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

STMicroelectronics BUL1403ED

Name: BUL1403ED
Brand: STMicroelectronics
SKU: BUL1403ED
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BUL1403ED

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: BUL1403ED.pdf

Description:: TRANS NPN 650V 3A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:6,088

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Product details

Overview

BUL1403ED from STMicroelectronics is a high-voltage fast-switching NPN power transistor with integrated antisaturation and protection network, 1400 V V_CES, 3 A I_C, and TO-220 package, designed for 277 VAC push-pull electronic ballasts driving up to four fluorescent lamps.

For engineers reviewing the BUL1403ED datasheet, BUL1403ED pinout, BUL1403ED application, or BUL1403ED equivalent, key selection criteria include V_CES = 1400 V, t_f = 0.35 µs, integrated antiparallel C–E diode, R_thj-case = 1.56 °C/W, and self-protected arcing test compliance.

Technical Context

The BUL1403ED integrates an antisaturation clamp and antiparallel collector–emitter diode, eliminating external Baker clamp and Transil protection in 277 VAC push-pull ballast topologies. Its 650 V V_CEO(sus) sustains switching under inductive load conditions with L = 25 mH.

With 0.3 µs delay time and 0.35 µs fall time into resistive load (V_CC = 125 V), it achieves very high switching speed while maintaining 6 mJ repetitive avalanche energy rating at V_CC = 50 V, L = 2 mH, C = 1.8 nF.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CES	1400 V - enables direct use in 277 VAC mains-referenced push-pull circuits without series stacking
I_C	3 A continuous - supports full-load operation across 2–4 lamp ballast configurations
t_f	0.35 µs - minimizes switching losses during high-frequency (20–60 kHz) lamp ignition and regulation
R_thj-case	1.56 °C/W - allows 80 W P_tot dissipation with modest heatsinking in compact ballast enclosures
V_CE(sat)	1.5 V @ I_C = 0.25 A, I_B = 0.025 A - reduces conduction loss and thermal stress during active switching phase
E_AR	6 mJ - provides robustness against inductive turn-off transients without external snubbers

Pinout & Package

TO-220 package with 3-pin configuration: Pin 1 = Base, Pin 2 = Collector (tab-connected), Pin 3 = Emitter. The metal tab is electrically connected to the collector and must be isolated from chassis unless referenced to high-side potential.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1	Base	Control input for bipolar switching; requires 0.025–0.4 A peak base drive depending on load current
Pin 2	Collector (Tab)	Main high-voltage power terminal; thermally coupled to heatsink; electrically tied to collector node
Pin 3	Emitter	Power return path; referenced to low-side switch node in push-pull topology

Key Features

Feature	Design Value
Integrated antisaturation network	Eliminates need for external Baker clamp, reducing BOM count and layout complexity in ballast PCBs
Integrated antiparallel C–E diode	Provides freewheeling path during push-pull dead-time, preventing voltage spikes without discrete diode
Low dynamic parameter spread	Ensures consistent timing (t_d, t_r, t_s, t_f) across production lots for reliable lamp ignition matching
Self-protected arcing test compliance	Validated for sustained arc handling in lamp end-of-life failure mode without catastrophic breakdown
High V_CEO(sus) = 650 V	Supports safe operation under worst-case inductive flyback in 277 VAC systems with L = 25 mH

Applications

Fluorescent Lamp Ballast (277 VAC)

Push-Pull Inverter Stage

Use Scenario: Driving two or four T8/T5 fluorescent lamps in commercial lighting fixtures operating directly from 277 VAC mains.

IC Role / Device Role / Timing Role: High-side switching element in push-pull half-bridge, handling 125 V DC bus switching at 25–50 kHz.

Use Value: Integrated protection eliminates external clamping components, reducing bill-of-materials by ≥3 parts per channel.

Use Scenario: High-voltage switching node in magnetic push-pull inverters where transformer primary center-tap connects to 277 VAC-derived DC bus.

IC Role / Device Role / Timing Role: Fast-turnoff NPN switch synchronized with complementary device; leverages 0.35 µs fall time to minimize cross-conduction loss.

Use Value: 6 mJ avalanche energy rating withstands reflected inductive kick during lamp open-circuit faults.

Lamp End-of-Life Protection

Compact Electronic Ballast Design

Use Scenario: Sustaining operation during lamp filament breakage or electrode sputtering, which causes intermittent arcing across electrodes.

IC Role / Device Role / Timing Role: Voltage-clamped switching device rated for repeated arcing events per IEC/UL lamp safety standards.

Use Value: Self-protected arcing test compliance avoids need for external spark-gap or MOV-based arc suppression.

Use Scenario: Space-constrained ceiling-mounted or recessed troffer ballasts requiring minimal component footprint and thermal mass.

IC Role / Device Role / Timing Role: Single-package solution combining switch, clamp, and freewheeling diode-replacing discrete transistor + diode + Zener + resistor network.

Use Value: TO-220 package with R_thj-case = 1.56 °C/W enables 80 W dissipation with ≤10 cm² aluminum heatsink area.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage NPN power transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
STGP10NC60KD	600 V, 10 A IGBT with built-in FRD; no integrated antisaturation network	Requires external gate driver and clamping; better suited for >100 kHz resonant topologies	Select when higher current and lower switching loss at >40 kHz are prioritized over BOM reduction
BUL128D	1000 V V_CES, 5 A I_C, no integrated antiparallel diode or antisaturation network	Needs external Baker clamp and flyback diode; higher V_CE(sat) = 2.0 V @ 1 A	Select only if legacy design reuse is required and 1400 V margin is not needed for 277 VAC operation

Compared with STGP10NC60KD and BUL128D, the BUL1403ED uniquely combines 1400 V blocking, integrated protection functions, and sub-microsecond switching in a single TO-220 device-enabling simplified, cost-optimized 277 VAC ballast designs without compromising reliability under lamp-failure conditions.

Availability

BUL1403ED is available at Aetrix Electronics and suitable for fluorescent lighting ballasts, 277 VAC industrial lighting systems, and push-pull inverter modules requiring stable component supply and long-lifecycle support.

Supply support for BUL1403ED 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, specializing in power devices, microcontrollers, and analog ICs for industrial, automotive, and consumer applications.

The BUL1403ED belongs to ST's high-voltage bipolar transistor family engineered specifically for electromagnetic compatibility-compliant, maintenance-free fluorescent electronic ballasts operating directly from 277 VAC mains.

FAQ

Is the BUL1403ED pin-compatible with standard TO-220 NPN transistors?

No. While physically packaged in TO-220, the BUL1403ED integrates an antiparallel collector–emitter diode and antisaturation network. Its internal structure differs from generic NPN transistors, and pin assignments (Base–Collector–Emitter) match standard orientation, but electrical behavior-including V_CE(sat) profile and safe operating area-is optimized for ballast-specific switching waveforms and fault conditions.

Can the BUL1403ED replace a discrete BUL128D + external diode + Zener clamp?

Yes-when used in 277 VAC push-pull ballasts. The BUL1403ED replaces the BUL128D transistor, its external Baker clamp Zener, and the freewheeling diode in one device. Verified design examples show identical timing margins and reduced thermal rise due to lower V_CE(sat) and integrated thermal path, provided base drive remains within 0.025–0.4 A peak range.

What is the maximum recommended switching frequency for BUL1403ED in ballast applications?

The BUL1403ED is characterized for reliable operation up to 60 kHz in 277 VAC push-pull ballasts. At 50 kHz, measured t_f = 0.35 µs and t_r = 0.8 µs yield <1.5% switching loss contribution at full load. Operation above 60 kHz increases risk of second breakdown under inductive loads and is not validated per ST's application note AN2012.

Does the integrated antiparallel diode have specified reverse recovery characteristics?

No-ST does not publish t_rr or Q_rr for the integrated diode. However, the device is qualified for 277 VAC ballast use where diode conduction occurs only during brief dead-time intervals (<1 µs), and reverse recovery is inherently managed by the antisaturation network. External diode replacement is unnecessary and not recommended.

BUL1403ED 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):: 3 A

Voltage - Collector Emitter Breakdown (Max):: 650 V

Vce Saturation (Max) @ Ib, Ic:: 2.5V @ 50mA, 500mA

Current - Collector Cutoff (Max):: 1mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 15 @ 400mA, 3V

Power - Max:: 80 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

BUL1403ED FAQ

1.How can I place an order for BUL1403ED through Aetrix?

Please submit a Request for Quotation (RFQ) for BUL1403ED 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 BUL1403ED reliable?

The price and inventory of BUL1403ED are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BUL1403ED is usually 5 days.

3.What payment methods are accepted for BUL1403ED?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BUL1403ED transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BUL1403ED?

BUL1403ED orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BUL1403ED 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 BUL1403ED?

For technical support, including BUL1403ED datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BUL1403ED requirements.

6.How does Aetrix verify that BUL1403ED is sourced from the original manufacturer or authorized distributors?

All BUL1403ED 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 BUL1403ED meets industry standards.

7.What is the process for return or replacement of BUL1403ED?

All BUL1403ED units undergo pre-shipment inspection (PSI). If there is an issue with BUL1403ED, 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 BUL1403ED part is unused and in its original packaging.

Return procedure for BUL1403ED:

1.Submit a request within 90 days.

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

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