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 2N6668

Name: 2N6668
Brand: STMicroelectronics
SKU: 2N6668
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 2N6668

Manufacturer:: STMicroelectronics

Category:: Single Bipolar Transistors

Package:: TO-220-3

Datasheet:: 2N6668.pdf

Description:: TRANS PNP DARL 80V 10A TO-220

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:7,132

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

Product details

Overview

2N6668 from STMicroelectronics is a silicon PNP power Darlington transistor with integrated antiparallel collector-emitter diode, rated for 80 V V_CEO, 10 A I_C, and 65 W P_tot at T_c ≤ 25 °C, used in high-current switching and linear amplification circuits such as motor control drivers and industrial power supplies.

For engineers reviewing the 2N6668 datasheet, 2N6668 pinout, 2N6668 application, or 2N6668 equivalent, key selection criteria include guaranteed h_FE ≥ 1000 at 5 A, V_CE(sat) ≤ 2 V at I_C = 5 A / I_B = 10 mA, integrated flyback diode, TO-220 package thermal resistance (R_thj-case = 1.92 °C/W), and junction temperature limit of 150 °C.

Technical Context

This PNP Darlington combines two cascaded transistors (R1 ≈ 8 kΩ, R2 ≈ 120 Ω) to deliver high DC current gain (h_FE = 1000–20000) while maintaining low saturation voltage under heavy load. Its integrated antiparallel diode enables bidirectional current handling without external components in inductive load switching.

The device operates with negative polarity voltage/current conventions: V_CBO = –80 V, V_CEO = –80 V, I_C = –10 A. Pulse operation supports I_CM = –15 A with 300 µs pulse width and 1.5% duty cycle, enabling short-term surge capability beyond DC ratings.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	–80 V: Maximum reverse-biased collector-emitter voltage before breakdown; defines safe operating range in PNP switching applications.
I_C	–10 A: Continuous DC collector current; determines maximum steady-state load drive capability in power stages.
P_tot	65 W at T_c ≤ 25 °C: Total power dissipation limit; requires heatsinking to maintain junction temperature ≤ 150 °C.
h_FE	1000–20000 at I_C = 5 A / V_CE = 3 V: High DC current gain reduces required base drive current, easing driver design.
V_CE(sat)	–2 V at I_C = –5 A / I_B = –10 mA: Low saturation voltage minimizes conduction loss and heat generation during on-state.
R_thj-case	1.92 °C/W: Junction-to-case thermal resistance; enables calculation of heatsink requirements for thermal management.

Pinout & Package

Package: TO-220 (3-lead, straight lead, insulated tab). Mounting surface is electrically isolated from collector terminal. Standard mechanical dimensions per STMicroelectronics drawing P011C.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Emitter terminal of PNP Darlington pair	Connected to positive rail in high-side switch configurations; carries full load current.
2 (Base)	Control input for Darlington pair	Drives internal R1–R2 bias network; requires ~10 mA for full turn-on at 5 A load.
3 (Collector)	Collector terminal of PNP Darlington pair	Connected to load return path; internally tied to antiparallel diode anode for inductive kickback protection.

Key Features

Feature	Design Value
Integrated antiparallel diode	Eliminates need for external flyback diode in relay/motor driver circuits, reducing BOM count and PCB area.
High h_FE (≥1000)	Reduces base drive current requirement by >10× versus single PNP, simplifying gate/driver IC selection.
Low V_CE(sat) (≤2 V @ 5 A)	Limits conduction loss to ≤10 W at 5 A, improving efficiency and easing thermal design in continuous-duty applications.
TO-220 package with insulated tab	Enables direct mounting to heatsink without electrical isolation hardware, lowering assembly cost and thermal interface resistance.

Applications

Motor Control Driver

Relay Driver Circuit

Use Scenario: Driving 24 V DC brushed motors in industrial actuators with PWM switching up to 20 kHz.

IC Role / Device Role / Timing Role: High-side PNP Darlington switch controlling motor current path to ground.

Use Value: Integrated antiparallel diode clamps inductive flyback, eliminating external diode and reducing component count by one.

Use Scenario: Controlling 120 V AC solenoid relays via microcontroller GPIO through optocoupler-isolated base drive.

IC Role / Device Role / Timing Role: General-purpose power switch providing galvanically isolated load switching with fast turn-off.

Use Value: Guaranteed h_FE ≥ 1000 ensures reliable turn-on with ≤10 mA base current, compatible with standard logic-level drivers.

Linear Power Regulator

DC-DC Converter Output Stage

Use Scenario: Pass element in adjustable 5–30 V, 5 A linear regulator for lab bench power supply.

IC Role / Device Role / Timing Role: Series pass transistor dissipating variable power based on output load and dropout voltage.

Use Value: R_thj-case = 1.92 °C/W allows stable operation at 65 W with moderate heatsinking, supporting wide input-output differentials.

Use Scenario: Synchronous rectifier replacement in non-isolated buck converter output stage operating at 100 kHz.

IC Role / Device Role / Timing Role: Low-saturation PNP switch replacing Schottky diode to reduce conduction loss.

Use Value: V_CE(sat) ≤ 2 V at 5 A cuts forward drop by >0.3 V versus typical 45 V Schottky, improving efficiency by ~2% at full load.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD6227G	Higher V_CEO (–100 V), lower h_FE (min 750), TO-263 package	Preferred for higher-voltage industrial systems requiring >80 V blocking; surface-mount only	Select when board space constraints favor SMT or system voltage exceeds 80 V.
TIP127	Same V_CEO (–80 V), lower I_C (–5 A), no integrated diode, TO-220	Requires external flyback diode; suitable for cost-sensitive designs where diode integration is not critical	Choose when thermal budget allows lower current rating and BOM flexibility justifies added component.

Compared with MJD6227G and TIP127, the 2N6668 uniquely balances 10 A current capability, integrated diode, and through-hole TO-220 packaging-making it optimal for medium-power, serviceable, and thermally demanding industrial switching where reliability and repairability matter.

Availability

2N6668 is available at Aetrix Electronics and suitable for motor control drivers, relay driver circuits, linear power regulators, and DC-DC converter output stages requiring stable component supply across production lifecycles.

Supply support for 2N6668 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 2N6668 belongs to ST's legacy power bipolar transistor family, engineered specifically for robust, high-current linear and switching applications in industrial controls and power conversion where reliability under thermal stress is critical.

FAQ

Is the 2N6668 pin-compatible with the TIP127?

No. While both are PNP Darlington transistors in TO-220 packages, the 2N6668 has emitter-base-collector pinout (E-B-C), whereas the TIP127 uses emitter-collector-base (E-C-B). Swapping them without verifying pin assignment will cause circuit failure or device damage.

Does the integrated antiparallel diode support bidirectional current flow?

Yes-the internal diode connects anode to collector and cathode to emitter, allowing reverse current from emitter to collector during inductive flyback. It is rated for the same peak current (15 A) and junction temperature (150 °C) as the transistor itself.

What is the minimum base current needed to saturate the 2N6668 at 10 A collector current?

Per datasheet, V_CE(sat) = –3 V is specified at I_C = –10 A and I_B = –0.1 A. Therefore, 100 mA base current is required for guaranteed saturation at full rated current; design margin suggests using ≥120 mA for reliability across temperature.

Can the 2N6668 be used in parallel for higher current handling?

Not recommended without individual emitter resistors. The 2N6668 exhibits positive thermal feedback due to its Darlington structure, causing current hogging if paralleled directly. If required, use matched units with 0.1–0.22 Ω emitter ballast resistors and shared heatsinking.

2N6668 Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: PNP - Darlington

Current - Collector (Ic) (Max):: 10 A

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

Vce Saturation (Max) @ Ib, Ic:: 3V @ 100mA, 10A

Current - Collector Cutoff (Max):: 1mA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 1000 @ 5A, 3V

Power - Max:: 65 W

Frequency - Transition:: -

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

2N6668 FAQ

1.How can I place an order for 2N6668 through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N6668 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 2N6668 reliable?

The price and inventory of 2N6668 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N6668 is usually 5 days.

3.What payment methods are accepted for 2N6668?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N6668 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N6668?

2N6668 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N6668 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 2N6668?

For technical support, including 2N6668 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N6668 requirements.

6.How does Aetrix verify that 2N6668 is sourced from the original manufacturer or authorized distributors?

All 2N6668 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 2N6668 meets industry standards.

7.What is the process for return or replacement of 2N6668?

All 2N6668 units undergo pre-shipment inspection (PSI). If there is an issue with 2N6668, 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 2N6668 part is unused and in its original packaging.

Return procedure for 2N6668:

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…