 min at 10A | 500 min at 10A | 500 min at 10A | 500 min at 10A | 500 min at 8A | 500 min at 5A |
| Collector-Emitter Saturation Voltage (VCE(sat)) | 2.0 V max at 10A | 2.0 V max at 10A | 2.0 V max at 10A | 2.0 V max at 10A | 2.0 V max at 8A | 2.0 V max at 5A |
| Fall Time (tf) | 1.5 µs | 1.5 µs | 1.5 µs | 1.5 µs | 1.0 µs | 1.5 µs |
Wichtigste Unterscheidungsmerkmale
- High current gain (hFE 500 min) simplifies drive circuitry (vs. MJE13009)
- Higher power dissipation (125W) allows more robust designs (vs. 2N6547)
- Same-brand drop-in compatibility with BU931 (vs. BU931)
Designhinweise
The BU931T dissipates up to 125W, requiring a heatsink with a thermal resistance of less than 1.0°C/W to keep the junction temperature below 150°C. For example, at 50W dissipation, the junction-to-case temperature rise is 50°C, so the case must be kept below 100°C. Use thermal compound and a proper mounting torque to ensure good thermal contact.
When driving inductive loads such as motors or solenoids, always place a flyback diode (e.g., 1N4007) across the load to clamp voltage spikes. Without it, the collector-emitter voltage can exceed the 400V rating, damaging the transistor. Also, ensure the base drive current is sufficient (at least IC/250) to achieve low saturation voltage.
For TO-220 packages, ensure the leads are properly inserted into the PCB and soldered with adequate solder fillets. The tab is connected to the collector, so if it is mounted on a heatsink, ensure electrical isolation if the heatsink is grounded. Use a mica washer and insulating bushing if needed.
Compliance-Informationen
RoHS compliant per STMicroelectronics datasheet. Not AEC-Q100 qualified as it is a discrete transistor, not an IC.
