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

onsemi 2N5551RLRPG

Name: 2N5551RLRPG
Brand: onsemi
SKU: 2N5551RLRPG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N5551RLRPG

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N5551RLRPG.pdf

Description:: TRANS NPN 160V 0.6A TO92

Quantity:: RFQ Add To RFQ list

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Product details

Overview

2N5551RLRPG from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for 160 V_CEO, 180 V_CBO, 600 mA continuous collector current, and 625 mW power dissipation at T_A = 25°C. It delivers h_FE ≥ 80 at I_C = 1.0 mA and supports high-frequency amplification up to 300 MHz f_T, commonly used in low-noise preamplifier stages and switching circuits.

For engineers reviewing the 2N5551RLRPG datasheet, pinout, applications, or equivalent options, key selection criteria include V_CEO/V_CBO ratings, h_FE consistency across I_C range, noise figure (8.0 dB), saturation voltage (V_CE(sat) ≤ 0.25 V at I_C/I_B = 10), and Pb-free TO-92 packaging compliance.

Technical Context

This discrete NPN bipolar junction transistor operates as a linear amplifier or saturated switch with verified DC current gain (h_FE) spanning 80–250 depending on collector current (1–50 mA) and V_CE = 5 V. Its 300 MHz transition frequency (f_T) and low output capacitance (C_obo ≤ 6.0 pF) support RF and wideband analog signal conditioning.

Thermal performance is defined by R_JA = 200°C/W and R_JC = 83.3°C/W, enabling reliable operation from −55°C to +150°C junction temperature. The device exhibits low noise (NF = 8.0 dB at I_C = 250 μA) and tight V_BE(sat) (≤ 1.2 V at I_C/I_B = 10), critical for precision biasing in multi-stage amplifiers.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	160 V - Maximum safe collector-emitter voltage before breakdown; enables use in 120 V rail switching and high-voltage amplifier stages.
I_C (continuous)	600 mA - Sustained collector current handling; supports medium-power driver and relay interface applications.
h_FE (min)	80 at I_C = 1.0 mA - Ensures stable small-signal gain in preamp and sensor interface circuits without external feedback compensation.
f_T	300 MHz - Enables amplification of VHF signals (e.g., FM receiver IF stages) and fast digital switching (t_r/t_f < 50 ns at V_CC = 30 V).
NF	8.0 dB at I_C = 250 μA - Low noise floor suitable for microphone preamps and low-level analog signal conditioning where SNR is critical.
V_CE(sat)	0.25 V max at I_C = 50 mA, I_B = 5 mA - Minimizes conduction loss in saturated-switch applications such as LED drivers and logic-level translators.
P_D @ T_A	625 mW - Power dissipation limit at ambient 25°C; requires heatsinking or derating above 25°C (5.0 mW/°C).

Pinout & Package

2N5551RLRPG uses the standard TO-92 (Case 29-11) plastic package with straight leads and Pb-free finish. Pin 1 is Emitter, Pin 2 is Base, Pin 3 is Collector - confirmed per onsemi marking diagram and package outline.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Reference node for bias network; connects to ground or emitter resistor in common-emitter configuration.
2 (Base)	Control input	Accepts current-limited drive (e.g., via 10 kΩ resistor); base-emitter junction must be forward-biased ≥ 0.7 V for turn-on.
3 (Collector)	Current source terminal	Connects to load and supply rail; handles full collector current and voltage swing up to 160 V_CEO.

Key Features

Feature	Design Value
Pb-free TO-92 package	Complies with RoHS Directive 2011/65/EU and JEDEC J-STD-020 reflow profile; compatible with automated tape-and-ammo assembly (2000 units/reel).
High V_CBO rating	180 V - Provides margin against transient overvoltage in inductive load switching (e.g., solenoid drivers) without snubber networks.
Low C_ibo	20 pF max - Reduces Miller effect and improves high-frequency stability in common-emitter amplifiers.
Guaranteed h_FE spread	Min 80 at I_C = 1.0 mA ensures predictable DC bias point in production designs without binning.
Wide T_J range	−55°C to +150°C - Supports deployment in automotive under-hood, industrial control, and outdoor telecom equipment.

Applications

Audio Preamplifier Stage	Switch-Mode Power Supply Driver
Use Scenario: Amplifying low-level microphone or piezoelectric sensor signals prior to ADC sampling in portable instrumentation. IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier operating in common-emitter configuration with emitter degeneration. Use Value: 8.0 dB noise figure and h_FE ≥ 80 at 1 mA ensure >60 dB SNR in 20 Hz–20 kHz band without active filtering.	Use Scenario: Driving gate of power MOSFET in flyback or forward converter auxiliary bias winding circuit. IC Role / Device Role / Timing Role: Saturated switch controlling current pulse to transformer primary during PWM off-time. Use Value: V_CE(sat) ≤ 0.25 V at 50 mA reduces conduction loss and thermal stress in compact enclosed power supplies.
RF Intermediate Frequency Amplifier	Industrial Relay Interface
Use Scenario: Boosting 10.7 MHz IF signal in FM radio receiver front-end before limiting and demodulation. IC Role / Device Role / Timing Role: Tuned common-emitter amplifier with parallel LC collector load and baseband coupling. Use Value: 300 MHz f_T and C_obo ≤ 6.0 pF maintain flat gain response and phase linearity across 88–108 MHz band.	Use Scenario: Isolating microcontroller GPIO from 24 VDC industrial relay coil with optocoupler-compatible drive capability. IC Role / Device Role / Timing Role: Digital switch translating 3.3 V/5 V logic to 24 V load control with current gain ≥ 80. Use Value: 160 V_CEO withstands relay coil flyback spikes up to 120 V, eliminating need for external clamp diode.

Audio Preamplifier Stage

Switch-Mode Power Supply Driver

Use Scenario: Amplifying low-level microphone or piezoelectric sensor signals prior to ADC sampling in portable instrumentation.

IC Role / Device Role / Timing Role: Discrete NPN transconductance amplifier operating in common-emitter configuration with emitter degeneration.

Use Value: 8.0 dB noise figure and h_FE ≥ 80 at 1 mA ensure >60 dB SNR in 20 Hz–20 kHz band without active filtering.

Use Scenario: Driving gate of power MOSFET in flyback or forward converter auxiliary bias winding circuit.

IC Role / Device Role / Timing Role: Saturated switch controlling current pulse to transformer primary during PWM off-time.

Use Value: V_CE(sat) ≤ 0.25 V at 50 mA reduces conduction loss and thermal stress in compact enclosed power supplies.

RF Intermediate Frequency Amplifier

Industrial Relay Interface

Use Scenario: Boosting 10.7 MHz IF signal in FM radio receiver front-end before limiting and demodulation.

IC Role / Device Role / Timing Role: Tuned common-emitter amplifier with parallel LC collector load and baseband coupling.

Use Value: 300 MHz f_T and C_obo ≤ 6.0 pF maintain flat gain response and phase linearity across 88–108 MHz band.

Use Scenario: Isolating microcontroller GPIO from 24 VDC industrial relay coil with optocoupler-compatible drive capability.

IC Role / Device Role / Timing Role: Digital switch translating 3.3 V/5 V logic to 24 V load control with current gain ≥ 80.

Use Value: 160 V_CEO withstands relay coil flyback spikes up to 120 V, eliminating need for external clamp diode.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
2N5551G	Bulk-packaged variant (5000 units) with identical electrical specs and TO-92 Pb-free construction.	No tape-and-reel or ammo-box packaging; suited for manual prototyping or low-volume hand-soldering.	Select 2N5551G when reel automation is unnecessary and cost-per-unit optimization favors bulk quantity.
MPSA42	Higher V_CEO (300 V) but lower h_FE (min 40) and higher V_CE(sat) (0.5 V); same TO-92 package.	Better for high-voltage AC line sensing; less suitable for low-noise audio due to higher NF (10 dB) and gain variation.	Choose MPSA42 only when >200 V blocking is mandatory and gain/noise requirements are relaxed.

Compared with 2N5551G and MPSA42, the 2N5551RLRPG offers optimal balance of high voltage rating, low noise, and tape-and-ammo packaging-making it preferred for automated production of mid-frequency amplifiers and industrial switching interfaces where reliability and assembly compatibility are critical.

Availability

2N5551RLRPG is available at Aetrix Electronics and suitable for audio preamplifier stages, RF intermediate frequency amplifiers, switch-mode power supply drivers, and industrial relay interfaces requiring stable component supply, Pb-free compliance, and TO-92 tape-and-ammo packaging.

Supply support for 2N5551RLRPG 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 delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The 2N5551RLRPG belongs to onsemi's legacy NPN amplifier transistor product line, engineered for general-purpose linear amplification and switching in cost-sensitive, high-reliability applications across consumer, industrial, and communications equipment.

FAQ

What is the maximum collector-emitter voltage rating for the 2N5551RLRPG?

The 2N5551RLRPG has a guaranteed minimum collector-emitter breakdown voltage (V_(BR)CEO) of 160 Vdc at I_C = 1.0 mA and I_B = 0. This rating is validated per onsemi's official datasheet and defines the absolute upper limit for safe DC operation in common-emitter configurations. Exceeding this voltage risks avalanche breakdown and permanent device failure.

Does the 2N5551RLRPG support high-frequency amplification, and what is its f_T?

Yes, the 2N5551RLRPG supports high-frequency amplification with a typical transition frequency (f_T) of 300 MHz measured at I_C = 10 mA, V_CE = 10 Vdc, and f = 100 MHz. This value is specified in the onsemi datasheet and confirms suitability for VHF applications including FM IF amplification and fast-switching digital interfaces.

What is the noise figure of the 2N5551RLRPG, and under what conditions is it measured?

The 2N5551RLRPG has a noise figure (NF) of 8.0 dB, measured at I_C = 250 μAdc, V_CE = 5.0 Vdc, R_S = 1.0 kΩ, and f = 1.0 kHz. This specification is explicitly listed in the onsemi datasheet's Electrical Characteristics table and reflects its low-noise capability in audio and sensor front-end applications.

Is the 2N5551RLRPG pin-compatible with the 2N5550 series?

Yes, the 2N5551RLRPG shares identical TO-92 pinout (Emitter-Base-Collector on Pins 1-2-3) and mechanical dimensions with the 2N5550 series, but differs electrically: it features higher V_CEO (160 V vs. 140 V), higher V_CBO (180 V vs. 160 V), and higher min h_FE (80 vs. 60). No PCB changes are required for drop-in replacement where voltage headroom is needed.

What packaging format does the 2N5551RLRPG use, and how many units are supplied per reel?

The 2N5551RLRPG is supplied in Pb-free TO-92 package using tape-and-ammo box packaging, with 2000 units per box. This format is confirmed in the onsemi ordering information table and supports automated pick-and-place assembly while maintaining RoHS compliance and moisture sensitivity level (MSL) Class 1 handling.

2N5551RLRPG Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-226-3, TO-92-3 Long Body, 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:: 300MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

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

2N5551RLRPG FAQ

1.How can I place an order for 2N5551RLRPG through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N5551RLRPG 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 2N5551RLRPG reliable?

The price and inventory of 2N5551RLRPG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N5551RLRPG is usually 5 days.

3.What payment methods are accepted for 2N5551RLRPG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N5551RLRPG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N5551RLRPG?

2N5551RLRPG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N5551RLRPG 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 2N5551RLRPG?

For technical support, including 2N5551RLRPG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N5551RLRPG requirements.

6.How does Aetrix verify that 2N5551RLRPG is sourced from the original manufacturer or authorized distributors?

All 2N5551RLRPG 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 2N5551RLRPG meets industry standards.

7.What is the process for return or replacement of 2N5551RLRPG?

All 2N5551RLRPG units undergo pre-shipment inspection (PSI). If there is an issue with 2N5551RLRPG, 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 2N5551RLRPG part is unused and in its original packaging.

Return procedure for 2N5551RLRPG:

1.Submit a request within 90 days.

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

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