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

onsemi MMBT5551_NL

Name: MMBT5551_NL
Brand: onsemi
SKU: MMBT5551_NL
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMBT5551_NL

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: MMBT5551_NL.pdf

Description:: TRANS NPN 160V 0.6A SOT-23-3

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Product details

Overview

MMBT5551_NL from ON Semiconductor is an NPN general-purpose amplifier optimized for high-voltage linear 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 P_D = 350 mW in SOT-23 package.

For engineers reviewing the MMBT5551_NL datasheet, pinout, applications, or equivalent options, key selection criteria include high-voltage breakdown capability, DC current gain consistency across operating currents, thermal resistance (R_θJA = 357 °C/W), and compatibility with low-profile surface-mount layouts requiring minimal PCB real estate.

Technical Context

This device operates as a discrete NPN bipolar junction transistor with fixed emitter-base and collector-base junction structures, supporting linear amplification and switching modes. Its design emphasizes stable h_FE over I_C = 1–50 mA and low V_CE(sat) (0.15 V at I_C = 10 mA / I_B = 1 mA) for efficient active-region biasing.

Thermal performance is defined by R_θJA = 357 °C/W and maximum T_J = 150 °C, limiting continuous power dissipation to 350 mW at 25 °C ambient with linear derating of 2.8 mW/°C above that point. Small-signal behavior includes C_obo = 6.0 pF and C_ibo = 20 pF at specified reverse-bias conditions.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	160 V - Maximum collector-emitter voltage before breakdown; enables use in >100 V supply rails and HV display drivers.
I_C (max)	600 mA - Continuous collector current rating; supports medium-power amplification and switching loads.
h_FE	80–250 - DC current gain range at I_C = 10 mA, V_CE = 5 V; ensures predictable base drive requirements across production lots.
f_T	100 MHz - Current-gain bandwidth product at I_C = 10 mA, V_CE = 10 V; suitable for audio-frequency and low-MHz signal amplification.
P_D	350 mW - Total device power dissipation in SOT-23 package; requires thermal-aware PCB layout with adequate copper area.
R_θJA	357 °C/W - Junction-to-ambient thermal resistance; dictates temperature rise under load without heatsinking.
C_obo	6.0 pF - Output capacitance at V_CB = 10 V; impacts high-frequency gain roll-off and stability in amplifier stages.

Pinout & Package

SOT-23 (TO-236AB) 3-lead plastic surface-mount package with gull-wing leads; marking "3S" on top surface. Dimensions per JEDEC TO-236, variation AB, issue H.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Emission terminal for majority carriers	Reference node for bias network; connects to ground or low-impedance return path in common-emitter configurations.
2 (Base)	Control electrode for carrier injection	Receives current-limited drive signal; requires series resistor to limit I_B and prevent saturation-induced storage delay.
3 (Collector)	Current collection terminal	Connects to high-voltage supply rail or load; must withstand up to 160 V transient stress in display driver applications.

Key Features

Feature	Design Value
High V_CEO rating	160 V enables direct interface with neon/gas-discharge displays and legacy HV analog circuits without external level-shifting.
Wide h_FE range	80–250 at I_C = 10 mA allows consistent small-signal gain across process variations while maintaining predictable base drive.
Low V_CE(sat)	0.15 V at I_C = 10 mA / I_B = 1 mA reduces conduction loss in switching applications and improves efficiency in Class-A amplifiers.
100 MHz f_T	Supports stable amplification up to mid-audio frequencies with minimal phase shift, suitable for preamp and driver stages.
SOT-23 footprint	Standardized 3-pin surface-mount package enables automated assembly and space-constrained board designs without lead-forming.

Applications

Gas Discharge Display Driver	High-Voltage Linear Amplifier
Use Scenario: Driving segments of neon indicator tubes or Nixie displays requiring 90–150 V anode supplies. IC Role / Device Role / Timing Role: NPN switch controlling current through gas-discharge element via common-emitter configuration. Use Value: Withstands 160 V V_CEO and delivers 600 mA peak current, eliminating need for external HV transistors or charge pumps.	Use Scenario: Low-noise preamplifier stage in instrumentation amplifiers handling signals referenced to elevated supply rails. IC Role / Device Role / Timing Role: Linear-mode NPN amplifier biased in active region for signal gain with minimal distortion. Use Value: 100 MHz f_T and 8.0 dB noise figure support clean amplification of sub-MHz sensor outputs without added filtering.
Industrial Relay Driver	Legacy Interface Level Shifter
Use Scenario: Controlling 24–48 V DC coil relays in PLC I/O modules where microcontroller GPIOs lack sufficient drive strength. IC Role / Device Role / Timing Role: Switching transistor providing galvanic isolation between logic-level control and inductive load. Use Value: 600 mA I_C rating and 0.15 V V_CE(sat) minimize power loss and heat generation during sustained relay activation.	Use Scenario: Translating 3.3 V or 5 V logic signals to 12–24 V levels for compatibility with older industrial sensors and actuators. IC Role / Device Role / Timing Role: Emitter-follower or common-emitter level translator enabling bidirectional voltage domain bridging. Use Value: High h_FE and low V_BE(sat) (1.0 V) ensure reliable turn-on with minimal base current, reducing MCU port loading.

Gas Discharge Display Driver

High-Voltage Linear Amplifier

Use Scenario: Driving segments of neon indicator tubes or Nixie displays requiring 90–150 V anode supplies.

IC Role / Device Role / Timing Role: NPN switch controlling current through gas-discharge element via common-emitter configuration.

Use Value: Withstands 160 V V_CEO and delivers 600 mA peak current, eliminating need for external HV transistors or charge pumps.

Use Scenario: Low-noise preamplifier stage in instrumentation amplifiers handling signals referenced to elevated supply rails.

IC Role / Device Role / Timing Role: Linear-mode NPN amplifier biased in active region for signal gain with minimal distortion.

Use Value: 100 MHz f_T and 8.0 dB noise figure support clean amplification of sub-MHz sensor outputs without added filtering.

Industrial Relay Driver

Legacy Interface Level Shifter

Use Scenario: Controlling 24–48 V DC coil relays in PLC I/O modules where microcontroller GPIOs lack sufficient drive strength.

IC Role / Device Role / Timing Role: Switching transistor providing galvanic isolation between logic-level control and inductive load.

Use Value: 600 mA I_C rating and 0.15 V V_CE(sat) minimize power loss and heat generation during sustained relay activation.

Use Scenario: Translating 3.3 V or 5 V logic signals to 12–24 V levels for compatibility with older industrial sensors and actuators.

IC Role / Device Role / Timing Role: Emitter-follower or common-emitter level translator enabling bidirectional voltage domain bridging.

Use Value: High h_FE and low V_BE(sat) (1.0 V) ensure reliable turn-on with minimal base current, reducing MCU port loading.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose amplifier applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT5550_NL	V_CEO = 140 V (lower than MMBT5551_NL's 160 V); otherwise identical SOT-23 package, h_FE, and f_T.	Not suitable for >140 V display drivers or HV amplifier rails where MMBT5551_NL's 160 V margin is required.	Select MMBT5550_NL only when system voltage remains ≤140 V and cost optimization is prioritized.
PN2222A	Lower V_CEO = 40 V; higher R_θJA = 420 °C/W; TO-92 package (larger footprint, through-hole).	Limited to low-voltage logic interfacing and general-purpose switching; incompatible with HV display or industrial relay drivers.	Choose PN2222A only for prototyping or low-cost through-hole designs where voltage and thermal constraints are relaxed.

Compared with MMBT5551_NL, MMBT5550_NL offers cost savings but sacrifices 20 V of collector-emitter breakdown headroom, while PN2222A trades voltage capability, thermal performance, and package size for broader availability in legacy through-hole systems.

Availability

MMBT5551_NL is available at Aetrix Electronics and suitable for gas discharge display drivers, high-voltage linear amplifiers, and industrial relay interface circuits requiring stable component supply, long-term manufacturability, and RoHS-compliant SMT packaging.

Supply support for MMBT5551_NL 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 semiconductor manufacturer specializing in power management, analog, sensor, and discrete solutions for automotive, industrial, and consumer markets.

The MMBT5551_NL belongs to ON Semiconductor's general-purpose bipolar transistor product line, engineered for reliability in high-voltage amplification and switching applications where robustness, parameter consistency, and SMT scalability are critical.

FAQ

What is the maximum collector-emitter voltage rating for MMBT5551_NL?

The MMBT5551_NL has a guaranteed minimum V_CEO rating of 160 V at I_C = 1.0 mA and I_B = 0. This specification ensures safe operation in circuits with up to 160 V DC or peak AC across the collector-emitter terminals, such as gas discharge display drivers. Exceeding this voltage risks irreversible breakdown and device failure.

Does MMBT5551_NL support switching applications, and what is its typical V_CE(sat)?

Yes, MMBT5551_NL supports switching applications with V_CE(sat) = 0.15 V at I_C = 10 mA and I_B = 1.0 mA, and 0.20 V at I_C = 50 mA and I_B = 5.0 mA. These low saturation voltages reduce conduction losses in relay drivers and digital output stages, improving overall system efficiency and thermal performance.

What is the DC current gain (h_FE) range of MMBT5551_NL, and at what test conditions is it specified?

The MMBT5551_NL exhibits h_FE = 80–250 when tested at I_C = 10 mA and V_CE = 5.0 V. The gain varies with operating point: minimum 80 at I_C = 1.0 mA and 50 at I_C = 1.0 mA with V_CE = 10 V (small-signal condition). Designers must verify gain stability across their specific bias conditions using the published h_FE vs. I_C curves.

Is MMBT5551_NL compatible with standard SOT-23 pick-and-place equipment?

Yes, MMBT5551_NL uses the JEDEC-standard SOT-23 (TO-236AB) package with gull-wing leads and 0.95 mm lead pitch. It is fully compatible with industry-standard SMT assembly processes, including reflow soldering per J-STD-020, and supports tape-and-reel packaging for automated placement. The top marking "3S" aids optical recognition during placement verification.

How does the thermal performance of MMBT5551_NL compare to the through-hole 2N5551 variant?

MMBT5551_NL has R_θJA = 357 °C/W versus 200 °C/W for the TO-92-packaged 2N5551, reflecting its smaller SOT-23 footprint and reduced thermal mass. While MMBT5551_NL delivers the same electrical performance in a compact form factor, its lower power dissipation limit (350 mW vs. 625 mW) requires careful PCB thermal design-such as thermal vias and copper pours-to maintain junction temperature below 150 °C under continuous load.

MMBT5551_NL Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

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:: 350 mW

Frequency - Transition:: 100MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

MMBT5551_NL FAQ

1.How can I place an order for MMBT5551_NL through Aetrix?

Please submit a Request for Quotation (RFQ) for MMBT5551_NL 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 MMBT5551_NL reliable?

The price and inventory of MMBT5551_NL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBT5551_NL is usually 5 days.

3.What payment methods are accepted for MMBT5551_NL?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBT5551_NL transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMBT5551_NL?

MMBT5551_NL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMBT5551_NL 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 MMBT5551_NL?

For technical support, including MMBT5551_NL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBT5551_NL requirements.

6.How does Aetrix verify that MMBT5551_NL is sourced from the original manufacturer or authorized distributors?

All MMBT5551_NL 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 MMBT5551_NL meets industry standards.

7.What is the process for return or replacement of MMBT5551_NL?

All MMBT5551_NL units undergo pre-shipment inspection (PSI). If there is an issue with MMBT5551_NL, 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 MMBT5551_NL part is unused and in its original packaging.

Return procedure for MMBT5551_NL:

1.Submit a request within 90 days.

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

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