Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

onsemi MJE180STU

Name: MJE180STU
Brand: onsemi
SKU: MJE180STU
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: MJE180STU

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

Package:: TO-225AA, TO-126-3

Datasheet:: MJE180STU.pdf

Description:: TRANS NPN 40V 3A TO-126-3

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:229

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

MJE180STU from ON Semiconductor is an NPN epitaxial silicon transistor designed for low-power audio amplification and high-speed switching applications, with 40 V V_CEO, 60 V V_CBO, 3 A DC collector current, 12.5 W power dissipation at T_C = 25°C, and 50 MHz current gain bandwidth product.

For engineers reviewing the MJE180STU datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-126 package, V_CE(sat) of 0.3 V at I_C = 500 mA/I_B = 50 mA, h_FE range of 50–250, and suitability for linear amplifier stages and pulse-switching circuits requiring moderate voltage and current handling.

Technical Context

The MJE180STU operates as a general-purpose bipolar junction transistor with fixed-emitter configuration in TO-126 housing. Its design supports linear amplification (e.g., preamp stages) and saturated switching (e.g., relay drivers), enabled by V_BE(on) = 1.2 V at I_C = 500 mA and V_CE(sat) ≤ 1.7 V up to I_C = 3 A.

Thermal performance is defined by T_J = 150°C maximum junction temperature and power derating above T_C = 25°C, while safe operating area (SOA) curves confirm pulsed operation up to 100 µs at full voltage-current stress. Cob = 30 pF at V_CB = 10 V enables stable high-frequency response in audio and switching topologies.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum continuous collector-emitter voltage before breakdown; defines usable supply rail headroom in amplifier or switch designs.
I_C (DC)	3 A - Sustained collector current capability; supports medium-power output stages without forced cooling.
P_C (T_C=25°C)	12.5 W - Thermal power limit at case temperature 25°C; requires heatsinking for sustained operation near rating.
h_FE	50–250 - DC current gain range at V_CE = 1 V; enables predictable base drive sizing across production lots.
f_T	50 MHz - Current gain bandwidth product; ensures adequate small-signal gain up to mid-audio frequencies.
C_ob	30 pF - Output capacitance at V_CB = 10 V; limits high-frequency roll-off and affects switching speed in capacitive-load circuits.

Pinout & Package

Package: TO-126 - Three-lead plastic power package with integral heat slug; leads are emitter (pin 1), collector (pin 2), base (pin 3); mounting hole allows mechanical attachment to heatsink.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current exit path for majority carriers	Connected to ground or low-impedance return; determines common-emitter topology reference point.
2 (Collector)	Current entry path under forward bias	Connected to load or supply rail; carries full output current and dissipates most thermal energy.
3 (Base)	Control terminal for carrier injection	Receives current-limited drive signal; base resistance must be sized to achieve target I_B for saturation or linear operation.

Key Features

Feature	Design Value
Low V_CE(sat)	0.3 V at I_C = 500 mA/I_B = 50 mA - Minimizes conduction loss and self-heating in switching applications.
High f_T	50 MHz - Supports stable gain in audio preamplifier and broadband driver circuits up to ~10 MHz.
Wide h_FE range	50–250 - Enables robust bias network design across process variation without active compensation.
TO-126 thermal interface	Integral metal tab with mounting hole - Allows direct heatsink attachment for reliable 12.5 W dissipation at T_C = 25°C.

Applications

Audio Pre-Amplifier Stage	DC Motor Driver Switch
Use Scenario: Low-noise voltage amplification in battery-powered portable audio equipment with single-supply rails. IC Role / Device Role / Timing Role: NPN BJT configured in common-emitter topology to provide 20–30 dB voltage gain with minimal distortion. Use Value: V_BE(on) = 1.2 V and h_FE ≥ 50 ensure stable DC biasing and consistent small-signal gain across temperature.	Use Scenario: On/off control of 12 V brushed DC motors in industrial actuators with PWM input. IC Role / Device Role / Timing Role: Saturated switch driving motor coil through collector-emitter path; base driven by microcontroller GPIO. Use Value: V_CE(sat) ≤ 0.9 V at I_C = 1.5 A reduces resistive losses and improves efficiency over discrete MOSFET alternatives at <1 A.
Relay Coil Driver	Linear Power Supply Pass Transistor
Use Scenario: Driving 5–24 V electromagnetic relays in PLC I/O modules where galvanic isolation is required. IC Role / Device Role / Timing Role: High-current switch interfacing logic-level signals to inductive relay coils with flyback diode protection. Use Value: I_CP = 6 A pulse rating accommodates relay inrush current; Cob = 30 pF limits turn-off delay during fast deactivation.	Use Scenario: Series pass element in adjustable linear regulators delivering up to 2 A output current. IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output via base-emitter voltage feedback loop. Use Value: P_C = 12.5 W at T_C = 25°C supports 2 A × 5 V dropout = 10 W dissipation with margin for thermal transients.

Audio Pre-Amplifier Stage

DC Motor Driver Switch

Use Scenario: Low-noise voltage amplification in battery-powered portable audio equipment with single-supply rails.

IC Role / Device Role / Timing Role: NPN BJT configured in common-emitter topology to provide 20–30 dB voltage gain with minimal distortion.

Use Value: V_BE(on) = 1.2 V and h_FE ≥ 50 ensure stable DC biasing and consistent small-signal gain across temperature.

Use Scenario: On/off control of 12 V brushed DC motors in industrial actuators with PWM input.

IC Role / Device Role / Timing Role: Saturated switch driving motor coil through collector-emitter path; base driven by microcontroller GPIO.

Use Value: V_CE(sat) ≤ 0.9 V at I_C = 1.5 A reduces resistive losses and improves efficiency over discrete MOSFET alternatives at <1 A.

Relay Coil Driver

Linear Power Supply Pass Transistor

Use Scenario: Driving 5–24 V electromagnetic relays in PLC I/O modules where galvanic isolation is required.

IC Role / Device Role / Timing Role: High-current switch interfacing logic-level signals to inductive relay coils with flyback diode protection.

Use Value: I_CP = 6 A pulse rating accommodates relay inrush current; Cob = 30 pF limits turn-off delay during fast deactivation.

Use Scenario: Series pass element in adjustable linear regulators delivering up to 2 A output current.

IC Role / Device Role / Timing Role: Voltage-controlled current source regulating output via base-emitter voltage feedback loop.

Use Value: P_C = 12.5 W at T_C = 25°C supports 2 A × 5 V dropout = 10 W dissipation with margin for thermal transients.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MJE180	Same die, identical electrical specs; "STU" suffix denotes tape-and-reel packaging per ON Semi standard.	No functional difference; STU variant optimized for automated SMT placement vs. bulk MJE180.	Select MJE180STU for pick-and-place assembly; use MJE180 for manual prototyping or low-volume hand soldering.
2N3055	Higher V_CEO (60 V), higher I_C (15 A), but lower f_T (≤ 3 MHz) and larger TO-3 package.	Suitable for higher-power linear supplies or audio outputs, but not for compact PCB layouts or >1 MHz switching.	Choose 2N3055 only when >3 A DC current or >40 V V_CEO is required; MJE180STU offers better HF response and smaller footprint.

Compared with MJE180STU, the MJE180 offers identical performance in bulk form but lacks tape-and-reel logistics support, while the 2N3055 trades high-current capability for reduced frequency response and board space efficiency-making MJE180STU optimal for space-constrained, medium-power linear/switching roles.

Availability

MJE180STU is available at Aetrix Electronics and suitable for audio pre-amplifiers, relay drivers, DC motor controls, and linear regulator pass elements requiring stable component supply with consistent parametric performance across production lots.

Supply support for MJE180STU 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 power management, analog, sensor, and logic devices for automotive, industrial, and consumer applications.

The MJE180STU belongs to ON Semiconductor's legacy general-purpose bipolar transistor product line, originally developed by Fairchild and optimized for cost-sensitive, medium-power linear and switching functions in industrial control and audio systems.

FAQ

What is the maximum junction temperature rating for the MJE180STU?

The MJE180STU has a maximum junction temperature (T_J) of 150°C, as specified in its absolute maximum ratings table. This value defines the upper thermal limit for reliable operation; exceeding it risks permanent degradation of h_FE, increased leakage, or bond wire failure. Designers must ensure that actual T_J remains below 150°C under worst-case ambient and power dissipation conditions, using thermal resistance data and heatsink calculations. The MJE180STU datasheet provides derating curves to guide safe operation above T_C = 25°C.

Does the MJE180STU have a built-in base-emitter resistor?

No, the MJE180STU does not include any integrated base-emitter resistor. It is a standard three-terminal NPN bipolar junction transistor requiring external base drive circuitry-such as a current-limiting resistor or active current source-to establish proper bias conditions. This distinguishes it from digital transistors (e.g., MMBT2222A with R1/R2), which integrate on-chip resistors. The absence of internal resistors gives designers full flexibility in setting I_B for linear or saturated operation, but also places responsibility on the circuit designer to avoid overdriving the base.

Can the MJE180STU be used in Class AB audio amplifier output stages?

The MJE180STU is not recommended for Class AB push-pull output stages due to its 3 A DC collector current rating and 12.5 W power dissipation limit-insufficient for typical speaker-driving loads. However, it is well-suited for pre-amplifier or driver stages preceding output devices, where its 50 MHz f_T, low V_CE(sat), and h_FE stability support clean voltage gain and low-distortion signal conditioning. For final output, higher-rated devices like MJ15003 or TIP35C are more appropriate. Always verify SOA compliance under real-world load and thermal conditions when using MJE180STU in linear amplification.

What is the safe operating area (SOA) limitation for pulsed operation of the MJE180STU?

The MJE180STU SOA curve permits pulsed collector currents up to 10 A at V_CE = 10 V for durations ≤ 100 µs, decreasing to 3 A at V_CE = 40 V for the same pulse width. These limits are defined by second breakdown constraints and thermal inertia, not just average power. Pulse operation must respect both voltage and current boundaries simultaneously-exceeding either risks localized hot-spot formation and catastrophic failure. The SOA graph in the MJE180STU datasheet (Figure 5) must be consulted for exact pulse-width-dependent boundaries; transient thermal impedance data is not provided, so conservative derating is advised for repetitive pulses.

Is the MJE180STU RoHS compliant and halogen-free?

Yes, the MJE180STU is RoHS compliant and halogen-free, consistent with ON Semiconductor's corporate environmental policy and product marking standards. As a post-Fairchild-integration part, it meets JEDEC JS709B and IEC 61249-2-21 requirements for lead-free soldering compatibility and restricted substance content. The device carries the "Pb-Free" and "Halogen-Free" markings on its package and is listed in ON Semiconductor's official compliance database. No exemptions apply; full material declarations are available upon request through Aetrix Electronics' technical support team for MJE180STU.

MJE180STU Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

Package/Case:: TO-225AA, TO-126-3

Packaging:: Tube

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 3 A

Voltage - Collector Emitter Breakdown (Max):: 40 V

Vce Saturation (Max) @ Ib, Ic:: 1.7V @ 600mA, 3A

Current - Collector Cutoff (Max):: 100µA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 50 @ 100mA, 1V

Power - Max:: 1.5 W

Frequency - Transition:: 50MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-126-3

MJE180STU FAQ

1.How can I place an order for MJE180STU through Aetrix?

Please submit a Request for Quotation (RFQ) for MJE180STU 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 MJE180STU reliable?

The price and inventory of MJE180STU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MJE180STU is usually 5 days.

3.What payment methods are accepted for MJE180STU?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MJE180STU transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MJE180STU?

MJE180STU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MJE180STU 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 MJE180STU?

For technical support, including MJE180STU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MJE180STU requirements.

6.How does Aetrix verify that MJE180STU is sourced from the original manufacturer or authorized distributors?

All MJE180STU 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 MJE180STU meets industry standards.

7.What is the process for return or replacement of MJE180STU?

All MJE180STU units undergo pre-shipment inspection (PSI). If there is an issue with MJE180STU, 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 MJE180STU part is unused and in its original packaging.

Return procedure for MJE180STU:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…