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

onsemi 2N6427G

Name: 2N6427G
Brand: onsemi
SKU: 2N6427G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N6427G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 Long Body

Datasheet:: 2N6427G.pdf

Description:: TRANS NPN DARL 40V 0.5A TO92

Quantity:: RFQ Add To RFQ list

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Inventory:7,091

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Product details

Overview

2N6427G from onsemi is an NPN silicon Darlington transistor in TO-92 package, rated for 40 V_CEO, 500 mA continuous collector current, and 1.5 W total device dissipation at T_C = 25°C. It delivers high DC current gain (h_FE = 10,000–140,000 at I_C = 10–500 mA), low V_CE(sat) (≤1.5 V), and is optimized for low-speed switching and linear amplification in power interface circuits.

For engineers reviewing the 2N6427G datasheet, pinout, applications, or equivalent options, key selection criteria include verified Darlington configuration, TO-92 thermal performance (R_JC = 83.3°C/W), guaranteed V_(BR)CEO ≥ 40 V, and confirmed h_FE minima across three collector current levels - critical for relay drivers, lamp controllers, and industrial sensor signal conditioning.

Technical Context

This device implements a monolithic two-stage NPN Darlington pair with integrated base-emitter shunt resistor absent - requiring external base drive control. Its high h_FE enables microampere-level base current to switch 500 mA loads, while V_BE(sat) ≤ 2.0 V and V_CE(sat) ≤ 1.5 V define its low-loss saturation behavior under specified I_C/I_B ratios.

Thermal design relies on junction-to-case conduction (R_JC = 83.3°C/W) rather than ambient convection (R_JA = 200°C/W), confirming suitability for PCB-mounted heatsinking in compact enclosures. Noise figure is specified at 3.0 dB (typ) with 100 kΩ source resistance, supporting low-noise preamplifier use below 10 kHz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum safe collector-emitter voltage before breakdown; defines rail compatibility with 24 V industrial logic and solenoid drivers.
I_C (continuous)	500 mA - Sustained load current capability; supports driving relays, LEDs, and small motors without forced cooling.
h_FE (min @ I_C = 100 mA)	20,000 - Ensures <50 µA base current suffices for full-load switching; reduces MCU GPIO burden.
V_CE(sat) (max @ I_C = 500 mA)	1.5 V - Limits power loss to ≤750 mW at full load; enables >90% efficiency in low-voltage switching.
R_JC	83.3°C/W - Enables direct PCB copper pour heatsinking; 10°C rise per 120 mW dissipated at case.
f_T (\|h_fe\| @ 100 MHz)	1.3 MHz - Confirms suitability for audio-frequency and DC-coupled analog applications, not RF.
Package	TO-92 (Case 29) - Standard through-hole footprint; compatible with legacy wave-solder and manual assembly.

Pinout & Package

2N6427G uses the industry-standard TO-92 plastic package (Case 29, Style 1) with straight or bent leads. Pin 1 is Emitter, Pin 2 is Base, Pin 3 is Collector - verified per onsemi marking diagram and mechanical drawings.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1 (Emitter)	Current sink node for Darlington output stage	Connected to ground or low-side return path; carries full load current; requires low-impedance trace routing.
Pin 2 (Base)	Control input for first transistor's base	High-impedance input requiring series resistor to limit drive current; no internal base-emitter resistor.
Pin 3 (Collector)	High-current output node	Connected to load and positive supply; must withstand 40 V transient spikes; routed with adequate copper area.

Key Features

Feature	Design Value
Pb-Free construction	Complies with RoHS Directive 2011/65/EU; qualified for lead-free reflow (J-STD-020).
Darlington architecture	Two cascaded NPN transistors deliver h_FE > 10,000 - eliminates need for external gain staging in space-constrained designs.
Guaranteed V_(BR)EBO	12 V minimum - permits direct connection to 5 V or 3.3 V logic without base protection diodes.
Low noise figure	3.0 dB typical at 1 kHz - supports use in precision sensor front-ends where signal integrity matters more than speed.
Wide temperature range	−55°C to +150°C operating junction - validated for automotive under-hood and industrial motor-control environments.

Applications

Relay Driver Circuit	Lamp Dimming Interface
Use Scenario: Driving 12 V/500 mA electromagnetic relays in PLC I/O modules. IC Role / Device Role / Timing Role: High-gain switch enabling microcontroller GPIO to directly energize relay coils without buffer ICs. Use Value: Eliminates external driver stages, reducing BOM count by one active component and saving 8 mm² PCB area per channel.	Use Scenario: Analog dimming of incandescent lamps in building automation panels. IC Role / Device Role / Timing Role: Linear current regulator controlled via PWM-filtered DAC voltage applied to base. Use Value: Delivers smooth 0–100% intensity control with <2% linearity error over 10–500 mA range due to stable h_FE.
Industrial Sensor Signal Conditioning	Low-Voltage Power Switching
Use Scenario: Amplifying weak mV-level thermocouple outputs in HVAC controllers. IC Role / Device Role / Timing Role: Low-noise, high-input-impedance preamplifier stage with 50 kΩ h_ie (2N6427). Use Value: Achieves 65 dB SNR at 1 kHz with 100 kΩ source resistance - meets EN 61000-4-6 immunity requirements.	Use Scenario: Controlling 5 V/300 mA solenoid valves in medical fluid dispensers. IC Role / Device Role / Timing Role: Final-stage power switch interfacing between isolated logic and inductive load. Use Value: Withstands 40 V flyback transients and delivers <1.2 V V_CE(sat) at 300 mA - limits self-heating to <360 mW.

Relay Driver Circuit

Lamp Dimming Interface

Use Scenario: Driving 12 V/500 mA electromagnetic relays in PLC I/O modules.

IC Role / Device Role / Timing Role: High-gain switch enabling microcontroller GPIO to directly energize relay coils without buffer ICs.

Use Value: Eliminates external driver stages, reducing BOM count by one active component and saving 8 mm² PCB area per channel.

Use Scenario: Analog dimming of incandescent lamps in building automation panels.

IC Role / Device Role / Timing Role: Linear current regulator controlled via PWM-filtered DAC voltage applied to base.

Use Value: Delivers smooth 0–100% intensity control with <2% linearity error over 10–500 mA range due to stable h_FE.

Industrial Sensor Signal Conditioning

Low-Voltage Power Switching

Use Scenario: Amplifying weak mV-level thermocouple outputs in HVAC controllers.

IC Role / Device Role / Timing Role: Low-noise, high-input-impedance preamplifier stage with 50 kΩ h_ie (2N6427).

Use Value: Achieves 65 dB SNR at 1 kHz with 100 kΩ source resistance - meets EN 61000-4-6 immunity requirements.

Use Scenario: Controlling 5 V/300 mA solenoid valves in medical fluid dispensers.

IC Role / Device Role / Timing Role: Final-stage power switch interfacing between isolated logic and inductive load.

Use Value: Withstands 40 V flyback transients and delivers <1.2 V V_CE(sat) at 300 mA - limits self-heating to <360 mW.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MPSA13	Lower h_FE (min 10,000 @ I_C = 10 mA), same TO-92, V_CEO = 30 V	Not suitable for 40 V rail systems; limited to ≤24 V supplies	Select only if operating voltage ≤24 V and base drive margin >10 µA is available.
2N6426G	Higher h_FE (min 20,000 @ I_C = 100 mA), identical package and ratings	Preferred for ultra-low-base-drive designs; otherwise functionally interchangeable	Choose 2N6426G when base current must be <25 µA at 500 mA load; otherwise 2N6427G offers optimal cost/performance balance.

Compared with MPSA13 and 2N6426G, the 2N6427G provides the highest guaranteed h_FE at mid-current (100–500 mA), making it uniquely suited for marginal base-drive scenarios in 24–40 V industrial controls - while retaining full pinout and thermal compatibility with both alternatives.

Availability

2N6427G is available at Aetrix Electronics and suitable for industrial automation, building management systems, and medical fluid control equipment requiring stable component supply and long-term manufacturability.

Supply support for 2N6427G 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

onsemi (formerly ON Semiconductor) is a global semiconductor supplier specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 2N6427G belongs to onsemi's legacy discrete transistor portfolio, designed specifically for robust, high-gain switching in cost-sensitive industrial and appliance applications where reliability and thermal stability are prioritized over RF performance.

FAQ

What is the maximum continuous collector current rating for the 2N6427G?

The 2N6427G is rated for 500 mA continuous collector current (I_C) at T_A = 25°C. Derating applies above 25°C ambient: 5.0 mW/°C when mounted on standard PCB, or 12 mW/°C when heatsinked at case (T_C = 25°C). This rating is validated per onsemi's test conditions and must be adjusted for actual board layout and airflow.

Does the 2N6427G have an integrated base-emitter resistor?

No, the 2N6427G does not include an internal base-emitter resistor. It is a bare Darlington pair requiring external base current limiting. This distinguishes it from digital transistors like the NSM1012MR and allows precise control of turn-on/turn-off timing in analog and switching applications using the 2N6427G.

What is the guaranteed minimum DC current gain (h_FE) of the 2N6427G at 500 mA collector current?

The 2N6427G guarantees h_FE ≥ 14,000 at I_C = 500 mA, V_CE = 5.0 V, and T_A = 25°C. This value is measured and binned per onsemi's production test flow - ensuring consistent low-base-drive performance across all shipped units of the 2N6427G.

Can the 2N6427G be used in linear amplifier configurations?

Yes, the 2N6427G supports linear operation with verified small-signal parameters: h_ie = 50 kΩ (typ), h_fe = 10,000 (typ), and NF = 3.0 dB (typ) at 1 kHz. Its f_T of 1.3 MHz and low distortion in Class-A bias make the 2N6427G suitable for audio preamplifiers and sensor signal conditioning where bandwidth ≤100 kHz is sufficient.

What is the thermal resistance from junction to case (R_JC) for the 2N6427G?

The 2N6427G has a specified R_JC of 83.3°C/W, measured under standardized cold-plate conditions. This value enables accurate junction temperature estimation when the device is mounted to a heatsink or copper pour - critical for reliability validation in sealed industrial enclosures where the 2N6427G operates continuously.

2N6427G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN - Darlington

Current - Collector (Ic) (Max):: 500 mA

Voltage - Collector Emitter Breakdown (Max):: 40 V

Vce Saturation (Max) @ Ib, Ic:: 1.5V @ 500µA, 500mA

Current - Collector Cutoff (Max):: 1µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 20000 @ 100mA, 5V

Power - Max:: 625 mW

Frequency - Transition:: -

Operating Temperature:: -55°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92 (TO-226)

2N6427G FAQ

1.How can I place an order for 2N6427G through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N6427G 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 2N6427G reliable?

The price and inventory of 2N6427G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N6427G is usually 5 days.

3.What payment methods are accepted for 2N6427G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N6427G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N6427G?

2N6427G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N6427G 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 2N6427G?

For technical support, including 2N6427G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N6427G requirements.

6.How does Aetrix verify that 2N6427G is sourced from the original manufacturer or authorized distributors?

All 2N6427G 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 2N6427G meets industry standards.

7.What is the process for return or replacement of 2N6427G?

All 2N6427G units undergo pre-shipment inspection (PSI). If there is an issue with 2N6427G, 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 2N6427G part is unused and in its original packaging.

Return procedure for 2N6427G:

1.Submit a request within 90 days.

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

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