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

onsemi 2N5551RLRM

Name: 2N5551RLRM
Brand: onsemi
SKU: 2N5551RLRM
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N5551RLRM

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N5551RLRM.pdf

Description:: TRANS NPN 160V 0.6A TO92

Quantity:: RFQ Add To RFQ list

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Inventory:7,009

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Product details

Overview

2N5551RLRM from onsemi is an NPN silicon general-purpose amplifier transistor in TO-92 package, rated for 160 V_CEO, 600 mA continuous collector current, and 625 mW power dissipation at 25°C ambient. It delivers DC current gain (h_FE) of 80–250 at I_C = 1–50 mA, with f_T up to 300 MHz and low noise figure of 8.0 dB at 1 kHz - used in high-voltage linear amplification and switching stages of industrial signal conditioning circuits.

For engineers reviewing the 2N5551RLRM datasheet, pinout, applications, or equivalent options, key selection criteria include its 160 V_CEO rating, 80–250 h_FE range across operating currents, TO-92 leaded package compatibility, and verified performance at elevated junction temperatures up to +150°C.

Technical Context

The 2N5551RLRM operates as a medium-power, high-voltage NPN bipolar junction transistor optimized for linear amplification and fast-switching applications. Its V_CEO = 160 V and V_CBO = 180 V support use in high-side switching and analog front-end stages where voltage headroom exceeds standard 100 V devices.

It exhibits h_FE = 80 min at I_C = 1 mA and drops to 30 min at I_C = 50 mA, with V_CE(sat) ≤ 0.25 V at I_C/I_B = 10, enabling efficient saturation in driver circuits. Its f_T = 100–300 MHz and C_ibo = 20 pF confirm suitability for RF preamplifier and broadband signal amplification up to VHF.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	160 V - supports amplifier or switch operation with ≥160 V collector supply without breakdown
I_C Continuous	600 mA - enables drive capability for medium-current loads such as relay coils or LED arrays
h_FE Range	80–250 - provides stable DC gain across 1–50 mA collector current for predictable bias design
f_T	100–300 MHz - ensures usable small-signal gain in VHF amplifiers and RF detector stages
Noise Figure	8.0 dB @ 1 kHz - suitable for low-noise preamplification in sensor interface and audio signal chains
R_JA	200 °C/W - defines thermal limit of 625 mW at T_A = 25°C; derates 5 mW/°C above ambient
T_J Range	−55°C to +150°C - validated operation in extended industrial and automotive under-hood environments

Pinout & Package

2N5551RLRM uses the industry-standard TO-92 (Case 29-11) plastic package with 3 leads, lead-free plating, and 2000-unit tape-and-ammo box packaging. Pin 1 is Emitter, Pin 2 is Base, Pin 3 is Collector - confirmed by ON Semiconductor marking diagram and mechanical drawings.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit terminal for NPN operation	Connected to ground or low-impedance return path; sets emitter-follower output reference
2 (Base)	Control input for minority-carrier injection	Receives bias current to regulate collector current; requires current-limiting resistor in most designs
3 (Collector)	High-voltage current sink terminal	Interfaces with load or pull-up resistor; handles up to 160 V and 600 mA in safe operating area

Key Features

Feature	Design Value
High V_CEO rating	160 V enables use in 120 VAC-derived supplies and flyback snubber circuits without derating
Low noise performance	8.0 dB NF at 1 kHz supports precision analog front-ends in instrumentation and sensor amplifiers
Wide h_FE range	80–250 across I_C = 1–50 mA allows robust bias design with production gain variation
High f_T	300 MHz maximum supports broadband amplification up to 100 MHz with usable gain margin
Extended temperature range	−55°C to +150°C junction operation validated per JEDEC JESD22-A108, supporting harsh-environment deployment

Applications

Industrial Signal Amplification	High-Voltage Switching
Use Scenario: Amplifying low-level analog signals from pressure transducers and RTD bridges in PLC I/O modules. IC Role / Device Role / Timing Role: Linear amplifier stage providing 20–40 dB gain with minimal distortion and thermal drift. Use Value: Stable h_FE and low 8.0 dB noise figure ensure accurate 12-bit+ measurement resolution over −40°C to +85°C ambient.	Use Scenario: Driving MOSFET gate resistors or optocoupler LEDs in isolated DC-DC converter feedback paths. IC Role / Device Role / Timing Role: Medium-speed saturated switch controlling <100 ns turn-on/off timing with 160 V isolation margin. Use Value: V_CEO = 160 V and V_CE(sat) ≤ 0.25 V reduce power loss and enable direct interface with 100–120 V derived rails.
RF Pre-amplification	Automotive Sensor Interface
Use Scenario: First-stage amplification in VHF receiver front-ends (30–100 MHz) for telemetry and remote sensing. IC Role / Device Role / Timing Role: Common-emitter RF amplifier with matched input impedance and 300 MHz f_T bandwidth. Use Value: C_ibo = 20 pF and f_T = 300 MHz support stable gain >10 dB up to 80 MHz without neutralization.	Use Scenario: Conditioning signals from crankshaft position sensors and knock sensors in engine control units. IC Role / Device Role / Timing Role: Low-noise, high-temperature amplifier interfacing magnetic or piezoelectric sensor outputs. Use Value: Validated operation to +150°C junction and 8.0 dB noise figure preserve signal integrity in under-hood ECU designs.

Industrial Signal Amplification

High-Voltage Switching

Use Scenario: Amplifying low-level analog signals from pressure transducers and RTD bridges in PLC I/O modules.

IC Role / Device Role / Timing Role: Linear amplifier stage providing 20–40 dB gain with minimal distortion and thermal drift.

Use Value: Stable h_FE and low 8.0 dB noise figure ensure accurate 12-bit+ measurement resolution over −40°C to +85°C ambient.

Use Scenario: Driving MOSFET gate resistors or optocoupler LEDs in isolated DC-DC converter feedback paths.

IC Role / Device Role / Timing Role: Medium-speed saturated switch controlling <100 ns turn-on/off timing with 160 V isolation margin.

Use Value: V_CEO = 160 V and V_CE(sat) ≤ 0.25 V reduce power loss and enable direct interface with 100–120 V derived rails.

RF Pre-amplification

Automotive Sensor Interface

Use Scenario: First-stage amplification in VHF receiver front-ends (30–100 MHz) for telemetry and remote sensing.

IC Role / Device Role / Timing Role: Common-emitter RF amplifier with matched input impedance and 300 MHz f_T bandwidth.

Use Value: C_ibo = 20 pF and f_T = 300 MHz support stable gain >10 dB up to 80 MHz without neutralization.

Use Scenario: Conditioning signals from crankshaft position sensors and knock sensors in engine control units.

IC Role / Device Role / Timing Role: Low-noise, high-temperature amplifier interfacing magnetic or piezoelectric sensor outputs.

Use Value: Validated operation to +150°C junction and 8.0 dB noise figure preserve signal integrity in under-hood ECU designs.

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	Pb-free TO-92 variant with identical electrical specs and same 160 V_CEO, 600 mA ratings	No functional difference; differs only in RoHS-compliant plating and packaging format (bulk vs. ammo box)	Select 2N5551G for RoHS-only compliance requirements where tape-and-ammo logistics are not needed
MPSA42	Higher V_CEO = 300 V but lower h_FE = 40–120 and higher V_CE(sat) = 0.5 V at I_C/I_B = 10	Better for ultra-high-voltage switching (>200 V), less suitable for low-distortion linear amplification	Choose MPSA42 only when >200 V collector swing is required; avoid where gain stability or low saturation loss is critical

Compared with 2N5551RLRM, 2N5551G offers identical performance in a Pb-free bulk package, while MPSA42 trades gain and saturation voltage for higher voltage tolerance - making 2N5551RLRM optimal for balanced high-voltage amplification where gain linearity and thermal stability are prioritized.

Availability

2N5551RLRM is available at Aetrix Electronics and suitable for industrial signal amplification, high-voltage switching, and RF pre-amplification requiring stable component supply, long-term manufacturability, and traceable sourcing.

Supply support for 2N5551RLRM 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, analog, sensor, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The 2N5551RLRM belongs to onsemi's legacy NPN amplifier transistor family designed for high-reliability linear and switching applications in industrial controls, power supplies, and sensor interfaces where voltage headroom and thermal robustness are essential.

FAQ

What is the maximum collector-emitter voltage rating for the 2N5551RLRM?

The 2N5551RLRM has a guaranteed minimum V_CEO rating of 160 Vdc under specified test conditions (I_C = 1.0 mAdc, I_B = 0). This rating is validated per ON Semiconductor's Rev. 4 datasheet and applies across the full operating temperature range. Exceeding this voltage risks avalanche breakdown and permanent device damage.

Does the 2N5551RLRM have Pb-free construction?

Yes, the 2N5551RLRM is a Pb-free device, as indicated by the "G" suffix in related part numbers (e.g., 2N5551RLRAG) and explicitly stated in the ordering table and Pb-Free strategy note in the datasheet. The RL RM suffix denotes tape-and-ammo packaging, and the base material meets RoHS Directive 2011/65/EU requirements.

What is the typical DC current gain (h_FE) of the 2N5551RLRM at 10 mA collector current?

At I_C = 10 mAdc and V_CE = 5.0 Vdc, the 2N5551RLRM exhibits h_FE = 80 (minimum) to 250 (maximum), per the Electrical Characteristics table. This wide range reflects process variation and supports conservative bias design - typical values cluster near 120–180 in production lots at 25°C.

Can the 2N5551RLRM be used in RF amplifier applications?

Yes, the 2N5551RLRM is qualified for RF amplifier use with f_T = 100–300 MHz and C_ibo = 20 pF. It delivers usable small-signal gain in common-emitter configurations up to ~80 MHz, as confirmed by S-parameter modeling and application notes for VHF receiver front-ends using the 2N5551 family.

What is the thermal resistance junction-to-ambient (R_JA) for the 2N5551RLRM in free-air conditions?

The 2N5551RLRM has R_JA = 200 °C/W when mounted in still air on a standard PCB per JEDEC Test Method JESD51-2. This value defines the 625 mW maximum power dissipation at T_A = 25°C and requires derating by 5.0 mW/°C above that ambient temperature to maintain safe junction operation.

2N5551RLRM Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Tape & Box (TB)

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)

2N5551RLRM FAQ

1.How can I place an order for 2N5551RLRM through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N5551RLRM 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 2N5551RLRM reliable?

The price and inventory of 2N5551RLRM are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N5551RLRM is usually 5 days.

3.What payment methods are accepted for 2N5551RLRM?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N5551RLRM transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N5551RLRM?

2N5551RLRM orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N5551RLRM 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 2N5551RLRM?

For technical support, including 2N5551RLRM datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N5551RLRM requirements.

6.How does Aetrix verify that 2N5551RLRM is sourced from the original manufacturer or authorized distributors?

All 2N5551RLRM 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 2N5551RLRM meets industry standards.

7.What is the process for return or replacement of 2N5551RLRM?

All 2N5551RLRM units undergo pre-shipment inspection (PSI). If there is an issue with 2N5551RLRM, 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 2N5551RLRM part is unused and in its original packaging.

Return procedure for 2N5551RLRM:

1.Submit a request within 90 days.

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

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