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onsemi BUD42DT4G
- Part No.:
- BUD42DT4G
- Manufacturer:
- onsemi
- Category:
- Single Bipolar Transistors
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
BUD42DT4G.pdf
- Description:
- TRANS NPN 350V 4A DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:7,775
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Product details
Overview
BUD42DT4G from onsemi is a high-speed, high-gain NPN bipolar transistor with integrated antisaturation network and transient voltage suppression capability, rated for 650 VCEO, 4 A continuous collector current, and 25 W power dissipation in DPAK (Case 369C) package - designed for electronic ballast circuits in fluorescent lamp control systems.
For engineers reviewing the BUD42DT4G datasheet, pinout, applications, or equivalent options, key selection criteria include its 350 VCEO(sus) sustaining voltage under inductive switching, fast turn-off time (4.6–6.55 µs), built-in freewheeling diode, flat DC current gain across operating range, and RoHS-compliant Pb-free DPAK packaging.
Technical Context
The BUD42DT4G integrates an internal antisaturation network to minimize storage time and improve switching efficiency in high-voltage inductive loads. Its dual-collector configuration supports robust clamping during turn-off transients, while the monolithic freewheeling diode enables self-contained flyback energy handling without external components.
It operates with tight parameter spreads enabled by "6 Sigma" process control, delivering consistent hFE of 8–13 at IC = 1 A and VCE = 2 V, and dynamic saturation voltage as low as 0.35 V at 1 A/200 mA drive after 3 µs - critical for minimizing conduction loss in high-frequency ballast drivers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCEO(sus) | 350 V - Sustaining voltage under 25 mH inductive load; defines safe operating margin during lamp ignition surges. |
| IC Continuous | 4.0 A - Maximum steady-state collector current; supports >30 W lamp drive with thermal headroom at TC = 25°C. |
| PD | 25 W - Total device dissipation at TC = 25°C; enables compact heatsink design with RJC = 5.0 °C/W. |
| hFE @ IC = 1 A | 8–13 - Flat DC current gain ensures stable base drive requirements across temperature and production lots. |
| Toff | 4.6–6.55 µs - Turn-off time under 300 V, 1.2 A resistive load; enables operation up to ~50 kHz in ballast topologies. |
| VCE(sat) @ IC = 2 A | 0.2–1.0 V - Low saturation voltage reduces conduction losses and improves system efficiency at full load. |
| VEC | 0.9–1.5 V - Forward diode voltage at 1.0 A; confirms integrated freewheeling path with minimal forward drop. |
Pinout & Package
DPAK (Case 369C) surface-mount package with 4-terminal configuration: thermally enhanced copper tab (Collector), standard leadframe layout, and UL 94 V-0 compliant epoxy molding compound.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Base | Control input for transistor switching; requires 0.2–0.5 A peak base drive for full saturation at 2–4 A collector current. |
| 2 | Collector | Main high-voltage current path; electrically connected to exposed metal tab for thermal and electrical grounding. |
| 3 | Emitter | Reference node for base-emitter junction; carries full load current and serves as return path for freewheeling diode. |
| 4 | Collector | Second collector terminal tied internally to Pin 2; provides redundant connection for improved current sharing and thermal distribution. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated freewheeling diode | Eliminates need for external flyback diode in ballast half-bridge outputs, reducing BOM count and PCB area. |
| Antisaturation network | Reduces storage time and improves switching speed without requiring external Baker clamp circuitry. |
| 650 VVCBO rating | Supports operation in 230 VAC mains-fed ballasts with margin against line transients and inductive kickback. |
| "6 Sigma" process control | Ensures tight lot-to-lot spread in hFE, VCE(sat), and toff - critical for consistent light output and EMI performance. |
| Pb-free, RoHS-compliant | Meets global environmental compliance requirements for lighting equipment and industrial electronics manufacturing. |
Applications
| Fluorescent Lamp Ballast | Electronic Ignition Circuit |
|---|---|
Use Scenario: High-frequency AC drive for T5/T8 fluorescent tubes in commercial lighting fixtures. IC Role / Device Role / Timing Role: Main switching transistor in half-bridge resonant inverter stage; handles 30–50 kHz square-wave switching with inductive load. Use Value: Integrated diode and antisaturation network reduce component count by two parts and improve reliability over discrete alternatives. |
Use Scenario: Ignition pulse generation for instant-start fluorescent lamps requiring >600 V peak voltage. IC Role / Device Role / Timing Role: High-voltage switch triggering series-resonant tank; sustains 350 VCEO(sus) during lamp strike phase. Use Value: 350 V sustaining voltage and 650 VVCBO provide margin against 1.5× mains overvoltage events during cold start. |
| Inductive Load Driver | Compact Power Converter |
Use Scenario: 24–48 VDC-powered magnetic ballast replacement modules for retrofit LED-tube compatibility. IC Role / Device Role / Timing Role: Primary switch in flyback or forward converter powering auxiliary control circuitry. Use Value: 25 W power rating and RJC = 5.0 °C/W enable direct mounting to metal housing without additional heatsink. |
Use Scenario: Space-constrained AC/DC adapters for office equipment requiring high-voltage isolation. IC Role / Device Role / Timing Role: High-side switch in primary-side regulation topology; operates with 300 VCC supply. Use Value: Fast toff (≤6.55 µs) and flat hFE support stable feedback loop response across input voltage and load variations. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage bipolar transistor applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MJD42T4G | Same DPAK package, but lower VCEO = 300 V and no integrated freewheeling diode. | Suitable for lower-voltage DC-DC converters; not recommended for 230 VAC ballasts due to insufficient surge margin. | Select only if system peak voltage remains ≤250 V and external diode integration is acceptable. |
| BUL49D | Higher VCEO = 1000 V, TO-220 package, no integrated diode, slower toff (~10 µs). | Better for universal-input offline SMPS; unsuitable for high-frequency ballast due to switching speed limitation. | Prefer when higher voltage margin is needed and board space allows through-hole mounting. |
Compared with MJD42T4G and BUL49D, the BUD42DT4G uniquely combines 350 VCEO(sus), integrated diode, and sub-7 µs turn-off in surface-mount DPAK - making it the only option optimized for compact, high-reliability fluorescent ballast designs.
Availability
BUD42DT4G is available at Aetrix Electronics and suitable for fluorescent lamp ballasts, electronic ignition circuits, and inductive load drivers requiring stable component supply, long-term manufacturability, and RoHS-compliant sourcing.
Supply support for BUD42DT4G 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 management, analog, sensors, and logic solutions for automotive, industrial, and consumer markets.
The BUD42DT4G belongs to onsemi's high-voltage bipolar transistor family engineered specifically for lighting control applications - emphasizing ruggedness under inductive switching, tight parameter distribution, and integrated protection features.
FAQ
What is the maximum safe operating voltage for BUD42DT4G in inductive switching applications?
The BUD42DT4G is rated for 350 VCEO(sus) with IC = 100 mA and L = 25 mH, meaning it can safely sustain 350 V during turn-off transients in fluorescent lamp ballasts. Exceeding this value risks secondary breakdown; design margin should maintain peak voltage ≤300 V for long-term reliability.
Does BUD42DT4G require an external freewheeling diode?
No - the BUD42DT4G integrates a monolithic freewheeling diode between emitter and collector (VEC = 0.9–1.5 V at 1.0 A), eliminating the need for an external diode in standard half-bridge ballast configurations. This reduces component count and improves layout compactness.
What is the thermal resistance from junction to case for BUD42DT4G?
The BUD42DT4G has a maximum thermal resistance of RJC = 5.0 °C/W, measured from junction to the exposed collector tab. This enables efficient heat transfer to a heatsink or metal chassis, supporting 25 W dissipation at TC = 25°C with appropriate thermal interface design.
How does the antisaturation network in BUD42DT4G improve switching performance?
The integrated antisaturation network actively limits base-collector forward bias during turn-on, reducing minority carrier storage time and enabling faster turn-off. This results in toff of 4.6–6.55 µs - significantly shorter than conventional bipolar transistors without such networks.
Is BUD42DT4G compatible with lead-free reflow soldering processes?
Yes - the BUD42DT4G is Pb-free and RoHS-compliant, qualified for standard lead-free reflow profiles with peak temperature up to 260°C (measured 1/8 inch from case for 5 seconds), matching IPC/JEDEC J-STD-020 requirements.
BUD42DT4G Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Transistor Type:
- NPN
- Current - Collector (Ic) (Max):
- 4 A
- Voltage - Collector Emitter Breakdown (Max):
- 350 V
- Vce Saturation (Max) @ Ib, Ic:
- 1V @ 500mA, 2A
- Current - Collector Cutoff (Max):
- 100µA
- DC Current Gain (hFE) (Min) @ Ic, Vce:
- 10 @ 2A, 5V
- Power - Max:
- 25 W
- Frequency - Transition:
- -
- Operating Temperature:
- -65°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
BUD42DT4G FAQ
1.How can I place an order for BUD42DT4G through Aetrix?
Please submit a Request for Quotation (RFQ) for BUD42DT4G 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 BUD42DT4G reliable?
The price and inventory of BUD42DT4G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUD42DT4G is usually 5 days.
3.What payment methods are accepted for BUD42DT4G?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUD42DT4G transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BUD42DT4G?
BUD42DT4G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BUD42DT4G 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 BUD42DT4G?
For technical support, including BUD42DT4G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUD42DT4G requirements.
6.How does Aetrix verify that BUD42DT4G is sourced from the original manufacturer or authorized distributors?
All BUD42DT4G 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 BUD42DT4G meets industry standards.
7.What is the process for return or replacement of BUD42DT4G?
All BUD42DT4G units undergo pre-shipment inspection (PSI). If there is an issue with BUD42DT4G, 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 BUD42DT4G part is unused and in its original packaging.
Return procedure for BUD42DT4G:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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