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

onsemi 2N5655G

Name: 2N5655G
Brand: onsemi
SKU: 2N5655G
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N5655G

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N5655G.pdf

Description:: TRANS NPN 250V 0.5A TO-126

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2N5655G from onsemi is a plastic NPN silicon high-voltage power transistor rated for 250 V_CEO, 0.5 A continuous collector current, and 20 W total device dissipation at T_C = 25°C. It features excellent DC current gain (h_FE ≥ 25 at I_C = 50 mA), high f_T of 10 MHz, and RoHS-compliant Pb-free TO-225 packaging. It is designed for line-operated audio output amplifiers, low-current high-voltage converters, and AC line relays.

For engineers reviewing the 2N5655G datasheet, pinout, applications, or equivalent options, key selection considerations include its 250 V_CEO rating, thermal resistance of 6.25°C/W (junction-to-case), safe operating area limits under inductive switching, DC current gain variation across temperature, and compatibility with standard TO-225 mounting and drive requirements.

Technical Context

The 2N5655G operates as a medium-power NPN bipolar junction transistor optimized for high-voltage switching and linear amplification in line-powered systems. Its sustaining voltage (V_CEO(sus)) is specified at 250 V under inductive load conditions (I_C = 100 mA, L = 50 mH), and it supports peak collector current up to 1.0 A with base current limiting to 1.0 A.

Thermal design is constrained by R_JC = 6.25°C/W and a maximum junction temperature of +150°C; derating begins above 25°C at 0.16 W/°C. Safe operating area (SOA) curves define simultaneous V_CE–I_C limits governed by both thermal and second-breakdown boundaries, with distinct limits for DC, pulsed, and inductive loads.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	250 V - Maximum collector-emitter voltage before breakdown under specified test conditions; defines upper voltage limit for DC and pulse operation.
I_C (continuous)	0.5 A - Continuous collector current rating; sets steady-state power handling capability with appropriate heatsinking.
P_D @ T_C = 25°C	20 W - Total device power dissipation limit at case temperature of 25°C; requires thermal management for higher ambient or case temperatures.
h_FE (min)	25 - Minimum DC current gain at I_C = 50 mA, V_CE = 10 V; determines required base drive for saturation or linear biasing.
f_T	10 MHz - Current-gain-bandwidth product; indicates usable frequency range for small-signal amplification or switching speed potential.
R_JC	6.25 °C/W - Junction-to-case thermal resistance; directly impacts heatsink sizing and maximum allowable power at given case temperature.
V_CE(sat)	1.0 V (max at I_C/I_B = 10) - Collector-emitter saturation voltage; determines conduction loss and power dissipation in switching applications.

Pinout & Package

2N5655G is housed in a TO-225 package (Case 77-09, Style 1), a 4-pin plastic power transistor outline with collector-connected tab (pin 2 and pin 4). The package provides mechanical robustness and thermal path via the backside collector tab, suitable for through-hole mounting and moderate-power dissipation.

Pin/Terminal	Circuit Role	Design Meaning
Pin 1	Emitter	Main current exit terminal; referenced for base drive and used in common-emitter configurations.
Pins 2 & 4	Collector	Electrically connected collector terminals; pins 2 and 4 plus backside metal tab form a single collector node for enhanced thermal and current handling.
Pin 3	Base	Control terminal for bipolar current amplification; requires current-limited drive to achieve target I_C and avoid overdrive or thermal runaway.

Key Features

Feature	Design Value
High V_CEO rating	250 V enables direct use in 120/230 VAC line-referenced circuits without intermediate step-down, reducing component count in relay drivers and HV converters.
RoHS-compliant Pb-free construction	G suffix confirms lead-free termination and compliant materials per EU Directive 2011/65/EU, supporting environmentally regulated industrial and consumer production.
High h_FE × f_T product	DC gain ≥25 and f_T = 10 MHz support stable linear amplification and fast switching in audio and SMPS auxiliary stages.
Defined SOA with second-breakdown limits	Published active-region safe operating area curves allow reliable design of inductive-switching circuits (e.g., relay coils, flyback snubbers) without destructive failure.

Applications

Audio Output Amplifier Stage	Low-Current HV DC-DC Converter
Use Scenario: Driving 8 Ω speaker loads in Class-B or Class-AB line-powered audio amplifiers requiring >200 V headroom. IC Role / Device Role / Timing Role: Power output transistor in common-emitter configuration delivering amplified audio signal to load. Use Value: 250 V_CEO and 20 W dissipation enable full-swing operation into reactive loads without clipping or breakdown under transient peaks.	Use Scenario: Switching element in flyback or forward converter auxiliary windings generating isolated bias rails for gate drivers or controllers. IC Role / Device Role / Timing Role: High-voltage switch controlling energy transfer from primary to auxiliary winding during off-time. Use Value: Sustaining voltage rating of 250 V_CEO(sus) ensures reliable operation under inductive turn-off stress with 50 mH load and 100 mA current.
AC Line Relay Driver	Industrial Control Interface
Use Scenario: Directly energizing 120/240 VAC coil relays in programmable logic controller (PLC) output modules. IC Role / Device Role / Timing Role: High-voltage interface transistor isolating low-voltage logic from mains-referenced relay coil. Use Value: 250 V_CEO and 1.0 A peak current rating accommodate relay coil inrush and contact arcing transients without secondary breakdown.	Use Scenario: Level-shifting and isolation stage in industrial sensor interface circuits interfacing microcontrollers to 24 VDC or 120 VAC field devices. IC Role / Device Role / Timing Role: Signal-level translator and current amplifier between MCU GPIO and higher-voltage actuator control lines. Use Value: High h_FE (≥25) allows direct GPIO drive with minimal external components while maintaining noise immunity and load drive margin.

Audio Output Amplifier Stage

Low-Current HV DC-DC Converter

Use Scenario: Driving 8 Ω speaker loads in Class-B or Class-AB line-powered audio amplifiers requiring >200 V headroom.

IC Role / Device Role / Timing Role: Power output transistor in common-emitter configuration delivering amplified audio signal to load.

Use Value: 250 V_CEO and 20 W dissipation enable full-swing operation into reactive loads without clipping or breakdown under transient peaks.

Use Scenario: Switching element in flyback or forward converter auxiliary windings generating isolated bias rails for gate drivers or controllers.

IC Role / Device Role / Timing Role: High-voltage switch controlling energy transfer from primary to auxiliary winding during off-time.

Use Value: Sustaining voltage rating of 250 V_CEO(sus) ensures reliable operation under inductive turn-off stress with 50 mH load and 100 mA current.

AC Line Relay Driver

Industrial Control Interface

Use Scenario: Directly energizing 120/240 VAC coil relays in programmable logic controller (PLC) output modules.

IC Role / Device Role / Timing Role: High-voltage interface transistor isolating low-voltage logic from mains-referenced relay coil.

Use Value: 250 V_CEO and 1.0 A peak current rating accommodate relay coil inrush and contact arcing transients without secondary breakdown.

Use Scenario: Level-shifting and isolation stage in industrial sensor interface circuits interfacing microcontrollers to 24 VDC or 120 VAC field devices.

IC Role / Device Role / Timing Role: Signal-level translator and current amplifier between MCU GPIO and higher-voltage actuator control lines.

Use Value: High h_FE (≥25) allows direct GPIO drive with minimal external components while maintaining noise immunity and load drive margin.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN high-voltage power transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJD127G	Higher V_CEO (300 V), same TO-225 package, but lower h_FE min (10 vs. 25) and higher V_CE(sat) (1.5 V).	More suited to pure switching where gain stability is less critical; less ideal for linear audio stages requiring tight bias control.	Select MJD127G when higher voltage margin is prioritized over DC gain consistency and low saturation loss.
2N5551	Lower V_CEO (160 V), TO-92 package, higher f_T (100 MHz), but only 0.6 W P_D and no defined SOA curves.	Restricted to low-power signal amplification or logic-level switching; unsuitable for line-voltage or power-switching roles.	Choose 2N5551 only for sub-100 V, <100 mW small-signal applications-never as a functional replacement for 2N5655G in power roles.

Compared with MJD127G and 2N5551, the 2N5655G uniquely balances 250 V ruggedness, 20 W power capability, verified SOA for inductive loads, and sufficient h_FE for direct logic-level drive-making it irreplaceable in line-operated relay and audio output designs where all three attributes are simultaneously required.

Availability

2N5655G is available at Aetrix Electronics and suitable for audio output amplifiers, AC line relay drivers, and low-current high-voltage DC-DC converters requiring stable component supply and long-term industrial availability.

Supply support for 2N5655G 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 manufacturer specializing in energy-efficient power, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 2N5655G belongs to onsemi's legacy high-voltage bipolar power transistor family, engineered specifically for reliability in line-powered equipment including audio amplifiers, industrial controls, and AC-coupled switching interfaces.

FAQ

What is the maximum collector-emitter voltage rating for the 2N5655G?

The 2N5655G has a maximum collector-emitter voltage rating (V_CEO) of 250 Vdc, verified per JEDEC standards. This rating applies under DC and pulse conditions with I_B = 0. The sustaining voltage (V_CEO(sus)) is also 250 Vdc under inductive load testing (I_C = 100 mA, L = 50 mH). Exceeding this voltage risks avalanche breakdown or permanent device damage.

Does the 2N5655G have a documented safe operating area (SOA)?

Yes, the 2N5655G includes published SOA curves in its official datasheet (Figure 3), covering DC, pulsed, and inductive-load conditions up to 150°C junction temperature. These curves define simultaneous V_CE–I_C limits governed by thermal and second-breakdown boundaries-critical for designing reliable relay drivers and flyback converters using the 2N5655G.

What package type does the 2N5655G use, and how is the collector connected?

The 2N5655G uses the TO-225 package (Case 77-09, Style 1), a 4-pin plastic power transistor outline. Pins 2 and 4, along with the backside metal tab, are internally connected to the collector. This multi-terminal collector configuration improves current sharing and thermal conduction-key for stable operation of the 2N5655G in power applications.

Is the 2N5655G RoHS-compliant and lead-free?

Yes, the "G" suffix in 2N5655G explicitly denotes Pb-free construction and RoHS compliance per EU Directive 2011/65/EU. onsemi confirms this in the device marking diagram and thermal characteristics section of the datasheet. No lead-based solder or terminations are used in the 2N5655G manufacturing process.

What is the thermal resistance from junction to case for the 2N5655G?

The 2N5655G has a specified thermal resistance of R_JC = 6.25°C/W, measured from junction to case under standard mounting conditions. This value is essential for calculating heatsink requirements and verifying that junction temperature remains ≤150°C under worst-case power dissipation and ambient conditions for the 2N5655G.

2N5655G Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

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

Voltage - Collector Emitter Breakdown (Max):: 250 V

Vce Saturation (Max) @ Ib, Ic:: 10V @ 100mA, 500mA

Current - Collector Cutoff (Max):: 100µA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 30 @ 100mA, 10mV

Power - Max:: 20 W

Frequency - Transition:: 10MHz

Operating Temperature:: -65°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-126

2N5655G FAQ

1.How can I place an order for 2N5655G through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N5655G 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 2N5655G reliable?

The price and inventory of 2N5655G are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N5655G is usually 5 days.

3.What payment methods are accepted for 2N5655G?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N5655G transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N5655G?

2N5655G orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N5655G 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 2N5655G?

For technical support, including 2N5655G datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N5655G requirements.

6.How does Aetrix verify that 2N5655G is sourced from the original manufacturer or authorized distributors?

All 2N5655G 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 2N5655G meets industry standards.

7.What is the process for return or replacement of 2N5655G?

All 2N5655G units undergo pre-shipment inspection (PSI). If there is an issue with 2N5655G, 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 2N5655G part is unused and in its original packaging.

Return procedure for 2N5655G:

1.Submit a request within 90 days.

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

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