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

Infineon Technologies SMBT 3904 B5003

Name: SMBT 3904 B5003
Brand: Infineon Technologies
SKU: SMBT 3904 B5003
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: SMBT 3904 B5003

Manufacturer:: Infineon Technologies

Category:: Single Bipolar Transistors

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

Datasheet:: SMBT 3904 B5003.pdf

Description:: TRANS NPN 40V 0.2A PG-SOT23

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:8,882

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

Product details

Overview

SMBT3904 B5003 from Nexperia is an NPN silicon switching transistor in SOT23 package, rated for 40 V V_CEO, 200 mA I_C, and 330 mW P_tot at T_S ≤ 71°C. It delivers high DC current gain (h_FE = 100 min at I_C = 10 mA), low V_CE(sat) (0.2 V typ at I_C/I_B = 10 mA/1 mA), and f_T = 300 MHz - used in discrete logic-level switching, LED drivers, and small-signal amplification stages of automotive body control modules.

For engineers reviewing the SMBT3904 B5003 datasheet, SMBT3904 B5003 pinout, SMBT3904 B5003 application, or SMBT3904 B5003 equivalent, key selection criteria include verified V_CE(sat) performance under 10–50 mA load conditions, thermal resistance R_thJS ≤ 240 K/W, AEC-Q101 qualification status, and SOT23 footprint compatibility with legacy 3904-based designs.

Technical Context

This device operates as a general-purpose NPN bipolar junction transistor optimized for linear amplification and saturated switching. Its h_FE spans 40–300 across I_C = 100 µA to 100 mA, with guaranteed minimum gain at low currents (h_FE ≥ 70 at I_C = 1 mA) and stable saturation behavior (V_CE(sat) ≤ 0.3 V at I_C/I_B = 50 mA/5 mA).

Designed for robustness in automotive environments, it meets AEC-Q101 stress testing requirements and features Pb-free RoHS-compliant packaging. The SOT23 footprint supports automated placement, while its 150°C maximum junction temperature enables operation in engine bay–adjacent control units without derating below 71°C board temperature.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Supports 36 V automotive battery systems with margin for load dump transients.
I_C	200 mA - Handles relay coil drive, indicator LED strings, and sensor interface biasing.
h_FE @ I_C=10 mA	100 min - Ensures reliable base drive margin for digital switching with 1 kΩ pull-up.
V_CE(sat) @ I_C/I_B=10 mA/1 mA	0.2 V typ - Minimizes power loss and self-heating in always-on bias networks.
f_T	300 MHz - Enables use in low-frequency RF preamps and fast-switching PWM modulators.
R_thJS	≤240 K/W - Allows direct thermal path design from die to PCB copper in space-constrained SMT layouts.
AEC-Q101 Qualified	Yes - Validated for automotive electronics per stress test standard including HTOL, TC, and ESD.

Pinout & Package

Package: SOT23 - Surface-mount plastic package with 3-pin configuration, 1.3 mm × 2.9 mm footprint, 1.1 mm height, and gull-wing leads compatible with IPC-7351B density level A.

Pin/Terminal	Circuit Role	Design Meaning
1 (Emitter)	E	Current sink node; connected to ground or low-side return path in switch configurations.
2 (Base)	B	Control input; requires ~0.7 V forward bias and sufficient I_B to saturate at target I_C.
3 (Collector)	C	Current source node; tied to load supply rail in low-side switching topologies.

Key Features

Feature	Design Value
High h_FE consistency	h_FE ≥ 70 at I_C = 1 mA ensures predictable turn-on with weak MCU GPIO drive.
Low V_CE(sat)	0.2 V typical at 10 mA reduces conduction loss by >60% vs. standard 3904 variants.
AEC-Q101 qualification	Validated for automotive underhood applications including BCM, lighting, and HVAC actuators.
Pb-free & RoHS compliant	Meets EU Directive 2011/65/EU; compatible with lead-free reflow profiles (peak 260°C).

Applications

Automotive Body Control Module

Industrial Sensor Interface

Use Scenario: Driving 12 V incandescent bulbs and solenoid valves in door lock/unlock circuits.

IC Role / Device Role / Timing Role: Low-side switch controlling load current up to 150 mA with <1 µs turn-off delay.

Use Value: V_CE(sat) ≤ 0.3 V prevents thermal runaway during continuous 100 mA duty cycles.

Use Scenario: Level-shifting and buffering analog sensor outputs (e.g., thermistor voltage dividers) into ADC inputs.

IC Role / Device Role / Timing Role: Emitter-follower buffer providing high input impedance and low output impedance.

Use Value: h_FE ≥ 100 at 100 µA ensures stable biasing without loading sensitive resistive sensors.

LED Driver for Status Indicators

Discrete Logic Inverter

Use Scenario: Switching 20 mA red/green LEDs on industrial HMI panels with 3.3 V microcontroller I/O.

IC Role / Device Role / Timing Role: Saturated switch operating in cutoff/saturation modes with <35 ns rise/fall times.

Use Value: f_T = 300 MHz supports clean edge transitions even with capacitive PCB traces.

Use Scenario: Implementing non-inverting logic gates in repair scenarios where gate ICs are unavailable.

IC Role / Device Role / Timing Role: Common-emitter amplifier with fixed bias network delivering digital inversion.

Use Value: Guaranteed h_FE ≥ 40 at I_C = 100 µA ensures noise-immune logic thresholds at 5 V supply.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMBT3904-7-F (Diodes Inc.)	V_CE(sat) = 0.3 V max at I_C/I_B = 50 mA/5 mA; h_FE = 100–300 (same range); R_thJS = 300 K/W.	Higher thermal resistance limits sustained 100 mA operation on minimal copper.	Select when cost sensitivity outweighs thermal margin; verify layout copper area.
BC846B,215 (Nexperia)	V_CEO = 65 V; h_FE = 200–450 at I_C = 10 mA; same SOT23 package and pinout.	Higher voltage rating adds overvoltage headroom but increases V_BE(sat) by ~50 mV.	Choose for 48 V systems or where higher gain stability at low I_C is critical.

Compared with MMBT3904-7-F, SMBT3904 B5003 offers lower thermal resistance and tighter V_CE(sat) control; versus BC846B,215, it trades higher voltage capability for lower V_BE(sat) and proven AEC-Q101 compliance in production automotive programs.

Availability

SMBT3904 B5003 is available at Aetrix Electronics and suitable for automotive body control modules, industrial sensor interfaces, LED status indicators, and discrete logic inverters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SMBT3904 B5003 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

Nexperia is a global semiconductor expert focused on essential semiconductors, delivering high-performance, reliable components for automotive, industrial, and consumer markets.

The SMBT3904 series belongs to Nexperia's Automotive-Qualified General Purpose Transistors product line, engineered specifically for robust discrete switching and amplification in harsh-environment electronic control units.

FAQ

Is SMBT3904 B5003 pin-compatible with standard MMBT3904 devices?

Yes - SMBT3904 B5003 uses the same SOT23 package and identical pinout (E-B-C) as industry-standard MMBT3904 transistors. Mechanical dimensions, solder pad layout, and thermal pad absence match IPC-7351B SOT23A, enabling drop-in replacement without PCB redesign.

What is the maximum continuous collector current at 105°C ambient?

At T_A = 105°C, derating applies: P_tot drops to ~120 mW (from 330 mW at 71°C), limiting I_C to approximately 110 mA assuming V_CE = 1.1 V. Full 200 mA rating is only valid at T_S ≤ 71°C per datasheet thermal curves.

Does SMBT3904 B5003 support pulsed operation beyond its DC ratings?

Yes - pulse operation up to 500 mA is permissible with duty cycle ≤ 2% and pulse width ≤ 300 µs, as confirmed by the permissible pulse load curve (P_tot(max)/P_tot(DC) = 5 at t_p = 100 µs). Thermal transient response must be validated per AN077.

How does AEC-Q101 qualification impact reliability in non-automotive applications?

AEC-Q101 qualification subjects SMBT3904 B5003 to accelerated stress tests (HTOL, TC, ESD) exceeding industrial standards. This yields >10× longer FIT rate and improved parametric stability in 24/7 industrial equipment, even when deployed outside automotive contexts.

SMBT 3904 B5003 Specifications

Product attributes: Attribute value

Manufacturer:: Infineon Technologies

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:: 330 mW

Frequency - Transition:: 300MHz

Operating Temperature:: 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: PG-SOT23

SMBT 3904 B5003 FAQ

1.How can I place an order for SMBT 3904 B5003 through Aetrix?

Please submit a Request for Quotation (RFQ) for SMBT 3904 B5003 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 SMBT 3904 B5003 reliable?

The price and inventory of SMBT 3904 B5003 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SMBT 3904 B5003 is usually 5 days.

3.What payment methods are accepted for SMBT 3904 B5003?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SMBT 3904 B5003 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for SMBT 3904 B5003?

SMBT 3904 B5003 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your SMBT 3904 B5003 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 SMBT 3904 B5003?

For technical support, including SMBT 3904 B5003 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SMBT 3904 B5003 requirements.

6.How does Aetrix verify that SMBT 3904 B5003 is sourced from the original manufacturer or authorized distributors?

All SMBT 3904 B5003 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 SMBT 3904 B5003 meets industry standards.

7.What is the process for return or replacement of SMBT 3904 B5003?

All SMBT 3904 B5003 units undergo pre-shipment inspection (PSI). If there is an issue with SMBT 3904 B5003, 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 SMBT 3904 B5003 part is unused and in its original packaging.

Return procedure for SMBT 3904 B5003:

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…