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

STMicroelectronics BUL510

Name: BUL510
Brand: STMicroelectronics
SKU: BUL510
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BUL510

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: BUL510.pdf

Description:: TRANS NPN 450V 10A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:61

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Product details

Overview

BUL510 from STMicroelectronics is a high-voltage, fast-switching NPN power transistor in TO-220 package, rated for 1000 V V_CES, 10 A I_C, and 100 W P_tot at T_c = 25 °C. It employs Hollow Emitter structure and Multiepitaxial Mesa technology to achieve very high switching speed (t_f = 80 ns typ., t_s = 2.2 µs typ.) and low dynamic parameter spread, targeting electronic ballasts for fluorescent lighting.

For engineers reviewing the BUL510 datasheet, BUL510 pinout, BUL510 application, or BUL510 equivalent, key selection criteria include its 450 V V_CEO(sus) under inductive load, full characterization at 125 °C, R_thj-case = 1.25 °C/W, and suitability for cost-sensitive SMPS and halogen lamp electronic transformers.

Technical Context

The BUL510 is optimized for hard-switched inductive loads with specified RBSOA and SOA derating curves. Its Hollow Emitter design reduces minority carrier storage, enabling t_s = 2.2 µs and t_f = 80 ns at I_C = 4 A, V_CL = 300 V, and L = 200 µH.

It operates up to T_j = 150 °C with guaranteed h_FE ≥ 15 at I_C = 1 A, V_CE = 5 V, and exhibits low leakage: I_CES ≤ 100 µA at V_CE = 1000 V, T_c = 25 °C - critical for high-voltage hold-off integrity in lighting ballasts.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CES	1000 V - Enables direct interface with mains-referenced high-voltage rails in offline SMPS and electronic ballasts.
I_C	10 A continuous - Supports medium-power switching stages up to ~500 W with appropriate heatsinking.
t_f	80 ns typical - Reduces switching losses during turn-off in 20–100 kHz ballast and SMPS topologies.
R_thj-case	1.25 °C/W - Allows thermal design with standard TO-220 heatsinks for sustained 100 W dissipation at case temperature ≤ 25 °C.
h_FE	15–45 - Provides predictable base drive requirements for fixed-gain driver circuits without feedback compensation.
V_CE(sat)	0.8 V @ I_C = 3 A, I_B = 0.6 A - Minimizes conduction loss in saturated-switch operation, improving efficiency in resonant lamp drivers.

Pinout & Package

Package: TO-220 (3-pin, straight lead, insulated tab). Mounting surface is electrically connected to collector (Pin 2).

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Low-impedance return path; requires low-inductance PCB layout to preserve fast switching performance.
2 (Collector)	High-voltage output node	Internally tied to metal tab; must be electrically isolated from heatsink unless system ground reference permits.
3 (Base)	Control input	Receives current-driven signal; base resistor selection must ensure I_B ≥ 0.6 A for full saturation at I_C = 3 A.

Key Features

Feature	Design Value
Hollow Emitter structure	Reduces stored charge, enabling t_s = 2.2 µs and t_f = 80 ns - critical for zero-voltage switching (ZVS) compatibility in resonant ballasts.
Full 125 °C characterization	Guarantees h_FE, V_CE(sat), and leakage specs across industrial temperature range - eliminates derating uncertainty in enclosed lamp housings.
Low dynamic parameter spread	Ensures consistent timing and gain across production lots - simplifies batch calibration in mass-produced electronic transformers.
High V_CEO(sus) = 450 V	Supports reliable operation under inductive flyback transients in 230 VAC-fed ballasts without snubber overdesign.

Applications

Electronic Ballasts for Fluorescent Lighting

Switch-Mode Power Supplies

Use Scenario: High-frequency (20–60 kHz) series-resonant inverter driving T8/T5 fluorescent lamps with instant start.

IC Role / Device Role / Timing Role: Main switching transistor in half-bridge topology; handles 450 V peak collector voltage and 4 A peak current per half-cycle.

Use Value: Fast t_f and low t_s minimize dead-time losses and enable stable lamp ignition without preheat overshoot.

Use Scenario: 100–250 W offline flyback or forward converter for industrial control power rails.

IC Role / Device Role / Timing Role: Primary-side switching element operating at 50–100 kHz with 1000 V blocking capability across AC line surges.

Use Value: 1000 V V_CES rating eliminates need for voltage clamping in universal-input designs subjected to 1.5 kV surge tests.

Electronic Transformers for Halogen Lamps

DC-AC Inverters for Low-Voltage Lighting

Use Scenario: 12 V DC input converted to 12 V AC (50 kHz) for 20–50 W MR16 halogen lamps.

IC Role / Device Role / Timing Role: Saturated switch in push-pull or Royer oscillator configuration; switches at fixed frequency with low V_CE(sat).

Use Value: 0.8 V V_CE(sat) at 3 A reduces conduction loss by >30% vs. legacy bipolar transistors, improving thermal margin in compact enclosures.

Use Scenario: Battery-powered portable lighting inverters requiring high reliability and minimal EMI.

IC Role / Device Role / Timing Role: High-side switch in self-oscillating inverter; leverages low leakage (I_CES ≤ 100 µA) to prevent standby drain.

Use Value: Ultra-low I_CES at 1000 V ensures <10 µA total system standby current - extends battery life in emergency lighting applications.

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
BUL722	V_CES = 1500 V, I_C = 12 A, t_f = 120 ns - higher voltage rating but slower switching.	Better suited for 347/480 VAC industrial SMPS where dV/dt stress exceeds 1000 V, but less optimal for 20–60 kHz ballasts.	Select when absolute voltage margin >500 V is required and switching frequency ≤ 30 kHz.
BU508A	V_CES = 1500 V, I_C = 8 A, t_f = 250 ns - higher voltage, lower current, significantly slower.	Common in legacy TV horizontal deflection; lacks 125 °C characterization and has wider h_FE spread.	Only consider for cost-driven replacements where switching speed is non-critical and thermal validation is not required.

Compared with BUL722 and BU508A, the BUL510 delivers superior switching speed and tighter parameter distribution at 1000 V - making it the preferred choice for high-frequency, thermally constrained lighting inverters where consistency and efficiency are prioritized over extreme voltage headroom.

Availability

BUL510 is available at Aetrix Electronics and suitable for electronic ballasts for fluorescent lighting, switch-mode power supplies, and electronic transformers for halogen lamps requiring stable component supply and long-term manufacturability planning.

Supply support for BUL510 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The BUL series belongs to ST's high-voltage bipolar power transistor product line, engineered specifically for cost-effective, high-reliability switching in lighting and low-to-medium power SMPS applications - emphasizing ruggedness, thermal stability, and production consistency.

FAQ

Is BUL510 pin-compatible with TO-220 NPN transistors like BU2508DX?

No. BUL510 uses standard TO-220 pinout (E-C-B), but BU2508DX follows a different internal connection (C-E-B). Mechanical fit does not guarantee electrical compatibility. Always verify pin assignment using official STMicroelectronics documentation and cross-check base-emitter-collector terminal mapping before board-level substitution.

Can BUL510 operate reliably at 125 °C junction temperature?

Yes. The BUL510 is fully characterized at T_c = 125 °C, with guaranteed parameters including h_FE ≥ 10, V_CE(sat) ≤ 1.5 V, and t_s ≤ 3 µs. Its 150 °C maximum junction temperature and R_thj-case = 1.25 °C/W allow safe operation at full current when case temperature is maintained ≤ 125 °C via adequate heatsinking.

What is the recommended base drive for saturation switching?

For reliable saturation at I_C = 5 A, apply I_B ≥ 1.25 A (h_FE min ≈ 4). Use a base resistor calculated from V_BB − V_BE(sat) (1.5 V max), ensuring driver can source ≥1.25 A peak. Avoid linear-region operation: gate/base drive must transition rapidly between cutoff and full saturation to minimize switching losses.

Does BUL510 require a snubber network in inductive switching applications?

A snubber is recommended for inductive loads exceeding 200 µH or where V_CL > 300 V. The BUL510's RBSOA curve defines safe inductive switching limits; operation beyond these boundaries risks secondary breakdown. A simple RC snubber across C–E improves reliability in electronic ballasts and flyback converters by limiting dV/dt and clamping flyback spikes.

BUL510 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 10 A

Voltage - Collector Emitter Breakdown (Max):: 450 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 1.25A, 5A

Current - Collector Cutoff (Max):: 250µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 15 @ 1A, 5V

Power - Max:: 100 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

BUL510 FAQ

1.How can I place an order for BUL510 through Aetrix?

Please submit a Request for Quotation (RFQ) for BUL510 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 BUL510 reliable?

The price and inventory of BUL510 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUL510 is usually 5 days.

3.What payment methods are accepted for BUL510?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUL510 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUL510?

BUL510 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUL510 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 BUL510?

For technical support, including BUL510 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUL510 requirements.

6.How does Aetrix verify that BUL510 is sourced from the original manufacturer or authorized distributors?

All BUL510 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 BUL510 meets industry standards.

7.What is the process for return or replacement of BUL510?

All BUL510 units undergo pre-shipment inspection (PSI). If there is an issue with BUL510, 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 BUL510 part is unused and in its original packaging.

Return procedure for BUL510:

1.Submit a request within 90 days.

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

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