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

STMicroelectronics BUL310FP

Name: BUL310FP
Brand: STMicroelectronics
SKU: BUL310FP
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BUL310FP

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3 Full Pack

Datasheet:: BUL310FP.pdf

Description:: TRANS NPN 500V 5A TO-220FP

Quantity:: RFQ Add To RFQ list

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Inventory:4,289

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Product details

Overview

BUL310FP from STMicroelectronics is a high-voltage, fast-switching NPN power transistor in TO-220FP package, rated for 1000 V_CE, 5 A continuous collector current, and fully characterized at 125 °C. It features 2000 V DC insulation (UL compliant), large reverse-biased safe operating area (RBSOA), and sub-2 µs storage time-designed specifically for horizontal deflection in color TV and electronic ballasts.

For engineers reviewing the BUL310FP datasheet, BUL310FP pinout, BUL310FP application, or BUL310FP equivalent, key selection criteria include its 1000 V blocking capability, 1.2 µs typical storage time at 25 °C, 150 °C max junction temperature, UL-rated insulated package, and validated performance under inductive switching at elevated temperature.

Technical Context

The BUL310FP employs Multi Epitaxial Planar technology with cellular emitter and planar edge termination to simultaneously achieve high voltage endurance and fast switching. Its RBSOA is optimized for inductive loads, supporting reliable operation with L = 200 µH, V_CL = 250 V, and I_C = 2 A under pulsed conditions.

It is fully characterized at T_case = 125 °C, delivering verified V_CEO(sus) = 500 V, t_f = 150 ns, and t_s = 1.8 µs under high-temperature inductive switching-critical for fluorescent lamp ballast and flyback converter reliability.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CES	1000 V - Enables direct use in 400–800 V DC bus applications without series stacking
I_C (continuous)	5 A - Supports sustained power handling up to 36 W at T_c = 25 °C
t_s (25 °C)	1.2 µs - Reduces switching loss during turn-off in high-frequency horizontal deflection circuits
R_thj-case	3.5 °C/W - Allows thermal design with standard heatsinks for <10 W dissipation at 125 °C case temp
Insulation rating	2000 V DC (UL compliant) - Permits safe primary-side mounting without additional isolation barriers
V_CE(sat) @ 3 A	1.1 V - Limits conduction loss to <3.3 W at full load, improving efficiency in low-power SMPS
T_j(max)	150 °C - Enables operation in sealed lamp housings and compact TV chassis with limited airflow

Pinout & Package

TO-220FP package: fully molded, insulated plastic housing with metal tab (pin 2) electrically isolated from collector (pin 1); pin 3 is emitter. Integral insulation eliminates need for insulating washers in heatsink mounting.

Pin/Terminal	Circuit Role	Design Meaning
1 (Tab side)	Collector	High-voltage output node; connected to heatsink via insulated mounting (2000 V DC isolation)
2 (Middle)	Base	Low-impedance drive input; requires 0.4 A peak for full saturation at 3 A I_C
3 (Opposite tab)	Emiter	Reference return path; tied to ground or low-side switch node in flyback/forward topologies

Key Features

Feature	Design Value
Cellular Emitter Structure	Enables uniform current distribution and suppresses secondary breakdown during inductive turn-off
Planar Edge Termination	Extends voltage blocking capability to 1000 V while minimizing leakage at high temperature
Full 125 °C Characterization	Guarantees t_s ≤ 1.9 µs and V_CEO(sus) ≥ 500 V under real-world thermal stress
Low Dynamic Parameter Spread	Ensures consistent timing and loss behavior across production lots-critical for mass-produced TV deflection stages

Applications

Horizontal Deflection in CRT TVs

Electronic Ballasts for Fluorescent Lamps

Use Scenario: Driving flyback transformer in line-scan circuit of color television sets, operating at ~15.734 kHz with high-voltage retrace pulses.

IC Role / Device Role / Timing Role: High-voltage switching element controlling energy transfer and horizontal sweep timing.

Use Value: 1000 V_CES withstands retrace spikes; 1.2 µs t_s ensures precise blanking window control and minimal trace distortion.

Use Scenario: High-frequency (20–60 kHz) half-bridge or single-transistor resonant inverter driving 4–80 W fluorescent tubes.

IC Role / Device Role / Timing Role: Primary-side power switch regulating lamp current via frequency-controlled resonant tank.

Use Value: Large RBSOA prevents failure during lamp ignition transients; UL-rated insulation simplifies PCB layout and safety certification.

Flyback Converters (≤30 W)

Forward Converters (Low-Power)

Use Scenario: Isolated AC/DC adapter or auxiliary supply for industrial controls, delivering 5–24 V at ≤1 A.

IC Role / Device Role / Timing Role: Primary-side switch storing and releasing energy in transformer core per cycle.

Use Value: 5 A I_C and 36 W P_tot support 25–30 W output; 150 °C T_j(max) allows compact enclosure designs.

Use Scenario: Single-transistor forward converter for telecom or embedded system auxiliary rails (e.g., 12 V @ 0.5 A).

IC Role / Device Role / Timing Role: Synchronized main switch transferring energy directly through transformer during duty cycle.

Use Value: Fast t_f (150 ns @ 125 °C) minimizes dead-time losses; low V_CE(sat) reduces conduction loss at medium load.

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
STBUL741	Higher V_CES = 1500 V; lower I_C = 3 A; slower t_s = 2.5 µs	Better suited for >1 kV DC link applications; less optimal for high-frequency TV deflection	Select when absolute voltage margin outweighs switching speed requirements
BUL49D	Same TO-220FP package; V_CES = 1000 V; t_s = 1.5 µs (typ); no UL insulation rating	Lacks 2000 V DC isolation-requires external insulator for heatsink mounting	Choose only where cost sensitivity overrides safety certification needs

Compared with STBUL741 and BUL49D, the BUL310FP uniquely balances 1000 V capability, sub-2 µs storage time, and UL-certified insulation-making it the preferred choice for certified lighting and consumer display systems requiring both safety and timing precision.

Availability

BUL310FP is available at Aetrix Electronics and suitable for horizontal deflection circuits, electronic ballasts, and low-power flyback converters requiring stable component supply, long-lifecycle availability, and UL-compliant insulation.

Supply support for BUL310FP 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, designing and manufacturing analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The BUL series targets cost-sensitive, high-reliability power switching applications-including lighting, TV deflection, and low-power SMPS-where robustness at elevated temperature and tight parameter spread are essential.

FAQ

Is the BUL310FP pin-compatible with standard TO-220 transistors?

No-the BUL310FP uses TO-220FP (fully insulated package), where pin 1 (collector) is electrically isolated from the metal tab (pin 2). Standard TO-220 devices connect collector to the tab. Mounting requires non-conductive hardware and verification of creepage/clearance distances.

What is the maximum recommended gate/base drive for reliable switching?

The BUL310FP is a bipolar transistor requiring base current drive-not gate voltage. For 3 A collector current, 0.6 A DC base current is specified. Peak base current must not exceed 4 A (tp < 5 ms), and base-emitter reverse voltage must be limited to –5 V during turn-off to avoid degradation.

Can the BUL310FP replace the BU2508DF in CRT deflection circuits?

Not directly: BU2508DF has higher V_CEO (800 V) but lower V_CES (1500 V), different pinout (TO-3P), and no UL insulation. While both serve horizontal deflection, BUL310FP's TO-220FP form factor and 2000 V insulation require PCB layout changes and thermal recalculations before substitution.

Does the BUL310FP support operation above 100 °C case temperature?

Yes-it is fully characterized at 125 °C case temperature, with guaranteed parameters including t_s ≤ 1.9 µs and V_CEO(sus) ≥ 500 V. However, derating applies: total dissipation drops linearly above 25 °C at 3.5 °C/W, limiting usable power to ~20 W at T_c = 100 °C.

BUL310FP Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3 Full Pack

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 5 A

Voltage - Collector Emitter Breakdown (Max):: 500 V

Vce Saturation (Max) @ Ib, Ic:: 1.1V @ 600mA, 3A

Current - Collector Cutoff (Max):: 250µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 6 @ 3A, 2.5V

Power - Max:: 36 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220FP

BUL310FP FAQ

1.How can I place an order for BUL310FP through Aetrix?

Please submit a Request for Quotation (RFQ) for BUL310FP 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 BUL310FP reliable?

The price and inventory of BUL310FP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUL310FP is usually 5 days.

3.What payment methods are accepted for BUL310FP?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUL310FP transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUL310FP?

BUL310FP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUL310FP 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 BUL310FP?

For technical support, including BUL310FP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUL310FP requirements.

6.How does Aetrix verify that BUL310FP is sourced from the original manufacturer or authorized distributors?

All BUL310FP 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 BUL310FP meets industry standards.

7.What is the process for return or replacement of BUL310FP?

All BUL310FP units undergo pre-shipment inspection (PSI). If there is an issue with BUL310FP, 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 BUL310FP part is unused and in its original packaging.

Return procedure for BUL310FP:

1.Submit a request within 90 days.

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

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