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

Nexperia USA Inc. PMBT3904-QR

Name: PMBT3904-QR
Brand: Nexperia USA Inc.
SKU: PMBT3904-QR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: PMBT3904-QR

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

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

Datasheet:: PMBT3904-QR.pdf

Description:: TRANS NPN 40V 0.2A TO-236AB

Quantity:: RFQ Add To RFQ list

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Product details

Overview

PMBT3904-QR from Nexperia is an AEC-Q101-qualified NPN bipolar junction transistor in SOT23 package, rated for 40 V V_CEO, 200 mA I_C, and DC current gain (h_FE) of 100–300 at I_C = 10 mA. It serves as a general-purpose switching device in automotive power control circuits, load drivers, and signal-level amplification stages where robust thermal performance and automotive-grade reliability are required.

For engineers reviewing the PMBT3904-QR datasheet, PMBT3904-QR pinout, PMBT3904-QR application, or PMBT3904-QR equivalent, key selection criteria include its 40 V breakdown rating, 250 mW power dissipation at T_amb ≤ 25 °C, 500 K/W junction-to-ambient thermal resistance, and validated operation across −65 °C to +150 °C ambient range.

Technical Context

This discrete NPN transistor operates in active or saturation mode with base-driven control logic. Its h_FE spans 30–300 depending on collector current (10 mA to 100 mA) and temperature (−55 °C to +150 °C), enabling predictable gain-based biasing in linear and switching configurations.

Switching performance is characterized by t_d/t_r/t_s/t_f ≤ 35 ns / 35 ns / 200 ns / 50 ns under defined test conditions (I_Bon = 1 mA, I_Boff = −1 mA), and V_CEsat remains ≤ 850 mV at I_C = 10 mA / I_B = 1 mA, supporting low-loss on-state operation in digital interface and relay-driving applications.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum safe collector-emitter voltage with base open; defines upper rail limit in switching topologies.
I_C	200 mA - Continuous collector current rating; supports medium-current loads like LED strings or small solenoids.
h_FE	100–300 at V_CE = 1 V, I_C = 10 mA, T_amb = 25 °C - Enables stable base-resistor biasing for predictable switching thresholds.
V_CEsat	≤ 850 mV at I_C = 10 mA, I_B = 1 mA - Ensures low conduction loss and minimal self-heating during sustained on-state operation.
R_th(j-a)	500 K/W - Thermal resistance when mounted on FR4 PCB with single-sided copper; informs heatsinking requirements for continuous duty.
T_j max	150 °C - Maximum junction temperature; sets absolute thermal ceiling for reliability under worst-case power dissipation.

Pinout & Package

SOT23 plastic surface-mount package: 3-terminal, 1.9 mm pitch, 2.9 mm × 1.3 mm × 1.0 mm body. Standard footprint compatible with reflow and wave soldering per Figures 9 and 10 in the datasheet.

Pin/Terminal	Circuit Role	Design Meaning
1	Base (B)	Current-controlled input node; requires external resistor to limit I_B ≤ 100 mA peak for safe drive.
2	Emitter (E)	Common reference terminal; connected to ground or low-side return path in low-side switch configurations.
3	Collector (C)	Output current sink node; interfaces with load (e.g., relay coil, LED anode) tied to positive supply rail.

Key Features

Feature	Design Value
AEC-Q101 qualified	Validated for automotive use per stress-test standard; supports deployment in engine control, body electronics, and ADAS subsystems without additional qualification.
V_CBO = 60 V	Higher collector-base breakdown than V_CEO; allows safe operation with inductive kickback in relay or motor driver circuits.
Low V_BEsat ≤ 950 mV	Reduces base drive power and eases compatibility with 3.3 V or 5 V microcontroller GPIO outputs.
Fast switching (t_f ≤ 50 ns)	Enables PWM frequencies up to ~1 MHz in low-power DC-DC feedback or LED dimming applications.

Applications

Automotive Door Module Control

Industrial Sensor Interface Buffer

Use Scenario: Driving window lift motor relays and door lock actuators in 12 V vehicle architectures.

IC Role / Device Role / Timing Role: Low-side switch controlling inductive loads with flyback protection via integrated clamp diodes in system design.

Use Value: AEC-Q101 qualification ensures 15-year field reliability; 40 V V_CEO accommodates load dump transients up to 35 V.

Use Scenario: Level-shifting and buffering analog sensor outputs (e.g., thermistor, pressure bridge) into ADC inputs of PLC controllers.

IC Role / Device Role / Timing Role: Emitter-follower amplifier providing unity-gain buffering with low output impedance and high input impedance.

Use Value: h_FE ≥ 100 at 10 mA enables stable biasing with minimal base current draw, preserving sensor excitation accuracy.

Consumer Appliance Power Sequencing

Medical Diagnostic Equipment Signal Switching

Use Scenario: Enabling/disabling auxiliary power rails (e.g., display backlight, fan control) in smart home hubs and HVAC controllers.

IC Role / Device Role / Timing Role: Digital on/off switch controlled by MCU GPIO, interfacing with 5 V or 3.3 V logic levels.

Use Value: V_CEsat ≤ 850 mV at 10 mA limits power loss to <10 mW, eliminating need for heatsinking in compact enclosures.

Use Scenario: Multiplexing analog signals from multiple biosensors (ECG, SpO₂) into shared acquisition channels.

IC Role / Device Role / Timing Role: Fast-switching transistor used in analog multiplexer front-end to isolate signal paths during channel selection.

Use Value: t_f ≤ 50 ns ensures clean channel transitions with <100 ns dead time, preventing cross-talk in sub-millisecond sampling windows.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC847BW-Q	Same SOT23 package, but PNP polarity; h_FE 110–800, V_CEO = 45 V, I_C = 100 mA	Requires circuit redesign for high-side switching or complementary pair use; lower I_C limits load capability	Select only if PNP topology or tighter h_FE tolerance is needed; not a drop-in replacement
MMBT3904LT1G	Non-automotive grade; same electrical specs but no AEC-Q101 qualification; R_th(j-a) = 400 K/W (slightly better thermal performance)	Not approved for automotive safety-critical modules; suitable for industrial or consumer systems with less stringent reliability requirements	Prefer for cost-sensitive non-automotive designs where qualification overhead is unnecessary

Compared with BC847BW-Q and MMBT3904LT1G, PMBT3904-QR uniquely combines AEC-Q101 compliance, 200 mA I_C, and 40 V V_CEO in SOT23-making it the only choice for automotive-grade medium-current switching where qualification and margin are mandatory.

Availability

PMBT3904-QR is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor interfaces, and consumer appliance power sequencing requiring stable component supply and long-term lifecycle support.

Supply support for PMBT3904-QR 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 high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified components and advanced packaging technologies.

The PMBT3904-QR belongs to Nexperia's AEC-Q101-qualified general-purpose transistor product line, engineered specifically for robust, cost-effective switching and amplification in harsh-environment automotive and industrial control systems.

FAQ

Is PMBT3904-QR pin-compatible with the standard PMBT3904?

Yes, PMBT3904-QR shares identical SOT23 pinout (1 = Base, 2 = Emitter, 3 = Collector) and mechanical footprint with the non-automotive PMBT3904. Electrical specifications are aligned, but PMBT3904-QR adds AEC-Q101 qualification and tighter process controls for automotive use.

What is the maximum allowable base current for continuous operation?

The absolute maximum peak base current is 100 mA per datasheet Table 5. For continuous DC operation, design must ensure I_B ≤ 20 mA to maintain junction temperature below 150 °C under typical PCB mounting conditions, given P_tot = 250 mW and V_BEsat ≈ 0.7–0.95 V.

Can PMBT3904-QR be used in linear amplifier configurations?

Yes-it supports linear operation with h_FE specified from 30 to 300 across I_C = 0.1 mA to 100 mA and temperatures from −55 °C to +150 °C. However, thermal derating is required above 25 °C ambient due to R_th(j-a) = 500 K/W; gain stability improves with emitter degeneration resistors.

Does PMBT3904-QR require external flyback protection when driving inductive loads?

No internal flyback diode is integrated. When switching relays or solenoids, an external reverse-biased diode (e.g., 1N4148) must be placed across the load to clamp V_CE spikes exceeding 40 V, preventing breakdown. This is standard practice for all discrete BJTs in inductive switching roles.

PMBT3904-QR Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

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

Packaging:: Tape & Reel (TR)

Product Status:: Active

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:: 250 mW

Frequency - Transition:: 300MHz

Operating Temperature:: 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: TO-236AB

PMBT3904-QR FAQ

1.How can I place an order for PMBT3904-QR through Aetrix?

Please submit a Request for Quotation (RFQ) for PMBT3904-QR 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 PMBT3904-QR reliable?

The price and inventory of PMBT3904-QR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PMBT3904-QR is usually 5 days.

3.What payment methods are accepted for PMBT3904-QR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PMBT3904-QR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for PMBT3904-QR?

PMBT3904-QR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your PMBT3904-QR 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 PMBT3904-QR?

For technical support, including PMBT3904-QR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PMBT3904-QR requirements.

6.How does Aetrix verify that PMBT3904-QR is sourced from the original manufacturer or authorized distributors?

All PMBT3904-QR 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 PMBT3904-QR meets industry standards.

7.What is the process for return or replacement of PMBT3904-QR?

All PMBT3904-QR units undergo pre-shipment inspection (PSI). If there is an issue with PMBT3904-QR, 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 PMBT3904-QR part is unused and in its original packaging.

Return procedure for PMBT3904-QR:

1.Submit a request within 90 days.

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

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