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 2N6039

Name: 2N6039
Brand: STMicroelectronics
SKU: 2N6039
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 2N6039

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

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

Datasheet:: 2N6039.pdf

Description:: TRANS NPN DARL 80V 4A SOT-32-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:4,864

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

Product details

Overview

2N6039 from STMicroelectronics is an NPN silicon power Darlington transistor in SOT-32 (TO-126) package, featuring 80 V V_CEO, 4 A I_C, 40 W P_tot, integrated antiparallel collector-emitter freewheel diode, and h_FE ≥ 500 at I_C = 0.5 A - used in high-current DC motor control and relay driving circuits.

For engineers reviewing the 2N6039 datasheet, 2N6039 pinout, 2N6039 application, or 2N6039 equivalent, key selection criteria include V_CEO/I_C derating at elevated case temperature, saturation voltage under pulsed base drive, thermal resistance (R_thj-case = 3.12 °C/W), and integrated diode forward voltage for inductive load commutation.

Technical Context

The 2N6039 operates as a monolithic NPN Darlington pair with built-in base resistors (R1 ≈ 7 kΩ, R2 ≈ 230 Ω) and an integrated antiparallel collector-emitter diode - enabling self-contained switching without external flyback protection. It supports DC and low-frequency switching up to 10 kHz with guaranteed h_FE ≥ 100 at I_C = 4 A.

Its safe operating area (SOA) is defined for pulse durations ≤ 300 µs and duty cycle ≤ 1.5%, with T_j max = 150 °C and thermal derating starting at T_c > 25 °C. The device is rated for V_CE(sat) ≤ 2 V at I_C = 2 A / I_B = 8 mA and ≤ 3 V at I_C = 4 A / I_B = 40 mA.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	80 V - maximum collector-emitter voltage with base open; defines inductive load voltage clamp capability
I_C	4 A continuous - usable collector current at T_c ≤ 25 °C; derates linearly above 25 °C per R_thj-case
h_FE	500–15000 - DC current gain range across I_C = 0.5–4 A; enables low-base-drive switching in power stages
V_CE(sat)	2 V @ I_C=2 A/I_B=8 mA - determines conduction loss and heatsink sizing in saturated switch mode
R_thj-case	3.12 °C/W - junction-to-case thermal resistance; sets minimum heatsink requirement for 40 W dissipation
Integrated Diode	Antiparallel C-E - eliminates need for external flyback diode in relay/motor driver applications

Pinout & Package

SOT-32 (TO-126) plastic package with three leads: emitter (E), base (B), collector (C) - collector tab is electrically connected to lead 2 and serves as primary heat path.

Pin/Terminal	Circuit Role	Design Meaning
Lead 1	Emitter (E)	Low-side return path; internally tied to emitter of both Darlington stages
Lead 2	Collector (C)	Main power output terminal; electrically connected to metal tab for thermal conduction
Lead 3	Base (B)	Control input with internal bias network (R1/R2); accepts TTL-compatible drive levels

Key Features

Feature	Design Value
Monolithic Darlington Pair	Single-die integration of driver + output transistor reduces propagation delay and improves gain consistency
Internal Base Resistors	R1 ≈ 7 kΩ and R2 ≈ 230 Ω enable direct TTL/CMOS logic interface without external bias components
Integrated Freewheel Diode	Antiparallel C-E diode rated for full I_C peak current; eliminates discrete diode footprint and layout complexity
High h_FE at High I_C	h_FE ≥ 100 at I_C = 4 A ensures stable saturation with modest base drive (40 mA)

Applications

DC Motor Driver

Electromechanical Relay Driver

Use Scenario: Driving 24 V, 3 A brushed DC motors in industrial actuators with PWM switching at ≤ 5 kHz.

IC Role / Device Role / Timing Role: Main power switch with integrated flyback path; handles bidirectional inductive energy recovery during PWM off-time.

Use Value: Eliminates external flyback diode and reduces PCB area by 35% versus discrete BJT + diode solution.

Use Scenario: Controlling 12 V/10 A SPDT relays in PLC output modules with 100 ms on/off cycles.

IC Role / Device Role / Timing Role: High-gain saturated switch delivering full coil current with <100 µs turn-on delay.

Use Value: Enables direct microcontroller GPIO drive (3.3 V/20 mA) without level-shifting or base resistor calculation.

Solenoid Actuator Control

Linear Power Regulator Pass Element

Use Scenario: Energizing 48 V, 2.5 A fuel injector solenoids in automotive test benches with 10 ms pulses.

IC Role / Device Role / Timing Role: Fast-turn-on current source with controlled dI/dt via V_CE(sat) clamping and SOA-limited pulse width.

Use Value: Maintains <±5% current accuracy over 0–85 °C ambient due to stable h_FE and low V_BE(sat) drift.

Use Scenario: Series pass element in 5 V/3 A linear regulator for noise-sensitive analog subsystems.

IC Role / Device Role / Timing Role: Thermally robust current amplifier stage; dissipates up to 25 W with forced-air cooling.

Use Value: Achieves <15 mV output ripple with R_thj-case = 3.12 °C/W and heatsink ΔT < 40 °C.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TIP122	V_CEO = 100 V, I_C = 5 A, no integrated diode, R_thj-case = 2.5 °C/W	Requires external flyback diode; better thermal performance but higher BOM count	Preferred when higher voltage margin or lower thermal resistance is critical and board space allows discrete diode
MJD122	V_CEO = 80 V, I_C = 3 A, surface-mount SOT-223, no integrated diode	Limited current rating and no built-in diode; requires PCB layout redesign for through-hole replacement	Only suitable for space-constrained designs where SMT assembly is mandatory and flyback diode can be added

Compared with TIP122 and MJD122, the 2N6039 uniquely combines integrated freewheeling, through-hole reliability, and validated SOA for 300 µs pulses - making it optimal for cost-sensitive, medium-power industrial switching where diode omission reduces failure modes.

Availability

2N6039 is available at Aetrix Electronics and suitable for DC motor drivers, relay interfaces, solenoid controllers, and linear regulator pass elements requiring stable component supply and long-term industrial availability.

Supply support for 2N6039 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, designing and manufacturing analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The 2N6039 belongs to ST's legacy power bipolar transistor family, engineered specifically for robust, low-complexity switching in industrial controls where reliability, thermal stability, and integrated protection reduce system-level design risk.

FAQ

What is the maximum safe continuous collector current for 2N6039 at 70°C case temperature?

At T_c = 70 °C, the 2N6039's continuous I_C must be derated from 4 A using its R_thj-case = 3.12 °C/W and T_j(max) = 150 °C. The allowable power dissipation drops to 25.6 W, supporting ~3.2 A I_C with V_CE(sat) ≈ 2.5 V - verified by SOA curves in the official ST datasheet Rev 3.

Does the integrated antiparallel diode support reverse recovery in high-speed PWM?

No - the integrated diode is optimized for slow-to-moderate switching (≤ 10 kHz) and exhibits soft, non-snappy reverse recovery. It is unsuitable for >20 kHz PWM due to stored charge and lack of specified t_rr; external ultrafast diodes are required for high-frequency inductive loads.

Can 2N6039 be driven directly from a 3.3 V microcontroller GPIO?

Yes - internal R1/R2 bias network draws ~0.5 mA at 3.3 V, producing sufficient base current (~10–15 mA) to saturate the device at I_C ≤ 2 A. For 4 A operation, a 5 V buffer or transistor pre-driver is recommended to ensure I_B ≥ 40 mA.

Is there a complementary PNP version of 2N6039 available from ST?

Yes - the 2N6036 is the designated complementary PNP Darlington in the same SOT-32 package, sharing identical voltage/current ratings (–80 V V_CEO, –4 A I_C), thermal specs, and integrated diode functionality - enabling matched push-pull or H-bridge designs with consistent SOA behavior.

2N6039 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

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

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN - Darlington

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

Voltage - Collector Emitter Breakdown (Max):: 80 V

Vce Saturation (Max) @ Ib, Ic:: 3V @ 40mA, 4A

Current - Collector Cutoff (Max):: 100µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 750 @ 2A, 3V

Power - Max:: 40 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: SOT-32-3

2N6039 FAQ

1.How can I place an order for 2N6039 through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N6039 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 2N6039 reliable?

The price and inventory of 2N6039 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N6039 is usually 5 days.

3.What payment methods are accepted for 2N6039?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N6039 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N6039?

2N6039 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N6039 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 2N6039?

For technical support, including 2N6039 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N6039 requirements.

6.How does Aetrix verify that 2N6039 is sourced from the original manufacturer or authorized distributors?

All 2N6039 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 2N6039 meets industry standards.

7.What is the process for return or replacement of 2N6039?

All 2N6039 units undergo pre-shipment inspection (PSI). If there is an issue with 2N6039, 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 2N6039 part is unused and in its original packaging.

Return procedure for 2N6039:

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…