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onsemi BUT11AFTU
- Part No.:
- BUT11AFTU
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-220-3 Full Pack
- Datasheet:
-
BUT11AFTU.pdf
- Description:
- TRANS NPN 450V 5A TO-220F-3
- Quantity:
- Payment:
- Shipping:
Inventory:337
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Product details
Overview
BUT11AFTU from ON Semiconductor (formerly Fairchild) is a high-voltage NPN silicon power transistor designed for switching applications in industrial and consumer power supplies, motor controls, and snubberless triac drivers. It features 1000 V collector-base voltage (VCBO), 450 V collector-emitter voltage (VCEO), 5 A DC collector current, 40 W collector dissipation at TC = 25°C, and TO-220F package with insulated flange.
For engineers reviewing the BUT11AFTU datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage blocking capability (VCBO = 1000 V), low saturation voltage (VCE(sat) = 1.5 V @ IC = 2.5 A, IB = 0.5 A), fast switching performance (tON = 1 µs, tF = 0.8 µs), and thermal resistance (RθjC = 3.125 °C/W) for reliable high-power operation.
Technical Context
This device operates as a single NPN bipolar junction transistor optimized for high-voltage, medium-current switching. Its rugged safe operating area (SOA) supports repetitive pulse loads up to 10 A (ICP), with sustaining voltage VCEO(sus) = 450 V under open-base conditions - critical for snubberless AC switch control.
The TO-220F package provides electrical isolation between the collector-connected flange and mounting surface, enabling direct heatsink attachment without insulating hardware. Thermal design relies on RθjC = 3.125 °C/W and maximum junction temperature of 150°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCBO | 1000 V - enables use in 600–800 V DC bus systems with margin against transients |
| VCEO | 450 V - supports 230 VAC line-switching applications with full safety margin |
| IC (DC) | 5 A - delivers continuous load current for relay drivers and small motor controls |
| VCE(sat) | 1.5 V @ IC = 2.5 A, IB = 0.5 A - limits conduction loss to ≤3.75 W at rated current |
| tON / tF | 1 µs / 0.8 µs - ensures efficient switching above 100 kHz in resonant converters |
| RθjC | 3.125 °C/W - allows 40 W dissipation with ≤125°C case-to-ambient rise using standard heatsinks |
| hFE (min) | 10 @ IC = 2.5 A - confirms sufficient DC current gain for base-driven switching without excessive drive power |
Pinout & Package
Package: TO-220F (insulated flange, 3-lead, vertical mounting). Flange is electrically connected to collector; electrically isolated from heatsink mounting surface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Base) | Control input terminal | Receives base current (IB ≤ 2 A DC) to saturate or cut off the transistor; requires external current-limiting resistor |
| 2 (Collector) | Main power output terminal | Connected to high-voltage rail or inductive load; flange is internally tied to this pin and must be isolated from chassis ground |
| 3 (Emitter) | Power return path | Serves as common reference for load and base drive; carries full load current and must be routed with low-inductance layout |
Key Features
| Feature | Design Value |
|---|---|
| High VCBO rating | 1000 V - supports operation in 800 V DC intermediate bus architectures with 20% margin |
| Snubberless triac driving capability | VCEO(sus) = 450 V @ IC = 100 mA, IB = 0 - eliminates need for external snubber networks in AC phase-control circuits |
| Fast switching with low storage time | tSTG = 4 µs - reduces switching losses and improves efficiency in high-frequency inverters |
| Insulated flange package | TO-220F - enables direct mechanical mounting to grounded heatsinks without thermal pad or mica insulator |
| Rugged SOA | Rated for repetitive pulsed operation up to 10 A (ICP) - withstands surge currents in motor startup and capacitor charging |
Applications
| Industrial Motor Starters | AC Line Voltage Switching |
|---|---|
Use Scenario: Controlling 1/4–1 HP induction motors in HVAC blowers and pump controllers using phase-angle or burst-fire AC switching. IC Role / Device Role / Timing Role: High-voltage NPN switch driving gate of main triac or directly switching neutral-side load in snubberless configuration. Use Value: Eliminates external snubber components due to VCEO(sus) = 450 V and robust reverse-biased SOA, reducing BOM count and board space. | Use Scenario: Solid-state relays and programmable logic controller (PLC) output modules switching 230 VAC/5 A resistive or inductive loads. IC Role / Device Role / Timing Role: Main power switching element handling full load current with galvanic isolation provided by optocoupler-driven base circuit. Use Value: 450 V VCEO and 5 A IC rating ensure reliable operation across global AC mains voltages with thermal margin via TO-220F package. |
| Switched-Mode Power Supply (SMPS) Snubber | High-Voltage DC-DC Converter Stage |
Use Scenario: Clamping voltage spikes in flyback and forward converter primary switches during turn-off. IC Role / Device Role / Timing Role: Transient voltage suppressor in active clamp or passive snubber network, triggered by auxiliary winding feedback. Use Value: 1000 V VCBO withstands reflected voltage peaks exceeding 800 V, preventing avalanche failure during overvoltage events. | Use Scenario: Primary-side switching in 400–600 V input DC-DC converters for telecom and industrial power systems. IC Role / Device Role / Timing Role: Main switching transistor in hard-switched or quasi-resonant topologies operating at ≤100 kHz. Use Value: Low VCE(sat) = 1.5 V and fast tF = 0.8 µs minimize conduction and switching losses, improving overall converter efficiency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage NPN switching transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BU508AF | VCBO = 1500 V, VCEO = 700 V, IC = 8 A, TO-220F package | Higher voltage rating suits 1000 V DC bus systems; higher current supports larger motor drives | Select BU508AF when system transient voltage exceeds 1000 V or continuous load current exceeds 5 A |
| ST13007 | VCBO = 800 V, VCEO = 400 V, IC = 8 A, TO-220 package (non-insulated flange) | Lower voltage rating but higher current; requires insulating hardware for heatsink mounting | Select ST13007 only in lower-voltage (<400 V) applications where cost and current capacity outweigh insulation needs |
Compared with BUT11AFTU, BU508AF offers greater voltage headroom for harsher transients but consumes more base drive; ST13007 trades voltage margin for higher current and lower cost but mandates external isolation - making BUT11AFTU the optimal balance of 1000 V VCBO, 450 V VCEO, and integrated flange insulation for 230 VAC and 400 VDC systems.
Availability
BUT11AFTU is available at Aetrix Electronics and suitable for industrial motor starters, AC line voltage switching modules, and high-voltage DC-DC converter stages requiring stable component supply and long-term manufacturability.
Supply support for BUT11AFTU 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 (formerly Fairchild Semiconductor) is a global semiconductor supplier specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and cloud power markets.
The BUT11AFTU belongs to Fairchild's legacy high-voltage bipolar transistor family, engineered specifically for robust, snubberless AC switching and high-reliability industrial power control applications.
FAQ
What is the maximum allowable collector-emitter voltage for BUT11AFTU in continuous operation?
The BUT11AFTU has a maximum continuous collector-emitter voltage (VCEO) rating of 450 V at TC = 25°C. This value is validated under DC conditions with the base open; derating is required above 25°C case temperature per the power derating curve in the datasheet. Exceeding 450 V risks avalanche breakdown and permanent device failure.
Does BUT11AFTU require an insulating pad when mounted to a metal heatsink?
No - the BUT11AFTU uses a TO-220F package with an electrically insulated flange tied to the collector. This allows direct mechanical mounting to a grounded heatsink without thermal pads, mica insulators, or sil-pads. Electrical isolation is built-in, simplifying thermal design and reducing assembly steps.
What base current is needed to fully saturate BUT11AFTU at 5 A collector current?
To achieve full saturation at IC = 5 A, the BUT11AFTU requires IB ≥ 1 A (based on hFE(min) ≈ 5 at high current). However, the datasheet specifies VCE(sat) = 1.5 V at IC = 2.5 A / IB = 0.5 A (hFE = 5), so for 5 A, IB ≈ 1.0–1.2 A is recommended. Ensure base drive circuit can source ≥1.2 A peak without voltage droop.
Can BUT11AFTU replace BUT11F in existing designs?
Yes - BUT11AFTU is the insulated-flange variant of BUT11F with identical electrical specifications (VCBO = 1000 V, VCEO = 450 V, etc.) and same pinout. The "A" suffix denotes TO-220F packaging; it is a drop-in replacement where flange isolation is required or preferred. No PCB changes are needed.
What is the safe operating area (SOA) limitation for BUT11AFTU at 100°C case temperature?
At TC = 100°C, the BUT11AFTU's SOA is limited by both second breakdown and thermal constraints. From the datasheet's Figure 5, the maximum sustainable collector current drops to ~2.2 A at VCE = 400 V. For reliable operation, limit simultaneous VCE and IC to points within the derated SOA boundary - especially critical during inductive switching transitions.
BUT11AFTU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-3 Full Pack
- Packaging:
- Tube
- Product Status:
- Last Time Buy
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 5 A
- Voltage - Collector Emitter Breakdown (Max):
- 450 V
- Vce Saturation (Max) @ Ib, Ic:
- 1.5V @ 500mA, 2.5A
- Current - Collector Cutoff (Max):
- 1mA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- -
- Power - Max:
- 40 W
- Frequency - Transition:
- -
- Operating Temperature:
- 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220F-3
BUT11AFTU FAQ
1.How can I place an order for BUT11AFTU through Aetrix?
Please submit a Request for Quotation (RFQ) for BUT11AFTU 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 BUT11AFTU reliable?
The price and inventory of BUT11AFTU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUT11AFTU is usually 5 days.
3.What payment methods are accepted for BUT11AFTU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUT11AFTU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BUT11AFTU?
BUT11AFTU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BUT11AFTU 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 BUT11AFTU?
For technical support, including BUT11AFTU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUT11AFTU requirements.
6.How does Aetrix verify that BUT11AFTU is sourced from the original manufacturer or authorized distributors?
All BUT11AFTU 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 BUT11AFTU meets industry standards.
7.What is the process for return or replacement of BUT11AFTU?
All BUT11AFTU units undergo pre-shipment inspection (PSI). If there is an issue with BUT11AFTU, 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 BUT11AFTU part is unused and in its original packaging.
Return procedure for BUT11AFTU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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