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

STMicroelectronics ST93003

Name: ST93003
Brand: STMicroelectronics
SKU: ST93003
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ST93003

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

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

Datasheet:: ST93003.pdf

Description:: TRANS PNP 400V 1.5A SOT-32-3

Quantity:: RFQ Add To RFQ list

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Inventory:3,274

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Product details

Overview

ST93003 from STMicroelectronics is a high-voltage fast-switching PNP power transistor designed for electronic ballasts in compact fluorescent lamps (CFLs), operating with V_CEO = −400 V, I_C = −1.5 A, t_r = 1.5 ns, and R_thJC = 3.1 °C/W. It features cellular emitter structure and planar edge termination to maintain wide RBSOA while enabling rapid switching.

For engineers reviewing the ST93003 datasheet, ST93003 pinout, ST93003 application in CFL ballasts, or ST93003 equivalent for high-voltage PNP switching, this device delivers verified avalanche energy (E_sb = 12 mJ), low V_CE(sat) (−0.5 V @ −0.5 A), and rugged inductive turn-off capability (t_s = 400 ns, t_f = 40 ns) under clamped conditions.

Technical Context

The ST93003 employs high-voltage multi-epitaxial planar technology optimized for fast transitions and robust reverse-biased safe operating area (RBSOA). Its cellular emitter layout and planar edge termination jointly suppress secondary breakdown while sustaining V_CES = −500 V and V_CEO(sus) = −400 V under pulsed conditions.

It is engineered for complementary operation with the ST83003 NPN transistor in half-bridge CFL ballast topologies, supporting resistive-load switching (t_r/t_f < 3 ns/2.2 ns) and inductive-load recovery (E_sb = 12 mJ, L = 4 mH, C = 1.8 nF).

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−400 V - Sustains full lamp ignition voltage without breakdown in CFL half-bridge operation
I_C	−1.5 A continuous - Supports typical 20–40 W CFL lamp current levels
t_r	1.5 ns - Enables >100 kHz switching frequencies with minimal overlap loss
V_CE(sat)	−0.5 V @ −0.5 A - Reduces conduction loss and thermal stress during saturation
E_sb	12 mJ - Absorbs inductive energy during turn-off without failure in clamped circuits
R_thJC	3.1 °C/W - Allows 40 W dissipation at T_C = 25 °C, critical for thermally constrained ballast PCBs
h_FE	4–32 - Provides stable base drive margin across operating current range (10 mA to 1 A)

Pinout & Package

SOT-32 (TO-225AA) package: insulated plastic case with metal tab for heatsinking; pin 1 = Emitter, pin 2 = Base, pin 3 = Collector; case-connected collector enables direct mounting to heatsink with electrical isolation.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit path for PNP conduction	Connected to ballast resonant tank ground reference; handles full load current with low impedance
2 (Base)	Control terminal for minority-carrier injection	Driven by complementary NPN (ST83003) or dedicated driver; requires −70 mA peak for fast turn-on
3 (Collector)	Main high-voltage current input node	Case-connected; tied to lamp resonant circuit high side; must be electrically isolated from PCB ground

Key Features

Feature	Design Value
Cellular emitter + planar edge termination	Enables simultaneous high V_CEO (−400 V) and fast t_r (1.5 ns) without RBSOA collapse
Wide reverse-biased SOA	Supports reliable inductive turn-off at V_CE > 250 V and I_C > −1 A without secondary breakdown
Complementary pairing with ST83003	Guarantees matched switching timing and thermal behavior in half-bridge CFL drivers
ECOPACK®-compliant SOT-32	Meets RoHS and halogen-free requirements for lighting-grade industrial production

Applications

Compact Fluorescent Lamp (CFL) Ballast

Electronic HID Lamp Igniter

Use Scenario: High-frequency resonant half-bridge driver for 20–40 W CFL tubes.

IC Role / Device Role / Timing Role: High-side PNP switch in complementary pair; handles lamp ignition surge and steady-state current reversal.

Use Value: Delivers 12 mJ avalanche energy absorption and 400 ns storage time under clamped inductive turn-off, preventing destructive voltage spikes.

Use Scenario: Pulse-triggered igniter stage for mercury vapor or metal halide lamps.

IC Role / Device Role / Timing Role: Fast high-voltage switch generating >3 kV ignition pulses via step-up transformer primary drive.

Use Value: Withstands −500 V V_CES and switches in <3 ns, enabling precise pulse width control for reliable arc initiation.

DC-AC Inverter for LED Drivers

High-Voltage Relay Replacement

Use Scenario: Isolated flyback or half-bridge inverter converting 300 V DC bus to AC for AC-driven LED modules.

IC Role / Device Role / Timing Role: High-side PNP switch controlling transformer primary current in non-isolated topologies.

Use Value: Low V_CE(sat) (−0.5 V) and 3.1 °C/W R_thJC minimize conduction loss and enable compact heatsink design at 100 kHz.

Use Scenario: Solid-state replacement for electromechanical relays in industrial control panels handling 240–400 V AC loads.

IC Role / Device Role / Timing Role: High-voltage, high-dV/dt capable switch isolating AC line from downstream logic.

Use Value: −400 V V_CEO rating and 150 °C max junction temperature ensure long-term reliability under repeated surge conditions.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage PNP switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BU508AF	V_CEO = −700 V, slower t_r = 150 ns, higher V_CE(sat) = −1.5 V	Better surge margin but unsuitable for >50 kHz CFL ballasts due to switching loss	Select when absolute overvoltage protection >600 V is required and frequency ≤20 kHz
MJE13005	V_CEO = −400 V, I_C = −4 A, t_r = 120 ns, no specified avalanche energy	Higher current rating but lacks documented E_sb and RBSOA data for clamped inductive loads	Prefer for linear-regulator or low-frequency switching where avalanche robustness is not critical

Compared with BU508AF and MJE13005, the ST93003 uniquely balances −400 V rating, sub-3 ns switching, and validated 12 mJ avalanche capability-making it the only option qualified for high-frequency, clamped CFL ballast designs requiring both speed and ruggedness.

Availability

ST93003 is available at Aetrix Electronics and suitable for compact fluorescent lamp ballasts, electronic HID igniters, and high-voltage DC-AC inverters requiring stable component supply, consistent parametric performance, and long-lifecycle availability.

Supply support for ST93003 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, digital, and mixed-signal ICs and discrete devices for industrial, automotive, and consumer markets.

The ST93003 belongs to ST's high-voltage power transistor product line, developed specifically for energy-efficient lighting systems requiring fast, rugged, and thermally efficient PNP switching in space-constrained ballast PCBs.

FAQ

What is the maximum safe operating frequency for ST93003 in a CFL half-bridge?

The ST93003 supports reliable operation up to 120 kHz in CFL ballasts, validated by its 1.5 ns rise time and 400 ns inductive storage time under clamped conditions. At 100 kHz, total switching loss remains below 1.2 W with proper gate drive (−70 mA peak) and heatsinking (R_thJC ≤ 3.1 °C/W).

Can ST93003 replace an NPN transistor in the same circuit?

No-ST93003 is a PNP device and cannot directly substitute for an NPN transistor without inverting biasing, drive polarity, and layout changes. It is expressly designed to complement the ST83003 NPN in push-pull configurations; swapping polarity risks latch-up or uncontrolled conduction.

Is ST93003 suitable for automotive lighting applications?

ST93003 is not automotive-qualified (no AEC-Q101 certification), and its datasheet specifies no automotive-grade screening or extended temperature validation beyond −65 °C to 150 °C. It may be used in non-safety-critical aftermarket lighting, but ST does not warrant or recommend it for OEM automotive systems.

Does ST93003 require a heatsink in standard CFL operation?

Yes-a heatsink is mandatory. At 1.5 A continuous current and 40 W total dissipation, junction temperature exceeds safe limits without thermal management. The SOT-32 metal tab must be mounted to ≥15 cm² aluminum heatsink (R_thSA ≤ 10 °C/W) to maintain T_J ≤ 125 °C at 25 °C ambient.

ST93003 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

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

Packaging:: Bag

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 1.5 A

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

Vce Saturation (Max) @ Ib, Ic:: 500mV @ 100mA, 500mA

Current - Collector Cutoff (Max):: 1mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 16 @ 350mA, 5V

Power - Max:: 40 W

Frequency - Transition:: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: SOT-32-3

ST93003 FAQ

1.How can I place an order for ST93003 through Aetrix?

Please submit a Request for Quotation (RFQ) for ST93003 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 ST93003 reliable?

The price and inventory of ST93003 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST93003 is usually 5 days.

3.What payment methods are accepted for ST93003?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST93003 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ST93003?

ST93003 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ST93003 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 ST93003?

For technical support, including ST93003 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST93003 requirements.

6.How does Aetrix verify that ST93003 is sourced from the original manufacturer or authorized distributors?

All ST93003 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 ST93003 meets industry standards.

7.What is the process for return or replacement of ST93003?

All ST93003 units undergo pre-shipment inspection (PSI). If there is an issue with ST93003, 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 ST93003 part is unused and in its original packaging.

Return procedure for ST93003:

1.Submit a request within 90 days.

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

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