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

onsemi MMBT3904_NL

Name: MMBT3904_NL
Brand: onsemi
SKU: MMBT3904_NL
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MMBT3904_NL

Manufacturer:: onsemi

Category:: Single Bipolar Transistors

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

Datasheet:: MMBT3904_NL.pdf

Description:: TRANS NPN 40V 0.2A SOT-23-3

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MMBT3904_NL from ON Semiconductor is an NPN general-purpose bipolar junction transistor used for amplification and switching in low-power analog and digital circuits. It delivers DC current gain (hFE) of 70–300 at IC = 1.0 mA, VCE = 1.0 V; collector-emitter saturation voltage of 0.2 V at IC = 10 mA/IB = 1.0 mA; and 300 MHz transition frequency (fT), suitable for signal conditioning in consumer audio and microcontroller I/O interface stages.

For engineers reviewing the MMBT3904_NL datasheet, pinout, applications, or equivalent options, key selection criteria include its SOT-23 package footprint, 200 mA continuous collector current rating, 40 V VCEO breakdown, thermal resistance of 357°C/W (RθJA), and verified performance across −55°C to +150°C operating temperature range.

Technical Context

The MMBT3904_NL operates as a discrete NPN BJT with fixed emitter-base and collector-base junction structures optimized for linear amplification and saturated switching. Its small-signal characteristics-300 MHz fT, 4.0 pF CobO, and 5.0 dB noise figure at 100 μA-support mid-band RF and audio preamplifier use cases where gain stability and low-noise operation are required.

Switching behavior is characterized by 35 ns delay time, 35 ns rise time, 200 ns storage time, and 50 ns fall time under standardized test conditions (VCC = 3.0 V, IC = 10 mA, IB1 = IB2 = 1.0 mA), enabling reliable digital logic level translation and pulse generation up to ~5 MHz.

Key Specifications

Parameter	Value and Actual Design Meaning
VCEO	40 V - Maximum safe collector-emitter voltage before breakdown; defines upper rail limit in switch or amplifier stage.
IC (continuous)	200 mA - Continuous collector current handling capacity; supports moderate-load switching (e.g., LED drivers, relay coils).
hFE	70–300 - DC current gain range at IC = 1.0 mA/VCE = 1.0 V; determines base drive requirements for saturation.
fT	300 MHz - Unity-gain bandwidth; enables stable amplification up to VHF band in tuned circuits.
RθJA	357°C/W - Junction-to-ambient thermal resistance in SOT-23 package on standard FR-4 PCB; informs derating above 25°C ambient.
P_D	350 mW - Maximum power dissipation at 25°C; requires thermal design consideration for >100 mA sustained operation.
VBE(sat)	0.65–0.85 V - Base-emitter saturation voltage at IC = 10 mA/IB = 1.0 mA; impacts minimum logic-high threshold compatibility.

Pinout & Package

MMBT3904_NL is housed in a JEDEC-standard SOT-23 (TO-236AB) surface-mount plastic package with 3 terminals and a 1.90 mm × 1.30 mm footprint. The device uses EBC pin configuration (Emitter–Base–Collector) when viewed from top with marking "1A" aligned left-to-right.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal	Reference node for bias network; connects to ground or low-side load return path.
2 (Base)	Control input	Accepts current-limited drive (e.g., MCU GPIO via series resistor); sets operating point.
3 (Collector)	Current source terminal	Connects to load and positive supply; carries amplified/saturated output current.

Key Features

Feature	Design Value
NPN bipolar construction	Enables conventional current flow from collector to emitter with base-controlled conduction-ideal for low-side switching and common-emitter amplifiers.
300 MHz fT	Supports wideband small-signal amplification without external compensation in audio and IF stages.
Low VCE(sat) = 0.2 V	Minimizes power loss and voltage drop in saturated switch mode, improving efficiency in battery-powered logic interfaces.
−55°C to +150°C operation	Validated for automotive under-hood, industrial control, and outdoor embedded applications without derating penalties below 125°C.
JEDEC SOT-23 footprint	Ensures compatibility with high-volume automated assembly and reflow profiles; matches industry-standard pick-and-place tooling.

Applications

Microcontroller I/O Interface	LED Driver Circuit
Use Scenario: Driving discrete LEDs from 3.3 V or 5 V microcontroller GPIO pins with current limiting. IC Role / Device Role / Timing Role: Low-side switch controlling LED anode-to-VCC path; operates in saturation region. Use Value: Delivers 20–100 mA LED current with <0.2 V dropout, preserving headroom and minimizing heat in compact PCB layouts.	Use Scenario: Switching indicator or status LEDs in industrial HMIs and sensor nodes. IC Role / Device Role / Timing Role: General-purpose NPN switch activated by digital control signals. Use Value: Enables fast turn-on/turn-off (<100 ns combined rise+fall) for PWM dimming at frequencies up to 5 MHz.
Audio Preamp Stage	Signal Level Translation
Use Scenario: Amplifying microphone or sensor outputs prior to ADC sampling in portable devices. IC Role / Device Role / Timing Role: Common-emitter small-signal amplifier with resistive bias network. Use Value: Provides 70–300 hFE gain and 5.0 dB noise figure at 100 μA, supporting SNR-critical front-end designs.	Use Scenario: Converting 1.8 V logic outputs to 5 V-compatible levels for legacy peripherals. IC Role / Device Role / Timing Role: Active pull-up switch translating low-voltage logic to higher rail. Use Value: Achieves clean edge transitions with 35 ns delay and 35 ns rise time, maintaining timing integrity in mixed-voltage systems.

Microcontroller I/O Interface

LED Driver Circuit

Use Scenario: Driving discrete LEDs from 3.3 V or 5 V microcontroller GPIO pins with current limiting.

IC Role / Device Role / Timing Role: Low-side switch controlling LED anode-to-VCC path; operates in saturation region.

Use Value: Delivers 20–100 mA LED current with <0.2 V dropout, preserving headroom and minimizing heat in compact PCB layouts.

Use Scenario: Switching indicator or status LEDs in industrial HMIs and sensor nodes.

IC Role / Device Role / Timing Role: General-purpose NPN switch activated by digital control signals.

Use Value: Enables fast turn-on/turn-off (<100 ns combined rise+fall) for PWM dimming at frequencies up to 5 MHz.

Audio Preamp Stage

Signal Level Translation

Use Scenario: Amplifying microphone or sensor outputs prior to ADC sampling in portable devices.

IC Role / Device Role / Timing Role: Common-emitter small-signal amplifier with resistive bias network.

Use Value: Provides 70–300 hFE gain and 5.0 dB noise figure at 100 μA, supporting SNR-critical front-end designs.

Use Scenario: Converting 1.8 V logic outputs to 5 V-compatible levels for legacy peripherals.

IC Role / Device Role / Timing Role: Active pull-up switch translating low-voltage logic to higher rail.

Use Value: Achieves clean edge transitions with 35 ns delay and 35 ns rise time, maintaining timing integrity in mixed-voltage systems.

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
PN2222A	TO-92 package; higher PD = 625 mW; RθJA = 200°C/W; VCEO = 40 V same; hFE min = 100 @ IC = 10 mA.	Through-hole mounting only; better thermal performance but larger board area; less suitable for space-constrained SMT designs.	Select PN2222A when through-hole prototyping or higher power dissipation (>350 mW) is needed; not drop-in for SOT-23 footprints.
BC847B	SOT-23 package; VCEO = 45 V; hFE = 200–450 @ IC = 2 mA; RθJA = 350°C/W; fT = 300 MHz; same pinout (EBC).	Higher hFE spread and slightly improved voltage margin; identical footprint and thermal profile; widely available in AEC-Q200 variants.	BC847B offers tighter hFE binning and automotive qualification options; direct SOT-23 replacement if higher gain consistency is required.

Compared with PN2222A and BC847B, the MMBT3904_NL provides balanced gain, speed, and thermal performance in the most widely adopted SOT-23 footprint-making it optimal for cost-sensitive, high-volume consumer and industrial control designs where proven reliability and second-source availability are critical.

Availability

MMBT3904_NL is available at Aetrix Electronics and suitable for microcontroller I/O interfacing, LED driver circuits, audio preamplifier stages, and signal level translation requiring stable component supply across production lifecycles.

Supply support for MMBT3904_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 is a global semiconductor supplier delivering energy-efficient, intelligent power and sensing solutions for automotive, industrial, cloud, medical, and IoT applications.

The MMBT3904_NL belongs to ON Semiconductor's general-purpose discrete transistor product line, engineered for broad compatibility in amplification and switching roles across consumer, computing, and industrial electronics.

FAQ

What is the maximum collector current rating for MMBT3904_NL?

The MMBT3904_NL has a continuous collector current rating of 200 mA at TA = 25°C. Derating is required above this temperature per its 2.8 mW/°C thermal coefficient. Pulse operation up to 100 mA is supported with appropriate duty cycle limits, as confirmed in the Fairchild/ON Semiconductor datasheet Rev. 1.1.0.

Does MMBT3904_NL have a documented pinout configuration?

Yes, MMBT3904_NL uses the standard SOT-23 EBC (Emitter–Base–Collector) pinout: Pin 1 = Emitter, Pin 2 = Base, Pin 3 = Collector, verified in the official ON Semiconductor datasheet and JEDEC TO-236AB specification. This matches industry-standard layout practices for NPN transistors in SOT-23 packages.

What is the typical transition frequency (fT) of MMBT3904_NL?

The MMBT3904_NL has a specified transition frequency (fT) of 300 MHz under test conditions of IC = 10 mA, VCE = 20 V, and f = 100 MHz. This value is measured and published in the official datasheet, confirming suitability for VHF-range small-signal amplification and high-speed switching.

Can MMBT3904_NL be used in automotive applications?

MMBT3904_NL is qualified for operation from −55°C to +150°C and meets JEDEC standards for reliability, but it is not AEC-Q200 qualified. For automotive applications requiring formal qualification, ON Semiconductor offers AEC-Q200 versions such as the NSS40301MR6T1G; MMBT3904_NL may be used in non-safety-critical auxiliary functions pending customer validation.

What is the thermal resistance (RθJA) of MMBT3904_NL in its SOT-23 package?

The MMBT3904_NL exhibits a junction-to-ambient thermal resistance (RθJA) of 357°C/W when mounted on a standard FR-4 PCB per the datasheet test condition (1.6″ × 1.6″ × 0.06″). This value directly informs thermal derating curves and maximum allowable power dissipation in real-world PCB layouts.

MMBT3904_NL Specifications

Product attributes: Attribute value

Manufacturer:: onsemi

Series:: -

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

Packaging:: -

Product Status:: Obsolete

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 200 mA

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

Vce Saturation (Max) @ Ib, Ic:: 300mV @ 5mA, 50mA

Current - Collector Cutoff (Max):: 50nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 100 @ 10mA, 1V

Power - Max:: 350 mW

Frequency - Transition:: 300MHz

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

MMBT3904_NL FAQ

1.How can I place an order for MMBT3904_NL through Aetrix?

Please submit a Request for Quotation (RFQ) for MMBT3904_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 MMBT3904_NL reliable?

The price and inventory of MMBT3904_NL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBT3904_NL is usually 5 days.

3.What payment methods are accepted for MMBT3904_NL?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBT3904_NL transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMBT3904_NL?

MMBT3904_NL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMBT3904_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 MMBT3904_NL?

For technical support, including MMBT3904_NL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBT3904_NL requirements.

6.How does Aetrix verify that MMBT3904_NL is sourced from the original manufacturer or authorized distributors?

All MMBT3904_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 MMBT3904_NL meets industry standards.

7.What is the process for return or replacement of MMBT3904_NL?

All MMBT3904_NL units undergo pre-shipment inspection (PSI). If there is an issue with MMBT3904_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 MMBT3904_NL part is unused and in its original packaging.

Return procedure for MMBT3904_NL:

1.Submit a request within 90 days.

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

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