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

Diodes Incorporated MMBT3904-13

Name: MMBT3904-13
Brand: Diodes Incorporated
SKU: MMBT3904-13
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: MMBT3904-13

Manufacturer:: Diodes Incorporated

Category:: Single Bipolar Transistors

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

Datasheet:: MMBT3904-13.pdf

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

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:7,169

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

Product details

Overview

MMBT3904-13 from Diodes Incorporated is an NPN small-signal surface-mount transistor in SOT-23 package, rated for 40 V V_CEO, 200 mA I_C, and 350 mW P_D. It delivers h_FE = 100–300 at I_C = 10–100 mA and f_T = 300 MHz, serving as a general-purpose amplifier and switch in low-voltage logic interfaces and sensor signal conditioning circuits.

For engineers reviewing the MMBT3904-13 datasheet, MMBT3904-13 pinout, MMBT3904-13 application, or MMBT3904-13 equivalent, key selection criteria include verified V_CEO/I_C derating at +125°C, h_FE consistency across I_C = 1–50 mA, switching timing (t_r/t_f ≤ 35/50 ns), and SOT-23 thermal resistance (R_JA = 357 K/W) under PCB-defined copper area conditions.

Technical Context

This epitaxial planar NPN transistor operates in active, saturation, and cutoff regions with defined DC gain curves (h_FE = 40–300 across I_C = 0.1–100 mA at V_CE = 1 V) and small-signal parameters including h_fe = 100–400 and f_T = 300 MHz at V_CE = 20 V, I_C = 10 mA. Its breakdown ratings-V_(BR)CEO = 40 V, V_(BR)CBO = 60 V, V_(BR)EBO = 5.0 V-are validated per pulse test (300 µs, 2% duty).

Switching behavior is characterized by t_d = 35 ns, t_r = 35 ns, t_s = 200 ns, and t_f = 50 ns under V_CC = 3.0 V, I_C = 10 mA, and matched base drive (I_B1 = I_B2 = 1.0 mA), supporting medium-speed digital logic interfacing and PWM-driven LED bias control.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum collector-emitter voltage before avalanche in common-emitter configuration; defines safe operating range in 3.3 V/5 V logic-level switching.
I_C (cont.)	200 mA - Continuous collector current limit at T_A = 25°C; derates to ~120 mA at T_A = 85°C per R_JA = 357 K/W.
h_FE	100–300 - DC current gain at I_C = 10–100 mA, V_CE = 1 V; enables predictable base drive sizing for saturation in switching designs.
f_T	300 MHz - Transition frequency at V_CE = 20 V, I_C = 10 mA; supports amplification up to ~100 MHz with usable gain margin.
t_r/t_f	35/50 ns - Rise/fall times under specified 3 V switching conditions; suitable for ≤3 MHz square-wave applications with minimal overshoot.
R_JA	357 K/W - Junction-to-ambient thermal resistance on standard FR-4 with minimal copper; requires thermal relief design for >100 mA continuous operation.

Pinout & Package

Package: SOT-23 - Surface-mount plastic case with gull-wing leads, 0.008 g mass, compliant with MIL-STD-202 solderability requirements. Marking codes include K1N, R1A, or 1AM.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	Current sink terminal in common-emitter configuration	Connected to ground or low-impedance return path; sets reference for V_BE bias and emitter degeneration stability.
2 (Base)	Control input for minority-carrier injection	Receives current-limited drive (e.g., via 10 kΩ resistor); V_BE(SAT) = 0.65–0.95 V defines required forward bias headroom.
3 (Collector)	Current source terminal in common-emitter configuration	Connected to load (e.g., LED anode or logic gate input); V_CE(SAT) ≤ 0.3 V at I_C/I_B = 10 ensures low conduction loss.

Key Features

Feature	Design Value
Complementary PNP pairing	MMBT3906 available with matched V_CEO, h_FE, and switching specs for push-pull output stages.
Epitaxial planar die construction	Enables tight parameter distribution (e.g., h_FE binning) and stable f_T across temperature (-55°C to +150°C).
Low V_CE(SAT)	≤0.3 V at I_C = 50 mA, I_B = 5 mA - reduces power loss in saturated-switch applications like level translation.
High f_T / low C_obo	300 MHz f_T with 4.0 pF C_obo - supports RF preamp use up to 50 MHz without external neutralization.

Applications

Logic-Level Signal Switching

Sensor Interface Amplification

Use Scenario: Driving 5 V TTL inputs or enabling/disabling pull-up networks in microcontroller GPIO expansion.

IC Role / Device Role: NPN switch operating in saturation/cutoff with base driven by 3.3 V MCU output through current-limiting resistor.

Use Value: V_CE(SAT) ≤ 0.3 V ensures <10 mW dissipation at 20 mA load, minimizing self-heating during sustained ON states.

Use Scenario: Amplifying low-amplitude analog signals from thermistors or photodiodes before ADC sampling.

IC Role / Device Role: Common-emitter small-signal amplifier biased at I_C = 1 mA, V_CE = 5 V for linearity and noise performance.

Use Value: NF = 5.0 dB at I_C = 100 µA and RS = 1 kΩ enables sub-10 µV input-referred noise in precision front-ends.

PWM-Controlled LED Bias

Level Translation (3.3 V ↔ 5 V)

Use Scenario: Modulating current through high-brightness LEDs using 1–10 kHz PWM from an embedded controller.

IC Role / Device Role: Fast-switching NPN current sink with t_r/t_f ≤ 35/50 ns and t_s = 200 ns to minimize duty-cycle distortion.

Use Value: Consistent t_s ensures accurate PWM edge timing across temperature, critical for color-mixing accuracy in RGB LED systems.

Use Scenario: Interfacing 3.3 V FPGA I/O to legacy 5 V peripheral buses requiring unidirectional voltage shift.

IC Role / Device Role: Single-transistor level shifter with emitter follower or common-emitter topology depending on directionality.

Use Value: h_FE ≥ 100 at I_C = 1 mA guarantees reliable turn-on with weak 3.3 V drive, eliminating need for external bias resistors.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC847BW,115	V_CEO = 45 V, h_FE = 200–450 (I_C = 10 mA), R_JA = 300 K/W	Higher h_FE spread and lower thermal resistance enable tighter base drive control in low-power amplifiers.	Select when higher DC gain consistency or improved thermal performance is required at same SOT-23 footprint.
PN2222A-AP	V_CEO = 40 V, I_C = 600 mA, P_D = 1 W, TO-92 package	Higher current/power rating but through-hole only; not drop-in compatible due to package mismatch.	Choose only if board redesign allows TO-92 mounting and >200 mA peak current is needed.

Compared with BC847BW and PN2222A-AP, the MMBT3904-13 offers optimal balance of SOT-23 manufacturability, 200 mA capability, and 300 MHz f_T for space-constrained digital and analog signal paths where thermal budget is moderate and lead-free reflow compatibility is mandatory.

Availability

MMBT3904-13 is available at Aetrix Electronics and suitable for logic-level signal switching, sensor interface amplification, and PWM-controlled LED bias applications requiring stable component supply and full RoHS compliance.

Supply support for MMBT3904-13 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability, cost-optimized components for consumer, industrial, and computing markets.

The MMBT3904-13 belongs to Diodes' broad portfolio of small-signal transistors designed for high-volume, space-sensitive applications including portable electronics, IoT sensor nodes, and automotive body-control modules.

FAQ

What is the maximum allowable junction temperature for MMBT3904-13?

The absolute maximum junction temperature is +150°C, with storage temperature also rated from –55°C to +150°C. Operation above +125°C requires derating I_C and P_D based on R_JA = 357 K/W and actual PCB copper area; no internal thermal shutdown is provided.

Can MMBT3904-13 be used in linear amplifier configurations?

Yes-it supports Class-A small-signal amplification with verified h_fe = 100–400 and NF = 5.0 dB at I_C = 100 µA. Stable biasing requires emitter degeneration and V_CE ≥ 1 V to avoid Early effect distortion; f_T = 300 MHz permits bandwidth up to ~50 MHz with gain ≤10.

Is MMBT3904-13 pin-compatible with other SOT-23 NPN transistors?

Yes-its pinout (Emitter-Base-Collector on pins 1-2-3) conforms to JEDEC standard SOT-23 layout. However, electrical parameters (e.g., h_FE, V_CE(SAT), f_T) differ across manufacturers; direct substitution requires verification against target circuit's gain, speed, and thermal requirements.

Does MMBT3904-13 have qualified AEC-Q101 automotive grade variants?

No-the standard MMBT3904-13 is not AEC-Q101 qualified. Diodes Incorporated offers the MMBT3904Q-13 as the automotive-grade version, featuring extended temperature testing (–40°C to +125°C), enhanced process controls, and PPAP documentation for automotive applications.

MMBT3904-13 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

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

Packaging:: Tape & Reel (TR)

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 (ICBO)

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

Power - Max:: 310 mW

Frequency - Transition:: 300MHz

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

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

MMBT3904-13 FAQ

1.How can I place an order for MMBT3904-13 through Aetrix?

Please submit a Request for Quotation (RFQ) for MMBT3904-13 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 MMBT3904-13 reliable?

The price and inventory of MMBT3904-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MMBT3904-13 is usually 5 days.

3.What payment methods are accepted for MMBT3904-13?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MMBT3904-13 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MMBT3904-13?

MMBT3904-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MMBT3904-13 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 MMBT3904-13?

For technical support, including MMBT3904-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MMBT3904-13 requirements.

6.How does Aetrix verify that MMBT3904-13 is sourced from the original manufacturer or authorized distributors?

All MMBT3904-13 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 MMBT3904-13 meets industry standards.

7.What is the process for return or replacement of MMBT3904-13?

All MMBT3904-13 units undergo pre-shipment inspection (PSI). If there is an issue with MMBT3904-13, 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 MMBT3904-13 part is unused and in its original packaging.

Return procedure for MMBT3904-13:

1.Submit a request within 90 days.

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

Tech Hub

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…

2026-08-11 LDO Regulator: Dropout Voltage, Noise, PSRR and Power Dissipation

LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…

2026-08-06 Conditional Access Module: CAM, CI/CI+ and DVB Security

Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…

2026-08-03 Electronic Component Obsolescence: EOL Risks, Replacement Options and Last-Time Buy Strategy

Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.

2026-07-29 18650 Battery: Voltage, Capacity, Charging and Pack Design

18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…

2026-07-27 Hall Effect Sensor: Working Principle, Types, Circuits and Applications

Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…

2026-07-20 Product Change Notification (PCN) in Electronic Components: Meaning and Supply Chain Response

Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…

2026-07-19 Blend Door Actuator: Symptoms, Location, Reset and Replacement Guide

A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…