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

STMicroelectronics BD682

Name: BD682
Brand: STMicroelectronics
SKU: BD682
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BD682

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

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

Datasheet:: BD682.pdf

Description:: TRANS PNP DARL 100V 4A SOT-32-3

Quantity:: RFQ Add To RFQ list

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Inventory:2,852

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Product details

Overview

BD682 from STMicroelectronics is a PNP complementary power Darlington transistor in SOT-32 (TO-126) package, rated for V_CEO = −100 V, I_C = −4 A, and P_TOT = 40 W at T_case = 25°C, featuring monolithic Darlington configuration with integrated antiparallel collector-emitter diode for robust switching in industrial linear amplifiers and motor control stages.

For engineers reviewing the BD682 datasheet, BD682 pinout, BD682 application, or BD682 equivalent, this page delivers verified electrical specs (h_FE ≥ 750 at I_C = −1.5 A, V_CE(sat) = −2.5 V), thermal limits (T_J(max) = 150°C), package dimensions (SOT-32), and real-world alternatives for high-current PNP Darlington replacement in legacy industrial power stages.

Technical Context

The BD682 implements a monolithic planar-base Darlington pair with integrated antiparallel C–E diode to suppress inductive kickback during turn-off. Its high DC current gain (h_FE ≥ 750) enables low base drive requirements while maintaining stable operation up to 150°C junction temperature.

Designed for linear and switching use, it supports pulsed collector currents up to −6 A (I_CM) and exhibits V_CEO(sus) = −100 V under sustained 50 mA load-critical for reliable operation in unregulated DC bus and relay driver circuits without external snubbers.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	−100 V: Maximum sustainable collector-emitter voltage with base open, defining safe operating area in high-voltage industrial supplies.
I_C	−4 A continuous: Rated DC collector current at T_case = 25°C, enabling direct drive of solenoids and small motors.
P_TOT	40 W at T_case = 25°C: Total power dissipation limit requiring heatsinking for >1.5 A steady-state loads.
h_FE	≥750 at I_C = −1.5 A, V_CE = −3 V: High current gain reduces required base drive current to ≤2 mA for full conduction.
V_CE(sat)	−2.5 V at I_C = −1.5 A, I_B = −30 mA: Low saturation voltage minimizes conduction loss in linear regulators and H-bridge low-side switches.
f_T	High frequency: Enables usable bandwidth beyond 100 kHz in analog amplifier stages and PWM-driven loads.
T_J(max)	150°C: Maximum junction temperature allowing operation in enclosed industrial enclosures without forced air cooling.

Pinout & Package

SOT-32 (TO-126) package: Three-terminal through-hole plastic case with emitter tab (pin 1), base (pin 2), and collector (pin 3) - collector internally connected to metal tab for thermal and electrical grounding.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Emitting terminal of PNP Darlington pair	Connected to positive rail in high-side switch configurations; requires low-impedance return path for stable biasing.
2 (Base)	Control input for Darlington pair	Driven by TTL/CMOS logic via current-limiting resistor; internal R1 = 15 kΩ and R2 = 100 Ω provide built-in bias network.
3 (Collector)	Main output terminal, tied to metal tab	Electrically and thermally coupled to heatsink; must be isolated from chassis unless circuit ground reference permits.

Key Features

Feature	Design Value
Monolithic Darlington + antiparallel C–E diode	Eliminates need for external flyback diode in inductive load switching, reducing BOM count and PCB footprint.
Good h_FE linearity	Ensures predictable gain across I_C range (0.1–3 A), critical for analog current sources and linear regulator pass elements.
Planar base island technology	Improves thermal stability and ruggedness versus epitaxial base processes, supporting repeated surge current events.
ECOPACK® lead-free packaging	Complies with RoHS Directive 2011/65/EU and JEDEC JESD97 marking standards for industrial environmental compliance.

Applications

Industrial Linear Amplifiers

DC Motor Direction Control

Use Scenario: High-fidelity audio output stage or precision current source in programmable DC power supplies.

IC Role / Device Role / Timing Role: PNP Darlington pass element delivering regulated output current with minimal base drive overhead.

Use Value: h_FE ≥ 750 allows microcontroller GPIOs to directly drive the base, eliminating discrete driver transistors and reducing component count.

Use Scenario: Low-side switch in bidirectional H-bridge for 24–48 V brushed DC motors in factory automation.

IC Role / Device Role / Timing Role: Complementary PNP switch paired with NPN BD681 to form high-current half-bridge leg.

Use Value: Integrated antiparallel diode clamps inductive back-EMF during PWM off-time, preventing voltage spikes >100 V.

Relay and Solenoid Drivers

Unregulated HV Power Switching

Use Scenario: Driving 12–48 V DC relays and pneumatic solenoids in PLC output modules.

IC Role / Device Role / Timing Role: High-gain saturated switch turning on/off inductive loads with <10 µs rise/fall times.

Use Value: V_CEO(sus) = −100 V ensures reliable operation even with 80 V transient surges common in industrial 48 V systems.

Use Scenario: Main switching element in non-isolated buck-derived converters or battery disconnect circuits.

IC Role / Device Role / Timing Role: High-current PNP switch handling up to −4 A continuous load in unregulated DC bus applications.

Use Value: 40 W power rating at T_case = 25°C enables operation with modest heatsinking (e.g., 2°C/W) at full rated current.

Equivalent & Alternatives

The following parts are listed as comparable options for similar PNP Darlington switching applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD682	Same V_CEO (−100 V), lower h_FE (min. 500), TO-252 surface-mount package	Requires PCB redesign for SMT assembly; reduced gain demands higher base drive current.	Preferred for new SMT designs where board space and automated assembly outweigh legacy through-hole compatibility.
BD682A	Higher V_CEO(sus) (−100 V), identical pinout, but h_FE tested at I_C = −2 A (vs. −1.5 A) and V_CE(sat) = −2.8 V	Marginally higher saturation loss; optimized for higher-current pulse operation.	Select when operating near I_C = −2 A with tighter thermal constraints and verified base drive capability.

Compared with MJD682 and BD682A, the BD682 offers superior h_FE linearity at mid-range currents and proven reliability in legacy through-hole industrial boards, making it optimal for repair, replacement, and cost-sensitive through-hole production.

Availability

BD682 is available at Aetrix Electronics and suitable for industrial linear amplifiers, DC motor direction control, relay/solenoid drivers, and unregulated HV power switching requiring stable component supply across long-lifecycle equipment programs.

Supply support for BD682 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, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The BD6xxx series belongs to ST's legacy power bipolar portfolio, engineered specifically for high-reliability linear and switching power control in industrial equipment where ruggedness, thermal stability, and long-term availability are mandatory.

FAQ

Is BD682 pin-compatible with BD680 or BD678?

Yes - all BD6xxx PNP devices (BD678, BD678A, BD680, BD680A, BD682, BD682A) share identical SOT-32 pinout (Emitter–Base–Collector). However, V_CEO ratings differ: BD678/BD678A = −60 V, BD680/BD680A = −80 V, BD682/BD682A = −100 V. Substitution requires verifying voltage margin in the target circuit.

Does BD682 require an external flyback diode when driving inductive loads?

No - BD682 integrates a monolithic antiparallel collector-emitter diode, explicitly designed to clamp inductive kickback during turn-off. This eliminates the need for an external diode in most relay, solenoid, and motor applications, provided peak reverse voltage stays within V_CEO rating.

What is the maximum safe continuous collector current at 70°C case temperature?

Derating from 40 W at 25°C case temperature yields ~28 W at 70°C case (using typical thermal resistance R_θJC ≈ 0.625°C/W). At V_CE(sat) = −2.5 V, this supports ~11.2 A·V → ~4.5 A theoretical, but datasheet limits I_C to −4 A regardless of temperature. Therefore, −4 A remains the absolute max continuous current at any case temperature.

Can BD682 be used in parallel with another BD682 for higher current?

Not recommended without individual emitter resistors. Darlington transistors exhibit positive thermal feedback; mismatched h_FE or thermal coupling causes current hogging. If paralleling is essential, use 0.1–0.22 Ω emitter ballast resistors per device and ensure matched mounting on a common heatsink with uniform thermal interface.

BD682 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

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

Packaging:: Tube

Product Status:: Active

Transistor Type:: PNP - Darlington

Current - Collector (Ic) (Max):: 4 A

Voltage - Collector Emitter Breakdown (Max):: 100 V

Vce Saturation (Max) @ Ib, Ic:: 2.5V @ 30mA, 1.5A

Current - Collector Cutoff (Max):: 500µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 750 @ 1.5A, 3V

Power - Max:: 40 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: SOT-32-3

BD682 FAQ

1.How can I place an order for BD682 through Aetrix?

Please submit a Request for Quotation (RFQ) for BD682 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 BD682 reliable?

The price and inventory of BD682 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BD682 is usually 5 days.

3.What payment methods are accepted for BD682?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BD682 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BD682?

BD682 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BD682 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 BD682?

For technical support, including BD682 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BD682 requirements.

6.How does Aetrix verify that BD682 is sourced from the original manufacturer or authorized distributors?

All BD682 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 BD682 meets industry standards.

7.What is the process for return or replacement of BD682?

All BD682 units undergo pre-shipment inspection (PSI). If there is an issue with BD682, 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 BD682 part is unused and in its original packaging.

Return procedure for BD682:

1.Submit a request within 90 days.

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

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