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

STMicroelectronics ST5027

Name: ST5027
Brand: STMicroelectronics
SKU: ST5027
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ST5027

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: ST5027.pdf

Description:: TRANS NPN 800V 3A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:2,208

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Product details

Overview

ST5027 from STMicroelectronics is an NPN high-voltage bipolar power transistor designed for horizontal deflection and high-power lighting applications in CRT TVs, monitors, and electronic ballasts. It features V_CEO = 800 V, V_CES = 1200 V, I_C = 3 A, P_tot = 90 W, and TO-220 package - enabling reliable operation in single-lamp 36W fluorescent ballast circuits with 220V mains input.

For engineers reviewing the ST5027 datasheet, ST5027 pinout, ST5027 application, or ST5027 equivalent, key selection criteria include its 800V collector-emitter breakdown rating, 3A continuous current capability, 90W thermal dissipation in TO-220, and suitability for resonant flyback and voltage-fed half-bridge topologies in lamp ballasts and TV deflection stages.

Technical Context

The ST5027 operates as a ruggedized NPN switching transistor optimized for high-voltage, medium-current linear and switching applications. Its 1200V V_CES rating supports safe operation under inductive load turn-off transients, while its h_FE range (min 5 at I_C = 1.5 A, V_CE = 5 V) ensures stable base drive requirements in fixed-bias deflection circuits.

Designed for use in voltage-fed horizontal deflection output stages and high-efficiency electronic ballasts, it delivers low V_CE(sat) (1.5 V typical at I_C = 3 A, I_B = 0.3 A), enabling reduced conduction losses and simplified heatsinking in compact 36W lamp drivers.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	800 V - Withstands 800V collector-emitter voltage under open-base conditions, suitable for 220V AC mains-derived supply rails with margin.
V_CES	1200 V - Sustains 1200V with emitter shorted to base, critical for snubberless flyback and inductive energy recovery in deflection circuits.
I_C	3 A - Continuous collector current rating enables driving 36W lamps in single-tube configurations without derating at 25°C ambient.
P_tot	90 W - Total power dissipation at T_c = 25°C allows direct mounting on moderate heatsinks for thermally constrained ballast PCBs.
Package	TO-220 - Standard through-hole power package with isolated tab, compatible with automated assembly and standard heatsink clips.
h_FE	5 (min) @ I_C = 1.5 A - Low, stable DC current gain simplifies fixed-base drive design and improves switching consistency in analog-controlled ballasts.

Pinout & Package

ST5027 is housed in a TO-220 package with electrically isolated collector tab. The device uses standard three-terminal configuration: Pin 1 = Base, Pin 2 = Collector (tab), Pin 3 = Emitter.

Pin/Terminal	Circuit Role	Design Meaning
Base (Pin 1)	Control input	Receives low-current drive signal; requires ~0.3 A base current to saturate at 3 A collector load.
Collector (Pin 2 / Tab)	High-voltage power output	Connected to primary winding of deflection yoke or ballast transformer; tab must be electrically isolated from heatsink unless specified.
Emitter (Pin 3)	Current return path	Common reference node for base drive and load return; placed adjacent to ground plane for minimal loop inductance in switching paths.

Key Features

Feature	Design Value
High V_CES rating	1200 V enables snubberless operation in resonant flyback deflection stages, reducing component count and board space.
Low V_CE(sat)	1.5 V typical at full 3 A load minimizes conduction loss and thermal stress in continuous-duty lamp ballasts.
TO-220 mechanical robustness	Standard footprint supports manual rework, automated insertion, and reliable thermal interface with clip-on heatsinks.
Stable h_FE at high V_CE	Guaranteed minimum gain up to 800 V ensures predictable turn-on behavior across line-voltage variations in 220V/277V systems.

Applications

Compact Fluorescent Lamp Ballast

Horizontal Deflection Output Stage

Use Scenario: Single 36W T8 fluorescent tube driven from 220V AC mains using voltage-fed half-bridge topology.

IC Role / Device Role / Timing Role: Main switching transistor in resonant inverter stage; switches at 20–50 kHz to sustain lamp arc and regulate power.

Use Value: 800V V_CEO and 1200V V_CES eliminate need for external snubbers, reducing BOM cost and improving reliability over 10,000-hour lamp life.

Use Scenario: Horizontal output stage in 21-inch CRT TV chassis operating at 15.625 kHz line frequency.

IC Role / Device Role / Timing Role: High-voltage switch controlling flyback energy transfer to deflection yoke and EHT generation circuit.

Use Value: 90W P_tot and low V_CE(sat) allow stable operation without forced air cooling, supporting fanless TV designs.

Industrial Lamp Ballast

Electronic Transformer for Halogen Lamps

Use Scenario: 36W industrial-grade lamp driver for warehouse lighting with wide input voltage tolerance (220–240V AC).

IC Role / Device Role / Timing Role: Primary-side switch in self-oscillating Royer converter powering high-intensity discharge lamps.

Use Value: Robust SOA (Safe Operating Area) up to 100°C case temperature ensures uninterrupted operation in enclosed fixtures.

Use Scenario: 35W electronic transformer replacing magnetic transformer in 12V halogen downlight systems.

IC Role / Device Role / Timing Role: Half-bridge switch controlling high-frequency AC output to step-down transformer primary.

Use Value: TO-220 package enables direct mounting to aluminum housing for passive thermal management in compact enclosures.

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
BUL216	V_CEO = 800 V, V_CES = 1600 V, I_C = 4 A, P_tot = 90 W - higher V_CES and I_C, same package.	Supports higher peak currents in multi-lamp ballasts or 4×32W systems; not optimized for single 36W timing-critical deflection.	Select when extended voltage margin or higher surge current handling is required beyond ST5027's 3A rating.
BUL416	V_CEO = 800 V, V_CES = 1600 V, I_C = 6 A, P_tot = 110 W - higher current and power, same TO-220 footprint.	Targeted at 6×32W multi-lamp systems or high-reliability industrial SMPS where 3A headroom is insufficient.	Choose only if system-level testing confirms improved thermal stability under sustained 6A pulsed loads.

Compared with BUL216 and BUL416, ST5027 offers tighter h_FE control and proven performance in 36W single-lamp ballasts and 15kHz CRT deflection - making it the optimal choice where precise gain matching and legacy design compatibility are prioritized over raw current headroom.

Availability

ST5027 is available at Aetrix Electronics and suitable for compact fluorescent lamp ballasts, horizontal deflection output stages, and industrial electronic transformers requiring stable component supply, long-term lifecycle support, and traceable manufacturing origin.

Supply support for ST5027 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 management, analog, and discrete devices for industrial, automotive, and consumer markets.

ST5027 belongs to ST's high-voltage bipolar transistor product line, engineered specifically for horizontal deflection and electronic lighting ballast applications - emphasizing ruggedness, consistent gain, and thermal reliability in high-stress analog switching environments.

FAQ

Is ST5027 pin-compatible with ST13007 or ST13009?

No. ST5027 is an NPN transistor in TO-220 package with base-collector-emitter pinout (1-2-3). ST13007 and ST13009 share the same pinout but differ in V_CEO (400 V), I_C (8 A / 12 A), and P_tot (80 W / 100 W). Substitution requires verification of SOA, drive strength, and thermal design - not drop-in compatible.

Does ST5027 include an integrated freewheeling diode?

No. ST5027 is a discrete NPN bipolar junction transistor without any integrated diode. The "D" suffix (e.g., ST13005D) indicates built-in freewheeling diode; ST5027 has no such feature and requires external flyback protection in inductive switching applications.

What is the maximum operating junction temperature for ST5027?

The absolute maximum junction temperature (T_j) for ST5027 is 150°C, as specified in ST's official documentation. Derating is required above 25°C case temperature; at T_c = 100°C, maximum allowable P_tot drops to approximately 45 W per thermal resistance data in the datasheet.

Can ST5027 be used in PFC boost stages?

No. ST5027 is not optimized for power factor correction applications. Its relatively low h_FE and lack of fast-switching characterization (no t_f/t_r specs) make it unsuitable for high-frequency (≥50 kHz) PFC controllers. Use dedicated MOSFETs or IGBTs like STW48N60M2 for such topologies.

ST5027 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 3 A

Voltage - Collector Emitter Breakdown (Max):: 800 V

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: -

Power - Max:: 90 W

Frequency - Transition:: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

ST5027 FAQ

1.How can I place an order for ST5027 through Aetrix?

Please submit a Request for Quotation (RFQ) for ST5027 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 ST5027 reliable?

The price and inventory of ST5027 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ST5027 is usually 5 days.

3.What payment methods are accepted for ST5027?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ST5027 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ST5027?

ST5027 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ST5027 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 ST5027?

For technical support, including ST5027 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ST5027 requirements.

6.How does Aetrix verify that ST5027 is sourced from the original manufacturer or authorized distributors?

All ST5027 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 ST5027 meets industry standards.

7.What is the process for return or replacement of ST5027?

All ST5027 units undergo pre-shipment inspection (PSI). If there is an issue with ST5027, 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 ST5027 part is unused and in its original packaging.

Return procedure for ST5027:

1.Submit a request within 90 days.

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

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