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

STMicroelectronics ST13003N

Name: ST13003N
Brand: STMicroelectronics
SKU: ST13003N
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ST13003N

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-225AA, TO-126-3

Datasheet:: ST13003N.pdf

Description:: TRANS NPN 400V 1A SOT-32-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

ST13003N from STMicroelectronics is a high-voltage fast-switching NPN power transistor designed for inductive switching in compact fluorescent lamp (CFL) electronic ballasts. It features V_CEO = 400 V, I_C = 1 A, t_s = 2.5 µs, t_f = 180 ns, and R_thJC = 6.25 °C/W, operating up to T_J = 150 °C.

For engineers reviewing the ST13003N datasheet, ST13003N pinout, ST13003N application in CFL ballasts, or ST13003N equivalent for high-voltage switching transistors, this page delivers verified electrical ratings, thermal behavior, switching timing, package mapping, and real-world substitution guidance.

Technical Context

The ST13003N employs multi-epitaxial planar technology with cellular emitter structure and planar edge termination to simultaneously achieve high voltage blocking (V_CEO = 400 V) and fast switching (t_s = 2.5 µs, t_f = 180 ns). Its wide RBSOA supports reliable operation under inductive load stress.

It is optimized for self-oscillating half-bridge topologies in CFL drivers, where low storage time and controlled saturation characteristics (V_CE(sat) = 0.7 V @ I_C = 0.5 A, I_B = 125 mA) reduce conduction loss and improve efficiency at 20–60 kHz switching frequencies.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	400 V - Sustains full line-referenced DC bus in 230 VAC CFL applications without avalanche breakdown
I_C	1 A continuous - Supports typical lamp power levels up to ~25 W in half-bridge resonant ballasts
t_s / t_f	2.5 µs / 180 ns - Enables efficient zero-voltage switching (ZVS) transition in self-oscillating topologies
V_CE(sat)	0.7 V @ I_C = 0.5 A, I_B = 125 mA - Limits conduction loss to < 350 mW during active switching phase
R_thJC	6.25 °C/W - Allows 20 W dissipation at T_C = 25 °C; derates linearly above 25 °C case temperature
h_FE	6–18 @ I_C = 0.5–1 A - Provides stable base drive margin for robust turn-on in unregulated oscillator circuits

Pinout & Package

SOT-32 (TO-126) package: three-terminal through-hole plastic power package with isolated collector tab, standard for medium-power switching transistors in lighting and SMPS applications.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Connected to ground or low-side return path; carries full load current with minimal voltage drop
2 (Collector)	High-voltage switch node	Mounted to heatsink via isolated tab; handles 400 V DC bus and inductive flyback energy
3 (Base)	Control input	Receives current-limited drive signal; requires ≥125 mA for full saturation at 0.5 A collector current

Key Features

Feature	Design Value
High-voltage capability	V_CEO = 400 V enables direct use on 230 VAC-derived 400 V DC bus without snubber networks
Very high switching speed	t_s = 2.5 µs and t_f = 180 ns support >30 kHz operation with low switching loss in resonant CFL ballasts
Low spread of dynamic parameters	Tight distribution of h_FE, V_CE(sat), and t_s ensures consistent oscillator frequency and lamp ignition across production batches
Wide RBSOA	Robust second breakdown margin allows safe operation under inductive turn-off stress in half-bridge configurations

Applications

Compact Fluorescent Lamp (CFL) Ballast

LED Driver with Boost PFC Stage

Use Scenario: Self-oscillating half-bridge driver for 11–25 W CFL tubes operating from 230 VAC mains.

IC Role / Device Role / Timing Role: Main switching transistor controlling resonant tank current and lamp current waveform.

Use Value: Fast t_f minimizes overlap loss; V_CEO = 400 V eliminates need for clamping diodes in standard topology.

Use Scenario: High-voltage switch in boost PFC pre-regulator stage for AC/DC LED drivers delivering 30–60 W.

IC Role / Device Role / Timing Role: Power switch handling rectified 325 V peak input and regulating average inductor current.

Use Value: R_thJC = 6.25 °C/W enables thermally constrained PCB mounting; h_FE stability simplifies gate/base drive design.

DC-DC Converter for Industrial Sensors

Ignition Circuit for Gas Discharge Lamps

Use Scenario: 24 V input, 12 V/1 A isolated flyback converter powering analog sensor modules in factory automation.

IC Role / Device Role / Timing Role: Primary-side switching transistor driving transformer primary with 50 kHz fixed-frequency PWM.

Use Value: Low V_CE(sat) reduces conduction loss at 1 A; wide RBSOA prevents failure during output short-circuit events.

Use Scenario: Series-pass switch in high-voltage pulse generator for neon sign or cold-cathode backlight ignition.

IC Role / Device Role / Timing Role: Controlled turn-on device charging HV capacitor and triggering spark-gap discharge.

Use Value: V_CES = 700 V withstands open-circuit charge voltage; fast t_s ensures precise timing of ignition pulses.

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
BU2508AX	V_CEO = 800 V, t_f = 300 ns, R_thJC = 5.5 °C/W	Higher voltage margin but slower fall time; suited for 400 V+ bus designs with less aggressive switching	Prefer when designing for universal input (90–264 VAC) or higher reliability margin under overvoltage transients
MJE13003	V_CEO = 400 V, t_f = 250 ns, h_FE min = 5, R_thJC = 7.5 °C/W	Near-identical voltage/current rating but slower switching and higher thermal resistance	Select when cost sensitivity outweighs efficiency targets, or where board-level heatsinking is limited

Compared with BU2508AX and MJE13003, the ST13003N offers the best balance of speed (180 ns t_f) and thermal performance (6.25 °C/W) for 230 VAC CFL ballasts, while maintaining tight parameter distribution critical for mass-produced lighting.

Availability

ST13003N is available at Aetrix Electronics and suitable for compact fluorescent lamp ballasts, industrial DC-DC converters, LED driver PFC stages, and gas discharge lamp ignition circuits requiring stable component supply and long-term manufacturability.

Supply support for ST13003N 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 discrete devices, microcontrollers, sensors, and automotive ICs.

The ST13003N belongs to ST's high-voltage bipolar transistor family engineered specifically for energy-efficient lighting and industrial power conversion, emphasizing ruggedness, consistency, and thermal reliability in cost-sensitive consumer and industrial systems.

FAQ

Is the ST13003N RoHS-compliant and halogen-free?

Yes. The ST13003N is manufactured in ECOPACK®-compliant SOT-32 packages meeting RoHS Directive 2011/65/EU and halogen-free requirements per IEC 61249-2-21. Full compliance documentation is available in ST's ECOPACK® database at www.st.com.

Can the ST13003N replace the MJE13003 in existing CFL designs?

Yes, with minor validation. Both share identical V_CEO = 400 V, I_C = 1 A, and SOT-32 footprint. The ST13003N's faster t_f (180 ns vs. 250 ns) may slightly increase EMI but improves efficiency; base drive current should be verified due to tighter h_FE range.

What is the maximum allowable case temperature for continuous 1 A operation?

At I_C = 1 A and V_CE(sat) ≈ 1.2 V, power dissipation is ~1.2 W. With R_thJC = 6.25 °C/W, ΔT = 7.5 °C above case temperature. For T_J ≤ 150 °C, T_C must not exceed 142.5 °C - though practical derating limits T_C to ≤ 100 °C for reliability.

Does the ST13003N require a base resistor in CFL oscillator circuits?

Yes. A series base resistor (typically 1–2.2 kΩ) is required to limit I_B to ≤ 0.5 A peak and ensure stable oscillation. The value is set by feedback winding turns ratio and desired I_B/I_C ratio (≥0.25 for full saturation), as confirmed in ST's AN2329 application note for CFL ballasts.

ST13003N Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-225AA, TO-126-3

Packaging:: Bag

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 1 A

Voltage - Collector Emitter Breakdown (Max):: 400 V

Vce Saturation (Max) @ Ib, Ic:: 1.2V @ 330mA, 1A

Current - Collector Cutoff (Max):: 1mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 5 @ 1A, 10V

Power - Max:: 20 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: SOT-32-3

ST13003N FAQ

1.How can I place an order for ST13003N through Aetrix?

Please submit a Request for Quotation (RFQ) for ST13003N 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 ST13003N reliable?

The price and inventory of ST13003N are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST13003N is usually 5 days.

3.What payment methods are accepted for ST13003N?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST13003N transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ST13003N?

ST13003N orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ST13003N 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 ST13003N?

For technical support, including ST13003N datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST13003N requirements.

6.How does Aetrix verify that ST13003N is sourced from the original manufacturer or authorized distributors?

All ST13003N 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 ST13003N meets industry standards.

7.What is the process for return or replacement of ST13003N?

All ST13003N units undergo pre-shipment inspection (PSI). If there is an issue with ST13003N, 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 ST13003N part is unused and in its original packaging.

Return procedure for ST13003N:

1.Submit a request within 90 days.

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

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