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

onsemi 2N4401_J25Z

Name: 2N4401_J25Z
Brand: onsemi
SKU: 2N4401_J25Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 2N4401_J25Z

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: 2N4401_J25Z.pdf

Description:: TRANS NPN 40V 0.6A TO-92-3

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Product details

Overview

2N4401_J25Z from ON Semiconductor is an NPN general-purpose bipolar junction transistor (BJT) designed for medium-power amplification and switching applications with continuous collector current up to 600 mA, V_CEO = 40 V, and DC current gain (h_FE) ranging from 40 to 300 at I_C = 1.0–150 mA. It operates across –55°C to +150°C and is commonly used in low-voltage relay drivers, LED load switches, and signal amplification stages in industrial control modules.

For engineers reviewing the 2N4401_J25Z datasheet, pinout, applications, or equivalent options, key selection considerations include its TO-92 package thermal resistance (R_θJA = 200°C/W), saturation voltage (V_CE(sat) = 0.40 V @ I_C = 150 mA), f_T = 250 MHz bandwidth, and compatibility with through-hole prototyping and legacy PCB layouts.

Technical Context

The 2N4401_J25Z implements a silicon planar epitaxial NPN structure optimized for linear amplification and hard-switching operation. Its design supports stable h_FE over wide collector current ranges (0.1–500 mA) and features low base-emitter saturation voltage (0.75–1.20 V) and fast switching times (t_d = 15 ns, t_s = 225 ns) under defined bias conditions.

It is rated for V_CBO = 60 V and V_EBO = 6.0 V, enabling use in circuits with moderate voltage headroom and ESD-sensitive input stages. Thermal performance is specified for FR-4 PCB mounting (1.6" × 1.6"), with derating of 5.0 mW/°C above 25°C ambient.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum safe collector-emitter voltage before breakdown; defines upper rail limit in switch/amplifier designs.
I_C (continuous)	600 mA - Sustained collector current capability; supports driving relays, small solenoids, or logic-level fanout.
h_FE	40–300 - DC current gain range across 1.0–150 mA; enables predictable base drive sizing for saturation or active-mode biasing.
V_CE(sat)	0.40 V @ I_C=150 mA, I_B=15 mA - Low saturation voltage minimizes power loss and heating in switching applications.
f_T	250 MHz - Current gain-bandwidth product; supports audio-frequency amplification and fast digital switching up to ~20–30 MHz.
R_θJA	200 °C/W - Junction-to-ambient thermal resistance on standard FR-4; informs heatsinking requirements for >300 mA continuous operation.

Pinout & Package

2N4401_J25Z is supplied in the TO-92 3-lead through-hole plastic package (JEDEC TO-92 compliant), with leads arranged in straight-line configuration. Pin identification follows standard EBC (Emitter-Base-Collector) order when viewed with flat side facing outward and leads pointing downward.

Pin/Terminal	Circuit Role	Design Meaning
1 (Left)	Emitter (E)	Current sink node; connected to ground or low-side return path in common-emitter configurations.
2 (Center)	Base (B)	Control input; requires current-limited drive (e.g., via series resistor) to achieve target I_C and saturation.
3 (Right)	Collector (C)	Current source node; connects to load (e.g., relay coil, LED anode) and positive supply rail in low-side switch topology.

Key Features

Feature	Design Value
Medium-power switching capability	Supports 600 mA continuous collector current with <0.4 V saturation drop-reduces conduction loss in discrete load control.
Wide h_FE range across operating currents	h_FE = 40–300 at I_C = 1.0–150 mA-enables robust bias design without tight gain binning.
High f_T and fast switching	250 MHz f_T, t_s = 225 ns-suitable for pulse-width modulation (PWM) dimming and digital signal buffering up to 20 MHz.
Extended temperature operation	–55°C to +150°C junction range-validates use in automotive engine compartments and industrial motor control enclosures.

Applications

Relay Driver Circuit	LED Constant-Current Switch
Use Scenario: Driving 12 V, 100 mA electromagnetic relay coils in programmable logic controllers (PLCs). IC Role / Device Role / Timing Role: Low-side NPN switch controlling coil energization/de-energization with TTL-compatible base drive. Use Value: V_CE(sat) ≤ 0.40 V ensures <50 mW dissipation at full load, eliminating need for heatsink in compact DIN-rail modules.	Use Scenario: Switching high-brightness white LEDs (3.2 V, 350 mA) in industrial status indicators. IC Role / Device Role / Timing Role: Constant-current switch regulating LED current via emitter-resistor feedback and base bias. Use Value: h_FE ≥ 80 at I_C = 350 mA enables precise current setting with ±5% tolerance using standard 1% resistors.
Audio Pre-Amplifier Stage	Microcontroller GPIO Expander
Use Scenario: Single-transistor common-emitter amplifier boosting microphone signals (10–20 mV AC) to line level in sensor interface boards. IC Role / Device Role / Timing Role: Linear amplification stage with fixed bias network and emitter degeneration resistor. Use Value: f_T = 250 MHz and h_ie = 1.0–15.0 kΩ support flat 20 Hz–20 kHz response with minimal distortion at 1 V_PP output.	Use Scenario: Extending GPIO count of ARM Cortex-M0 microcontrollers to drive 5 V peripheral logic (e.g., 74HC-series ICs). IC Role / Device Role / Timing Role: Level-shifting buffer translating 3.3 V logic outputs to 5 V-compatible open-collector signals. Use Value: V_CEO = 40 V and I_C = 600 mA allow safe interfacing with mixed-voltage systems without external clamping diodes.

Relay Driver Circuit

LED Constant-Current Switch

Use Scenario: Driving 12 V, 100 mA electromagnetic relay coils in programmable logic controllers (PLCs).

IC Role / Device Role / Timing Role: Low-side NPN switch controlling coil energization/de-energization with TTL-compatible base drive.

Use Value: V_CE(sat) ≤ 0.40 V ensures <50 mW dissipation at full load, eliminating need for heatsink in compact DIN-rail modules.

Use Scenario: Switching high-brightness white LEDs (3.2 V, 350 mA) in industrial status indicators.

IC Role / Device Role / Timing Role: Constant-current switch regulating LED current via emitter-resistor feedback and base bias.

Use Value: h_FE ≥ 80 at I_C = 350 mA enables precise current setting with ±5% tolerance using standard 1% resistors.

Audio Pre-Amplifier Stage

Microcontroller GPIO Expander

Use Scenario: Single-transistor common-emitter amplifier boosting microphone signals (10–20 mV AC) to line level in sensor interface boards.

IC Role / Device Role / Timing Role: Linear amplification stage with fixed bias network and emitter degeneration resistor.

Use Value: f_T = 250 MHz and h_ie = 1.0–15.0 kΩ support flat 20 Hz–20 kHz response with minimal distortion at 1 V_PP output.

Use Scenario: Extending GPIO count of ARM Cortex-M0 microcontrollers to drive 5 V peripheral logic (e.g., 74HC-series ICs).

IC Role / Device Role / Timing Role: Level-shifting buffer translating 3.3 V logic outputs to 5 V-compatible open-collector signals.

Use Value: V_CEO = 40 V and I_C = 600 mA allow safe interfacing with mixed-voltage systems without external clamping diodes.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN switching and amplification applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT4401	SOT-23 surface-mount package; lower P_D = 350 mW; R_θJA = 357°C/W; same electrical specs except reduced thermal capability.	Used where board space is constrained and reflow assembly is required; unsuitable for >250 mA continuous loads without thermal relief.	Select MMBT4401 only when footprint miniaturization and automated assembly outweigh thermal derating needs.
2N2222A	Higher V_CEO = 40 V (same), but lower h_FE min = 35 at I_C = 10 mA; V_CE(sat) = 0.6 V @ I_C = 150 mA; slower f_T ≈ 250–300 MHz (less consistent).	Legacy replacement in older designs; less predictable gain stability at low currents; higher saturation loss in high-duty-cycle switching.	Choose 2N2222A only for backward compatibility; prefer 2N4401_J25Z for new designs requiring tighter h_FE control and lower V_CE(sat).

Compared with MMBT4401 and 2N2222A, the 2N4401_J25Z delivers superior thermal margin in TO-92 form factor, more consistent h_FE across operating points, and lower V_CE(sat)-making it optimal for cost-sensitive, through-hole, medium-current switching where reliability and ease of hand-soldering matter.

Availability

2N4401_J25Z is available at Aetrix Electronics and suitable for relay driver circuits, LED constant-current switches, audio pre-amplifier stages, and microcontroller GPIO expander interfaces requiring stable component supply and long-term obsolescence management.

Supply support for 2N4401_J25Z 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, sensing, and connectivity solutions for automotive, industrial, and cloud infrastructure markets.

The 2N4401_J25Z belongs to ON Semiconductor's legacy general-purpose BJT product line, engineered for robustness, manufacturability, and broad compatibility in discrete amplifier and switch applications across industrial control and consumer electronics.

FAQ

What is the maximum continuous collector current rating for the 2N4401_J25Z?

The 2N4401_J25Z is rated for a maximum continuous collector current (I_C) of 600 mA at T_A = 25°C. This rating assumes proper PCB thermal management per the datasheet's FR-4 layout guidelines. Derating is required above 25°C ambient-5.0 mW/°C-and actual usable current drops to ~300 mA at 85°C ambient due to thermal limits. The 2N4401_J25Z must not be operated beyond this limit without heatsinking or airflow.

Does the 2N4401_J25Z have a documented pinout configuration for TO-92 packaging?

Yes-the 2N4401_J25Z uses the standard TO-92 EBC (Emitter-Base-Collector) pinout: when viewing the flat side of the package with leads pointing downward, the leftmost pin is Emitter, center is Base, and rightmost is Collector. This matches JEDEC TO-92 specifications and is confirmed in ON Semiconductor's MMBT4401/D datasheet Figure 1 and physical dimension drawings.

What is the typical DC current gain (h_FE) of the 2N4401_J25Z at 10 mA collector current?

At I_C = 10 mA and V_CE = 1.0 V, the 2N4401_J25Z exhibits a typical h_FE of 100, with a guaranteed minimum of 80 per the datasheet's Electrical Characteristics table. This value is measured under standardized conditions and remains stable across production lots, supporting reliable base resistor calculations in amplifier and switch designs.

Can the 2N4401_J25Z be used in high-frequency switching applications above 10 MHz?

Yes-the 2N4401_J25Z has a current gain–bandwidth product (f_T) of 250 MHz and documented switching times (t_d = 15 ns, t_r = 20 ns, t_f = 30 ns), making it suitable for digital switching up to ~20–30 MHz with appropriate drive strength and layout. However, parasitic capacitances (C_cb = 6.5 pF, C_eb = 30 pF) require careful PCB routing to avoid unintended oscillation or ringing.

Is the 2N4401_J25Z RoHS-compliant and lead-free?

Yes-the 2N4401_J25Z is manufactured by ON Semiconductor in accordance with RoHS Directive 2011/65/EU and is lead-free. Its TO-92 package uses matte tin (Sn) lead finish, and compliance is verified per ON Semiconductor's material declarations and packaging documentation (e.g., PB-free marking on tape/reel labels and datasheet revision history).

2N4401_J25Z Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: Bulk

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 600 mA

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

Vce Saturation (Max) @ Ib, Ic:: 750mV @ 50mA, 500mA

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 150mA, 1V

Power - Max:: 625 mW

Frequency - Transition:: 250MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-92-3

2N4401_J25Z FAQ

1.How can I place an order for 2N4401_J25Z through Aetrix?

Please submit a Request for Quotation (RFQ) for 2N4401_J25Z 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 2N4401_J25Z reliable?

The price and inventory of 2N4401_J25Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 2N4401_J25Z is usually 5 days.

3.What payment methods are accepted for 2N4401_J25Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 2N4401_J25Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 2N4401_J25Z?

2N4401_J25Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 2N4401_J25Z 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 2N4401_J25Z?

For technical support, including 2N4401_J25Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 2N4401_J25Z requirements.

6.How does Aetrix verify that 2N4401_J25Z is sourced from the original manufacturer or authorized distributors?

All 2N4401_J25Z 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 2N4401_J25Z meets industry standards.

7.What is the process for return or replacement of 2N4401_J25Z?

All 2N4401_J25Z units undergo pre-shipment inspection (PSI). If there is an issue with 2N4401_J25Z, 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 2N4401_J25Z part is unused and in its original packaging.

Return procedure for 2N4401_J25Z:

1.Submit a request within 90 days.

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

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