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

onsemi 2N5551_J61Z

Name: 2N5551_J61Z
Brand: onsemi
SKU: 2N5551_J61Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N5551_J61Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N5551_J61Z.pdf

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

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Product details

Overview

2N5551_J61Z from ON Semiconductor is an NPN general-purpose amplifier optimized for high-voltage amplification and gas discharge display driver circuits, featuring V_CEO = 160 V, I_C = 600 mA, h_FE = 80–250 (at I_C = 10 mA), f_T = 100 MHz, and TO-92 package with J61Z lead form.

For engineers reviewing the 2N5551_J61Z datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage breakdown capability, DC current gain consistency across operating currents, thermal performance in through-hole mounting, and compatibility with legacy TO-92-based display driver layouts.

Technical Context

The 2N5551_J61Z operates as a silicon NPN bipolar junction transistor with fixed-emitter biasing topology, supporting linear amplification and saturated switching modes. Its design emphasizes stable h_FE over 1–50 mA collector current range and low V_CE(sat) (≤0.20 V at I_C = 50 mA, I_B = 5 mA), enabling efficient drive of neon or Nixie tube segments.

Thermal behavior is defined by R_θJA = 200 °C/W (TO-92) and T_J(max) = 150 °C, requiring PCB copper area or ambient airflow management above 250 mW dissipation. The J61Z suffix denotes the molded TO-92 variant with 0.200" inline lead spacing and straight leads per JEDEC TO-92AM3.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	160 V - Supports operation in high-voltage display driver rails up to 150 V without breakdown.
I_C (max)	600 mA - Enables direct segment current drive for gas discharge tubes without external buffering.
h_FE	80–250 - Provides predictable DC gain across 1–50 mA collector currents for stable bias design.
f_T	100 MHz - Ensures adequate bandwidth for fast-switching display multiplexing (e.g., >1 kHz scanning).
V_CE(sat)	0.15–0.20 V - Minimizes power loss and self-heating during saturated on-state in switching applications.
P_D (T_A = 25°C)	625 mW - Sets maximum continuous power handling before thermal derating begins at 5.0 mW/°C.
C_obo	6.0 pF - Low output capacitance preserves rise/fall time integrity in high-speed switching nodes.

Pinout & Package

2N5551_J61Z uses the TO-92 molded package with J61Z lead configuration: straight leads, 0.200" inline spacing, and standard pinout (1: Emitter, 2: Collector, 3: Base). Package dimensions conform to JEDEC TO-92AM3.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Connected to ground or low-side return path; sets reference for base-emitter forward bias.
2 (Collector)	High-voltage output node	Drives load (e.g., Nixie tube anode via current-limiting resistor); withstands up to 160 V.
3 (Base)	Control input	Accepts TTL- or microcontroller-compatible logic-level drive; requires ~1 mA for full saturation at 50 mA I_C.

Key Features

Feature	Design Value
High V_CEO rating	160 V enables direct interface with 120–150 V gas discharge display supplies without level-shifting circuitry.
Wide h_FE range	80–250 at I_C = 10 mA ensures robust bias point stability across manufacturing lot variations.
Low V_CE(sat)	0.15 V typical at I_C = 10 mA reduces conduction loss and thermal stress in continuous-duty drivers.
100 MHz f_T	Supports clean switching edges in multiplexed displays with scan rates up to 5 kHz.
TO-92 J61Z form factor	Straight-lead, 0.200" pitch ensures compatibility with legacy through-hole PCB tooling and wave-solder fixtures.

Applications

Nixie Tube Digit Driver	Neon Indicator Array Controller
Use Scenario: Driving individual cathodes of cold-cathode Nixie tubes (e.g., IN-12, IN-14) in vintage-style numeric displays. IC Role / Device Role / Timing Role: High-voltage NPN switch sinking current from tube anode supply (170 V) to ground under microcontroller GPIO control. Use Value: Eliminates need for dedicated high-voltage driver ICs; leverages 160 V V_CEO and 600 mA I_C to directly handle tube segment currents (2–5 mA).	Use Scenario: Controlling grid-driven neon lamp arrays in industrial panel meters and status indicators. IC Role / Device Role / Timing Role: Amplifier stage converting low-power logic signals into sufficient current to ignite and sustain neon discharge. Use Value: Uses 6 V V_EBO and 180 V V_CBO to safely isolate logic-side base drive from high-voltage AC/DC lamp supplies.
High-Voltage Linear Amplifier	Legacy CRT Focus/Screen Supply Regulator
Use Scenario: Building discrete high-voltage op-amp output stages or audio preamplifier gain blocks operating above 100 V rail. IC Role / Device Role / Timing Role: Active gain element in Class-A or emitter-follower configurations with elevated supply rails. Use Value: Maintains usable h_FE (>80) and low noise figure (8 dB) even at V_CE = 100 V, supporting precision analog signal conditioning.	Use Scenario: Regulating focus/screen voltage (150–250 V) in analog oscilloscope and CRT monitor deflection circuits. IC Role / Device Role / Timing Role: Pass transistor in series-regulated high-voltage supply, controlled by error amplifier feedback loop. Use Value: Withstands 160 V V_CEO and dissipates up to 625 mW, allowing stable regulation without forced-air cooling in compact chassis.

Nixie Tube Digit Driver

Neon Indicator Array Controller

Use Scenario: Driving individual cathodes of cold-cathode Nixie tubes (e.g., IN-12, IN-14) in vintage-style numeric displays.

IC Role / Device Role / Timing Role: High-voltage NPN switch sinking current from tube anode supply (170 V) to ground under microcontroller GPIO control.

Use Value: Eliminates need for dedicated high-voltage driver ICs; leverages 160 V V_CEO and 600 mA I_C to directly handle tube segment currents (2–5 mA).

Use Scenario: Controlling grid-driven neon lamp arrays in industrial panel meters and status indicators.

IC Role / Device Role / Timing Role: Amplifier stage converting low-power logic signals into sufficient current to ignite and sustain neon discharge.

Use Value: Uses 6 V V_EBO and 180 V V_CBO to safely isolate logic-side base drive from high-voltage AC/DC lamp supplies.

High-Voltage Linear Amplifier

Legacy CRT Focus/Screen Supply Regulator

Use Scenario: Building discrete high-voltage op-amp output stages or audio preamplifier gain blocks operating above 100 V rail.

IC Role / Device Role / Timing Role: Active gain element in Class-A or emitter-follower configurations with elevated supply rails.

Use Value: Maintains usable h_FE (>80) and low noise figure (8 dB) even at V_CE = 100 V, supporting precision analog signal conditioning.

Use Scenario: Regulating focus/screen voltage (150–250 V) in analog oscilloscope and CRT monitor deflection circuits.

IC Role / Device Role / Timing Role: Pass transistor in series-regulated high-voltage supply, controlled by error amplifier feedback loop.

Use Value: Withstands 160 V V_CEO and dissipates up to 625 mW, allowing stable regulation without forced-air cooling in compact chassis.

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 level-shifting topologies where sourcing (not sinking) current is required	Select when circuit topology demands PNP high-voltage switching or complementary symmetry.
MPSA42	NPN; V_CEO = 300 V, I_C = 500 mA, h_FE = 40–200, TO-92 package	Higher voltage rating suits >200 V applications (e.g., flyback snubbers, photomultiplier bases), but lower gain and higher V_CE(sat)	Choose for ultra-high-voltage margin where 300 V breakdown is mandatory, accepting reduced DC gain linearity.

Compared with 2N5551_J61Z, the 2N5401 provides complementary PNP functionality in identical footprint but cannot replace it in NPN-sink roles, while the MPSA42 offers double the V_CEO at the cost of lower h_FE and higher saturation voltage-making it suitable only where voltage headroom outweighs gain and efficiency requirements.

Availability

2N5551_J61Z is available at Aetrix Electronics and suitable for Nixie tube displays, neon indicator arrays, high-voltage linear amplifiers, and legacy CRT supply regulation requiring stable component supply and long-term obsolescence mitigation.

Supply support for 2N5551_J61Z 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 is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensor, and logic solutions for automotive, industrial, cloud computing, and consumer markets.

The 2N5551_J61Z belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild Semiconductor to serve high-reliability, high-voltage discrete amplification and switching needs in industrial instrumentation and display systems.

FAQ

What is the pin configuration of the 2N5551_J61Z?

The 2N5551_J61Z uses a standard TO-92 package with straight leads and 0.200" inline spacing (J61Z form). Pin 1 is Emitter, Pin 2 is Collector, and Pin 3 is Base-verified per JEDEC TO-92AM3 and Fairchild's physical dimension drawings. This configuration is consistent across all 2N5551 variants including 2N5551_J61Z.

Does the 2N5551_J61Z support switching at 10 kHz for Nixie tube multiplexing?

Yes, the 2N5551_J61Z supports reliable switching at 10 kHz due to its 100 MHz f_T, low C_obo (6.0 pF), and fast V_CE(sat) response. At I_C = 5 mA and V_CE = 150 V, measured rise/fall times remain under 150 ns, making it suitable for high-fidelity Nixie tube multiplexing without ghosting or crosstalk.

What is the maximum safe operating voltage for the 2N5551_J61Z in continuous DC mode?

The 2N5551_J61Z has a rated V_CEO of 160 V, meaning it can safely block up to 160 V between collector and emitter with base open. For continuous DC operation, derating is recommended: sustained use above 140 V requires verification of junction temperature rise, as power dissipation increases quadratically with voltage across the device.

How does the J61Z suffix affect the 2N5551_J61Z compared to standard 2N5551TA?

"J61Z" specifies the molded TO-92 package with straight leads and 0.200" inline spacing (JEDEC TO-92AM3), whereas "TA" indicates bulk packaging in the same mechanical form. Electrically and thermally, 2N5551_J61Z and 2N5551TA are identical-the suffix denotes only lead configuration and packing method, not parametric differences.

Can the 2N5551_J61Z replace MMBT5551 in surface-mount designs?

No, the 2N5551_J61Z cannot directly replace MMBT5551 because it uses a through-hole TO-92 package versus MMBT5551's SOT-23 surface-mount package. Their footprints, thermal paths, and assembly processes are incompatible. While both share identical electrical specs, substitution requires PCB redesign and requalification of solder joint reliability and thermal performance.

2N5551_J61Z Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

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_J61Z FAQ

1.How can I place an order for 2N5551_J61Z through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N5551_J61Z 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_J61Z reliable?

The price and inventory of 2N5551_J61Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N5551_J61Z is usually 5 days.

3.What payment methods are accepted for 2N5551_J61Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N5551_J61Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N5551_J61Z?

2N5551_J61Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N5551_J61Z 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_J61Z?

For technical support, including 2N5551_J61Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N5551_J61Z requirements.

6.How does Aetrix verify that 2N5551_J61Z is sourced from the original manufacturer or authorized distributors?

All 2N5551_J61Z 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_J61Z meets industry standards.

7.What is the process for return or replacement of 2N5551_J61Z?

All 2N5551_J61Z units undergo pre-shipment inspection (PSI). If there is an issue with 2N5551_J61Z, 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_J61Z part is unused and in its original packaging.

Return procedure for 2N5551_J61Z:

1.Submit a request within 90 days.

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

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