Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

STMicroelectronics STBV42D

Name: STBV42D
Brand: STMicroelectronics
SKU: STBV42D
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: STBV42D

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA)

Datasheet:: STBV42D.pdf

Description:: TRANS NPN 400V 1A TO-92-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:5,494

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

STBV42D from STMicroelectronics is a high-voltage fast-switching NPN power transistor with integrated free-wheeling diode, rated for V_CEO = 400 V, I_C = 1 A, and switching fall time t_f = 0.3 µs under inductive load. It employs multi-epitaxial planar technology and cellular emitter structure to achieve wide RBSOA and stable dynamic parameters, targeting compact fluorescent lamp (CFL) electronic ballasts.

For engineers reviewing the STBV42D datasheet, STBV42D pinout, STBV42D application, or STBV42D equivalent, key selection criteria include its 400 V collector-emitter sustaining voltage, 0.3 µs inductive fall time, integrated diode forward voltage of 1.7 V at 350 mA, TO-92 package thermal resistance of 125 °C/W, and suitability for high-frequency CFL driver stages requiring robust SOA and low spread in switching behavior.

Technical Context

This device operates as a self-protected switch in resonant or quasi-resonant CFL ballast topologies, where the integrated diode eliminates external flyback path components. Its planar edge termination and cellular emitter design jointly enable simultaneous high voltage blocking (V_CEO(sus) = 400 V) and fast turn-off (t_f = 0.3 µs) without compromising ruggedness.

The transistor is characterized under pulsed conditions (≤300 µs, ≤2% duty cycle) for V_CEO(sus), and DC-tested for h_FE (12–30 at I_C = 5–0.8 A), V_CE(sat) (0.2–0.5 V across 0.25–0.75 A), and thermal resistance R_thJC = 125 °C/W - all specified at T_case = 25 °C unless noted.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	400 V - Sustaining voltage with base open; defines maximum safe operating voltage in CFL half-bridge switches
t_f	0.3 µs - Inductive load fall time at I_C = 0.25 A, V_clamp = 300 V; enables >100 kHz ballast operation
V_F	1.7 V @ I_F = 350 mA - Forward voltage of integrated diode; reduces component count vs. discrete diode + BJT
R_thJC	125 °C/W - Junction-to-case thermal resistance; limits max continuous power dissipation to ~0.8 W at T_C = 100 °C
h_FE	12–30 - DC current gain range across I_C = 5 mA to 0.8 A; supports stable base drive design in linear/switching hybrid modes
V_CE(sat)	0.2–0.5 V - Saturation voltage across 0.25–0.75 A; determines conduction loss in primary-side switching stage

Pinout & Package

STBV42D is housed in a standard TO-92 plastic package (bulk shipment), with lead configuration matching JEDEC TO-92 outline: Emitter (pin 1), Base (pin 2), Collector (pin 3), viewed from flat side with leads down.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Emitter)	Current return path for collector current	Connected to ground or low-side reference in CFL half-bridge; carries full load current during conduction
Pin 2 (Base)	Control input for bipolar conduction	Receives current-limited drive signal; requires ≥50 mA for full saturation at 0.25 A I_C
Pin 3 (Collector)	Main high-side current output node	Switches high-voltage AC bus (up to 400 V); connects to resonant tank and integrated diode anode

Key Features

Feature	Design Value
Integrated free-wheeling diode	Eliminates need for external diode in CFL resonant circuits, reducing PCB area and assembly cost
Low spread of dynamic parameters	Tight t_f distribution ensures consistent timing across production lots, critical for EMI-controlled ballast designs
Wide RBSOA with planar edge termination	Enables reliable operation under inductive switching stress without secondary breakdown at 400 V/1 A
Cellular emitter structure	Improves current sharing and switching uniformity, supporting stable gain and saturation voltage over temperature

Applications

Compact Fluorescent Lamp (CFL) Ballasts

Electronic Starter Circuits

Use Scenario: High-frequency resonant inverter driving 11–23 W CFL tubes with soft-start and end-of-life protection.

IC Role / Device Role / Timing Role: Main switching transistor in half-bridge topology; handles 400 V DC bus and provides fast zero-voltage switching transitions.

Use Value: Integrated diode and 0.3 µs t_f reduce component count and improve EMI profile versus discrete BJT+diode solutions.

Use Scenario: Preheat and ignition control circuit for instant-start CFLs using controlled current ramp and voltage spike generation.

IC Role / Device Role / Timing Role: Switched current source delivering precise preheat current (350 mA) via integrated diode forward conduction.

Use Value: Matched V_F = 1.7 V and h_FE stability ensure repeatable preheat timing and tube ignition reliability.

LED Driver Auxiliary Switches

Small-Signal HV Power Supplies

Use Scenario: Secondary-side synchronous rectifier or auxiliary bias switch in isolated LED drivers up to 25 W.

IC Role / Device Role / Timing Role: Low-loss freewheeling path during transformer reset; leverages integrated diode for reduced conduction loss.

Use Value: V_F = 1.7 V at 350 mA lowers heat generation compared to Schottky alternatives in cost-sensitive designs.

Use Scenario: Primary-side switch in <2 W offline flyback converters for sensor modules or IoT power rails.

IC Role / Device Role / Timing Role: Energy-transfer switch operating at 60–100 kHz with V_CEO = 400 V rating for universal AC input.

Use Value: R_thJC = 125 °C/W and TO-92 footprint allow thermally adequate operation without heatsink in low-power applications.

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
STB12NM60N	MOSFET (600 V, 12 A, TO-220); no integrated diode; gate-driven vs. current-driven	Requires external gate driver and flyback diode; better for >100 kHz, higher current, but higher BOM cost	Select when higher efficiency and lower drive complexity outweigh added component count and layout area
BU2520DX	BJT (1500 V, 2 A, TO-220); no integrated diode; slower t_f (~1.5 µs)	Suitable for higher-voltage magnetic ballasts but lacks integrated diode and speed for modern CFL EMI requirements	Select only for legacy magnetic ballast upgrades where voltage margin >700 V is mandatory and switching frequency <30 kHz

Compared with STB12NM60N and BU2520DX, STBV42D uniquely combines integrated diode, 0.3 µs switching, and TO-92 form factor - making it optimal for space-constrained, cost-sensitive CFL ballasts where drive simplicity and EMI control are prioritized over raw power handling.

Availability

STBV42D is available at Aetrix Electronics and suitable for compact fluorescent lamp (CFL) ballasts, electronic starter circuits, and small-signal high-voltage power supplies requiring stable component supply and long-term design continuity.

Supply support for STBV42D 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, discrete devices, and MEMS sensors for industrial, automotive, and consumer markets.

The STBV series targets cost-optimized, high-reliability power switching in lighting and auxiliary power applications, emphasizing ruggedness, parameter consistency, and integration of protection elements like freewheeling diodes.

FAQ

Is STBV42D still in active production?

No - STBV42D is marked as Obsolete in ST's official documentation (Doc ID 17236 Rev 2). Aetrix Electronics maintains limited legacy stock and supports design-in continuity through cross-reference guidance and alternative sourcing for qualified replacements meeting V_CEO, t_f, and TO-92 mechanical constraints.

Can STBV42D be used in automotive applications?

No - ST explicitly states in the datasheet that STBV42D is not recommended, authorized, or warranted for automotive, military, aircraft, life-saving, or safety-critical systems. Its qualification level is commercial-grade only, with no AEC-Q101 stress testing or automotive temperature range validation.

What is the role of the integrated diode in STBV42D?

The integrated diode serves as a monolithically fabricated freewheeling path across the collector-emitter terminals, enabling energy recirculation during inductive turn-off in CFL resonant tanks. It has V_F = 1.7 V at 350 mA and shares the same thermal junction as the transistor, ensuring matched temperature tracking and eliminating external diode placement errors.

How does STBV42D's RBSOA compare to standard TO-92 transistors?

STBV42D features enhanced RBSOA due to its cellular emitter and planar edge termination, allowing safe operation at 400 V and 1 A simultaneously - exceeding typical TO-92 BJT second-breakdown limits. This is validated by pulse-testing per IEC 60747-7, with no secondary breakdown observed up to 400 V/1 A at T_J = 150 °C.

STBV42D Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA)

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:: 1.5V @ 250mA, 750mA

Current - Collector Cutoff (Max):: 1mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 10 @ 400mA, 5V

Power - Max:: 1 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

STBV42D FAQ

1.How can I place an order for STBV42D through Aetrix?

Please submit a Request for Quotation (RFQ) for STBV42D 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 STBV42D reliable?

The price and inventory of STBV42D are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STBV42D is usually 5 days.

3.What payment methods are accepted for STBV42D?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STBV42D transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for STBV42D?

STBV42D orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your STBV42D 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 STBV42D?

For technical support, including STBV42D datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STBV42D requirements.

6.How does Aetrix verify that STBV42D is sourced from the original manufacturer or authorized distributors?

All STBV42D 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 STBV42D meets industry standards.

7.What is the process for return or replacement of STBV42D?

All STBV42D units undergo pre-shipment inspection (PSI). If there is an issue with STBV42D, 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 STBV42D part is unused and in its original packaging.

Return procedure for STBV42D:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…