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

onsemi 2N5551_J05Z

Name: 2N5551_J05Z
Brand: onsemi
SKU: 2N5551_J05Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N5551_J05Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-226-3, TO-92-3 (TO-226AA)

Datasheet:: 2N5551_J05Z.pdf

Description:: TRANS NPN 160V 0.6A TO-92-3

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Product details

Overview

2N5551_J05Z from ON Semiconductor (formerly Fairchild) is an NPN general-purpose amplifier optimized for high-voltage linear amplification and gas discharge display driver circuits. It delivers V_CEO = 160 V, I_C = 600 mA continuous, h_FE = 80–250 (at I_C = 10 mA), f_T = 100 MHz, and operates across –55°C to +150°C junction temperature.

For engineers reviewing the 2N5551_J05Z datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage breakdown margin, DC gain stability at 10–50 mA collector current, low V_CE(sat) under forced-beta drive, thermal resistance in TO-92 packaging, and suitability for discrete amplifier stages in industrial power supplies and legacy display systems.

Technical Context

This device implements a planar epitaxial NPN transistor structure with optimized base doping and geometry to sustain 160 V collector-emitter breakdown while maintaining usable current gain up to 50 mA. Its 100 MHz f_T supports medium-frequency small-signal amplification, and its 6.0 pF C_obo enables stable operation in high-impedance collector loads.

The 2N5551_J05Z is characterized for DC and pulsed operation with validated thermal derating (5.0 mW/°C above 25°C) and specified cutoff currents (I_CBO ≤ 50 nA at 120 V, 25°C), confirming suitability for high-impedance bias networks and precision analog front-ends where leakage must be minimized.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	160 V - Supports operation in 120 V AC line-referenced circuits with safety margin.
I_C (continuous)	600 mA - Enables use as a medium-current switch or driver stage without external heat sinking.
h_FE range	80–250 at I_C = 10 mA - Provides predictable DC biasing for Class-A amplifiers and active loads.
f_T	100 MHz - Sufficient for RF predriver, oscillator, and broadband audio amplifier applications.
V_CE(sat)	0.15 V at I_C = 10 mA / I_B = 1 mA - Minimizes conduction loss in saturated-switch configurations.
R_θJA	200 °C/W - Requires PCB copper area or airflow for sustained >300 mW dissipation at ambient >50°C.
C_obo	6.0 pF at V_CB = 10 V - Limits Miller effect in common-emitter gain stages up to ~50 MHz.

Pinout & Package

2N5551_J05Z is supplied in the TO-92 3-lead through-hole package (JEDEC TO-92 compliant), with lead configuration: Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base. The package provides mechanical robustness and solderability for manual and wave-solder assembly.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Connected to ground or low-impedance return path; defines reference for V_BE and I_E.
2 (Collector)	High-voltage output terminal	Drives load toward positive supply; withstands 160 V with controlled leakage below 50 nA.
3 (Base)	Control input terminal	Accepts current-limited drive (e.g., via 10 kΩ resistor); requires ≥0.7 V to forward-bias junction.

Key Features

Feature	Design Value
High V_CEO rating	160 V enables direct interface with 100–120 V AC rectified rails in offline power supplies and lamp drivers.
Low noise figure	8.0 dB (10 Hz–15.7 kHz) supports use in low-level signal amplification without added audible noise.
Stable h_FE over I_C	h_FE ≥ 80 at I_C = 50 mA ensures reliable gain in medium-current switching and amplification stages.
Low C_ibo	20 pF at V_BE = 0.5 V minimizes input loading in high-Z base-drive networks and feedback paths.
Wide T_J range	–55°C to +150°C operation allows deployment in automotive under-hood, industrial motor control, and outdoor lighting environments.

Applications

Gas Discharge Display Driver	High-Voltage Linear Amplifier
Use Scenario: Driving neon or Nixie tube segments from microcontroller GPIO via current-limiting resistors. IC Role / Device Role / Timing Role: High-voltage NPN switch that sinks segment current while withstanding 120–150 V anode voltage. Use Value: Eliminates need for dedicated HV driver ICs; leverages 160 V V_CEO and 600 mA I_C to directly control legacy displays.	Use Scenario: Building discrete Class-A audio or instrumentation amplifier stages requiring >100 V supply headroom. IC Role / Device Role / Timing Role: Active gain element in common-emitter topology with emitter degeneration for linearity. Use Value: Delivers 100 MHz f_T and stable h_FE across 1–50 mA, enabling wideband amplification without gain collapse.
AC Line-Sensing Circuit	Industrial Relay Driver
Use Scenario: Detecting presence of 100–240 V AC mains using resistive divider and transistor-based zero-crossing detection. IC Role / Device Role / Timing Role: High-impedance input switch activated by scaled-down AC waveform. Use Value: I_CBO ≤ 50 nA at 120 V ensures minimal false triggering; V_BRCBO = 180 V guarantees reliability under surge conditions.	Use Scenario: Driving 12–48 V DC coils of industrial control relays from logic-level outputs. IC Role / Device Role / Timing Role: Saturated switch providing low-loss coil energization with fast turn-off via base discharge. Use Value: V_CE(sat) = 0.15 V at 10 mA reduces power loss; 600 mA I_C accommodates relay inrush currents up to 500 mA.

Gas Discharge Display Driver

High-Voltage Linear Amplifier

Use Scenario: Driving neon or Nixie tube segments from microcontroller GPIO via current-limiting resistors.

IC Role / Device Role / Timing Role: High-voltage NPN switch that sinks segment current while withstanding 120–150 V anode voltage.

Use Value: Eliminates need for dedicated HV driver ICs; leverages 160 V V_CEO and 600 mA I_C to directly control legacy displays.

Use Scenario: Building discrete Class-A audio or instrumentation amplifier stages requiring >100 V supply headroom.

IC Role / Device Role / Timing Role: Active gain element in common-emitter topology with emitter degeneration for linearity.

Use Value: Delivers 100 MHz f_T and stable h_FE across 1–50 mA, enabling wideband amplification without gain collapse.

AC Line-Sensing Circuit

Industrial Relay Driver

Use Scenario: Detecting presence of 100–240 V AC mains using resistive divider and transistor-based zero-crossing detection.

IC Role / Device Role / Timing Role: High-impedance input switch activated by scaled-down AC waveform.

Use Value: I_CBO ≤ 50 nA at 120 V ensures minimal false triggering; V_BRCBO = 180 V guarantees reliability under surge conditions.

Use Scenario: Driving 12–48 V DC coils of industrial control relays from logic-level outputs.

IC Role / Device Role / Timing Role: Saturated switch providing low-loss coil energization with fast turn-off via base discharge.

Use Value: V_CE(sat) = 0.15 V at 10 mA reduces power loss; 600 mA I_C accommodates relay inrush currents up to 500 mA.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2N5401	PNP complement; V_CEO = 150 V, h_FE = 60–240, same TO-92 package	Used in complementary push-pull or differential pair configurations, not direct replacement	Select when building matched NPN/PNP pairs or needing PNP polarity in high-voltage analog circuits.
MPSA42	V_CEO = 300 V, I_C = 500 mA, h_FE = 40–200, TO-92 package	Higher breakdown but lower gain and higher V_CE(sat); suited for ultra-high-voltage flyback snubbers	Choose for >200 V applications where 2N5551_J05Z's 160 V margin is insufficient, accepting reduced DC gain.

Compared with 2N5551_J05Z, the 2N5401 offers complementary PNP functionality rather than drop-in substitution, while the MPSA42 trades gain and saturation voltage for extended 300 V breakdown-making it suitable only where voltage stress exceeds 160 V, not for general-purpose amplification.

Availability

2N5551_J05Z is available at Aetrix Electronics and suitable for industrial relay drivers, gas discharge display systems, AC line sensing circuits, and high-voltage linear amplifier stages requiring stable component supply and long-term obsolescence management.

Supply support for 2N5551_J05Z 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

ON Semiconductor (formerly Fairchild Semiconductor) is a global leader in intelligent power and sensing solutions, serving automotive, industrial, cloud computing, and consumer markets with energy-efficient semiconductor technologies.

The 2N5551_J05Z belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, designed specifically for cost-sensitive, high-reliability discrete amplifier and switching applications in industrial controls and legacy display systems.

FAQ

What is the pin configuration of the 2N5551_J05Z?

The 2N5551_J05Z uses the standard TO-92 package with pinout: Pin 1 = Emitter, Pin 2 = Collector, Pin 3 = Base. This configuration is confirmed in Fairchild's original datasheet Rev. 1.1.0 and maintained in ON Semiconductor's cross-reference documentation. The device does not support alternate pinouts such as center-collector variants unless explicitly suffixed (e.g., "-C"), which 2N5551_J05Z does not carry.

Does the 2N5551_J05Z support operation at elevated temperatures?

Yes, the 2N5551_J05Z is rated for junction temperatures from –55°C to +150°C and features thermal resistance R_θJA = 200 °C/W. At ambient temperatures above 50°C, derating is required: power dissipation must decrease by 5.0 mW per °C above 25°C. This makes the 2N5551_J05Z suitable for under-hood automotive modules and enclosed industrial controllers when mounted on adequate copper area.

What is the typical DC current gain (h_FE) of the 2N5551_J05Z at 50 mA collector current?

The 2N5551_J05Z has a minimum h_FE of 30 at I_C = 50 mA, V_CE = 5.0 V, per the official Electrical Characteristics table. While h_FE reaches 80–250 at lower currents (1–10 mA), gain rolls off predictably at higher currents-enabling stable bias design for medium-power switching and amplification without thermal runaway.

Can the 2N5551_J05Z replace the MMBT5551 in surface-mount designs?

No-the 2N5551_J05Z is a TO-92 through-hole device and is not a drop-in replacement for the SOT-23 packaged MMBT5551. They share identical electrical specifications but differ in package, thermal performance (R_θJA = 200 vs. 357 °C/W), and mounting method. Substitution requires PCB redesign; the 2N5551_J05Z is intended for through-hole applications where mechanical robustness and hand-soldering compatibility are prioritized.

Is the 2N5551_J05Z suitable for use in life support or medical devices?

No. Per ON Semiconductor's official policy, the 2N5551_J05Z is not designed, intended, or authorized for use as a critical component in life support systems or FDA Class 3 medical devices. Its qualification excludes implantable or safety-critical applications. Engineers must select components explicitly certified for such use cases and perform full system-level validation independent of the 2N5551_J05Z datasheet parameters.

2N5551_J05Z Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 (TO-226AA)

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 600 mA

Voltage - Collector Emitter Breakdown (Max):: 160 V

Vce Saturation (Max) @ Ib, Ic:: 200mV @ 5mA, 50mA

Current - Collector Cutoff (Max):: 50nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 80 @ 10mA, 5V

Power - Max:: 625 mW

Frequency - Transition:: 100MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

2N5551_J05Z FAQ

1.How can I place an order for 2N5551_J05Z through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N5551_J05Z 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 2N5551_J05Z reliable?

The price and inventory of 2N5551_J05Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N5551_J05Z is usually 5 days.

3.What payment methods are accepted for 2N5551_J05Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N5551_J05Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N5551_J05Z?

2N5551_J05Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N5551_J05Z 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 2N5551_J05Z?

For technical support, including 2N5551_J05Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N5551_J05Z requirements.

6.How does Aetrix verify that 2N5551_J05Z is sourced from the original manufacturer or authorized distributors?

All 2N5551_J05Z 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 2N5551_J05Z meets industry standards.

7.What is the process for return or replacement of 2N5551_J05Z?

All 2N5551_J05Z units undergo pre-shipment inspection (PSI). If there is an issue with 2N5551_J05Z, 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 2N5551_J05Z part is unused and in its original packaging.

Return procedure for 2N5551_J05Z:

1.Submit a request within 90 days.

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

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