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

STMicroelectronics BD534

Name: BD534
Brand: STMicroelectronics
SKU: BD534
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BD534

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: BD534.pdf

Description:: TRANS PNP 45V 8A TO-220

Quantity:: RFQ Add To RFQ list

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Inventory:9,905

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Product details

Overview

BD534 from STMicroelectronics is a PNP complementary power transistor in TO-220 package, rated for V_CEO = –45 V, I_C = –8 A, and P_TOT = 50 W at T_case = 25°C. It delivers low V_CE(sat) = –0.8 V (IC = –2 A, IB = –0.2 A), high h_FE = 20–40 (IC = –10 mA, V_CE = –5 V), and operates up to T_J = 150°C. It is used in linear power supplies and audio output stages requiring robust complementary switching.

For engineers reviewing the BD534 datasheet, BD534 pinout, BD534 application, or BD534 equivalent, key selection criteria include its negative-polarity safe operating area, saturation voltage under high-current drive, DC current gain consistency across temperature, and compatibility with BD533/BD535 NPN counterparts in push-pull amplifier designs.

Technical Context

The BD534 is a planar silicon PNP bipolar junction transistor with "Base Island" layout, engineered for high DC current gain and low saturation voltage. Its complementary pairing with BD533 (NPN) enables symmetrical Class AB audio amplifiers and linear regulator pass elements.

It operates under strict polarity inversion: all voltage ratings (VCBO, VCES, VCEO) are negative; current ratings (IC, IB) are negative; and electrical characteristics like VBE and VCE(sat) are specified with reversed polarity conventions consistent with PNP operation.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	–45 V: Maximum reverse-biased collector-emitter voltage before breakdown; defines usable headroom in negative-rail linear regulators.
I_C	–8 A: Continuous collector current capability; supports high-power audio output or DC motor control loads.
P_TOT	50 W @ T_case = 25°C: Thermal dissipation limit; requires heatsink design for sustained >10 W operation.
V_CE(sat)	–0.8 V @ IC = –2 A, IB = –0.2 A: Low conduction loss in saturated switching; reduces heat generation in linear pass applications.
h_FE	20–40 @ IC = –10 mA, V_CE = –5 V: Stable DC current gain enabling predictable base drive sizing in amplifier bias networks.
T_J(max)	150°C: Maximum junction temperature; sets thermal derating slope (see Figure 3) for reliability above 25°C case temperature.

Pinout & Package

BD534 is housed in a standard TO-220 package with three leads: Collector (tab), Base (center), Emitter (right when tab faces outward). The metal tab is electrically connected to the collector and must be insulated if mounted to a grounded heatsink.

Pin/Terminal	Circuit Role	Design Meaning
Collector (Tab)	Main current sink terminal	Electrically tied to metal tab; requires isolation washer or mica pad when heatsink is grounded.
Base	Control input for minority-carrier injection	Receives negative base current to turn on; typical drive: –0.2 A for –2 A collector conduction.
Emitter	Current source terminal	Connected to negative supply rail in common-emitter configurations; carries full load current.

Key Features

Feature	Design Value
Planar "Base Island" structure	Enables uniform current distribution and stable h_FE across production lots and temperature range.
Low V_CE(sat) (–0.8 V)	Reduces power loss by >30% vs. legacy PNP transistors at 2 A, improving thermal margin in compact enclosures.
High h_FE (20–40)	Lowers required base drive current, easing design of discrete driver stages and reducing base resistor power dissipation.
TO-220 mechanical standardization	Ensures drop-in replacement compatibility with existing PCB footprints and heatsink mounting hardware.

Applications

Linear Power Supply Pass Element

Audio Output Stage

Use Scenario: Regulating unregulated negative DC rail (e.g., –48 V) to stable –15 V for op-amp biasing.

IC Role / Device Role / Timing Role: PNP series pass transistor operating in linear mode, dissipating excess voltage as heat.

Use Value: Low V_CE(sat) minimizes dropout voltage and improves efficiency; high h_FE simplifies base bias network design.

Use Scenario: Complementary push-pull output stage in 20 W audio amplifier driving 8 Ω speaker load.

IC Role / Device Role / Timing Role: Negative-rail output switch paired with BD533 NPN; handles negative half-cycle current delivery.

Use Value: Matched gain and saturation characteristics with BD533 reduce crossover distortion and improve THD performance.

DC Motor H-Bridge Low-Side Switch

Industrial Relay Driver

Use Scenario: Controlling direction and speed of 24 V DC brushed motor using four-transistor H-bridge topology.

IC Role / Device Role / Timing Role: PNP low-side switch in upper leg of H-bridge, sinking current during reverse drive phase.

Use Value: Robust SOA (Figure 2) supports pulsed 6 A loads without secondary breakdown; TO-220 tab enables direct heatsinking.

Use Scenario: Driving 12 V, 500 mA industrial relay coil from microcontroller GPIO via level-shifting transistor stage.

IC Role / Device Role / Timing Role: High-current PNP switch interfacing logic-level signal to inductive load.

Use Value: 1 A max base current rating allows direct drive from 74HC-series buffers; fast turn-off (Figure 15) suppresses relay contact arcing.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP power transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD44H11	V_CEO = –80 V, I_C = –8 A, h_FE = 30–120; higher voltage rating but wider h_FE spread.	Preferred in higher-voltage industrial controls (>60 V rails); less suitable for precision gain-matched pairs.	Select when extended breakdown margin is critical and gain matching with NPN counterpart is not required.
BD679	V_CEO = –80 V, I_C = –4 A, TO-126 package; lower current, smaller footprint, no metal tab.	Suitable for space-constrained low-power drivers; lacks TO-220 thermal mass for sustained >5 W dissipation.	Choose for board-area-limited designs where peak current ≤ 4 A and heatsinking is passive only.

Compared with MJD44H11 and BD679, BD534 offers tighter h_FE tolerance and proven complementary pairing with BD533, making it optimal for symmetric analog output stages-whereas MJD44H11 trades gain consistency for voltage headroom, and BD679 sacrifices thermal capacity for size reduction.

Availability

BD534 is available at Aetrix Electronics and suitable for linear power supplies, audio amplifiers, DC motor controllers, and industrial relay drivers requiring stable component supply and long-term obsolescence management.

Supply support for BD534 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 automotive, industrial, and consumer markets.

BD534 belongs to ST's legacy power bipolar transistor family, developed specifically for high-fidelity audio output stages and robust linear regulation where complementary NPN/PNP symmetry and thermal stability are essential.

FAQ

Is BD534 pin-compatible with BD533?

No-BD534 (PNP) and BD533 (NPN) share identical TO-220 pinout (C-B-E), but polarity reversal means they cannot be substituted without circuit redesign. Their complementary use requires mirrored biasing: BD534 emitter connects to negative rail, while BD533 emitter connects to ground or positive rail.

What is the safe operating area (SOA) limitation at 100°C case temperature?

Per Figure 2 and Figure 3, BD534's SOA derates linearly: at T_case = 100°C, maximum continuous I_C drops to ~4.5 A at V_CE = –20 V. Pulse operation (≤300 ms, duty ≤1.5%) extends limits per Figure 2's dashed curves.

Does BD534 support lead-free soldering?

Yes-BD534 is qualified as ECOPACK® with lead-free second-level interconnect. Per JEDEC JESD97, it supports reflow profiles up to 260°C peak, and the inner box label specifies maximum soldering temperature and time limits.

Can BD534 replace BD536 in a circuit?

Only if V_CEO ≥ –60 V is not required. BD536 has V_CEO = –60 V and identical package/pinout, but BD534's –45 V rating may cause premature breakdown in circuits with >45 V negative transients or inductive kickback.

BD534 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: PNP

Current - Collector (Ic) (Max):: 8 A

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 800mV @ 600mA, 6A

Current - Collector Cutoff (Max):: 100µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 25 @ 2A, 2V

Power - Max:: 50 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

BD534 FAQ

1.How can I place an order for BD534 through Aetrix?

Please submit a Request for Quotation (RFQ) for BD534 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 BD534 reliable?

The price and inventory of BD534 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BD534 is usually 5 days.

3.What payment methods are accepted for BD534?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BD534 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BD534?

BD534 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BD534 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 BD534?

For technical support, including BD534 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BD534 requirements.

6.How does Aetrix verify that BD534 is sourced from the original manufacturer or authorized distributors?

All BD534 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 BD534 meets industry standards.

7.What is the process for return or replacement of BD534?

All BD534 units undergo pre-shipment inspection (PSI). If there is an issue with BD534, 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 BD534 part is unused and in its original packaging.

Return procedure for BD534:

1.Submit a request within 90 days.

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

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