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

Nexperia USA Inc. BC817-40W-QF

Name: BC817-40W-QF
Brand: Nexperia USA Inc.
SKU: BC817-40W-QF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: BC817-40W-QF

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

Package:: SC-70, SOT-323

Datasheet:: BC817-40W-QF.pdf

Description:: TRANS NPN 45V 0.5A SOT-323

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Product details

Overview

BC817-40W-QF from Nexperia is an AEC-Q101-qualified NPN general-purpose transistor in SOT323 (SC-70) package, rated for 45 V V_CEO, 500 mA I_C, and DC current gain (h_FE) of 250–600 at V_CE = 1 V and I_C = 100 mA. It serves as a robust switching and amplification device in automotive power management, LED driver stages, and sensor interface circuits.

For engineers reviewing the BC817-40W-QF datasheet, BC817-40W-QF pinout, BC817-40W-QF application, or BC817-40W-QF equivalent, this page delivers verified electrical parameters, thermal derating behavior, automotive qualification status, and real-world use context - all confirmed against Nexperia's official Rev. 1 (June 2021) product data sheet.

Technical Context

This transistor operates as a silicon NPN bipolar junction device with base-controlled current amplification. Its h_FE range (250–600) enables stable biasing across temperature (−55 °C to 150 °C), while V_CE(sat) ≤ 700 mV at I_C = 500 mA / I_B = 50 mA ensures low conduction loss in switching applications.

Thermal resistance R_th(j-a) is 431 K/W when mounted on FR4 PCB with 1 cm² collector pad, supporting sustained operation up to 150 °C junction temperature. The device meets AEC-Q101 stress test requirements for automotive discrete semiconductors, including HTRB, HTGB, and temperature cycling.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum safe collector-emitter voltage under open-base condition; defines upper rail limit in 12 V/24 V automotive switching designs.
I_C	500 mA continuous - Rated collector current at 25 °C ambient; supports medium-power load switching without forced cooling.
h_FE	250–600 at V_CE = 1 V, I_C = 100 mA - High and tightly binned DC current gain enables predictable base drive sizing and stable amplifier biasing.
V_CE(sat)	≤ 700 mV at I_C = 500 mA, I_B = 50 mA - Low saturation voltage minimizes power dissipation and heat generation during on-state operation.
P_tot	290 mW at T_amb ≤ 25 °C with 1 cm² collector pad - Thermal performance allows direct integration into space-constrained automotive PCBs without heatsinking.
f_T	100 MHz - Transition frequency supports high-speed switching up to ~10 MHz with adequate gain margin, suitable for PWM-driven loads.
R_th(j-a)	431 K/W - Junction-to-ambient thermal resistance with optimized PCB layout; enables accurate thermal modeling for reliability validation.

Pinout & Package

SOT323 (SC-70) plastic surface-mounted package: ultra-compact 3-lead footprint (2.2 mm × 1.35 mm × 0.95 mm), optimized for high-density automotive PCB assembly and reflow soldering.

Pin/Terminal	Circuit Role	Design Meaning
1	Base (B)	Current-controlled input node; requires 1.2 V forward bias and ~12 mA drive for full saturation at 500 mA collector current.
2	Emitter (E)	Common reference terminal; internally connected to substrate; must be tied to system ground or low-side return path.
3	Collector (C)	High-current output node; electrically isolated from package body; connects to load or supply rail in low-side switch configuration.

Key Features

Feature	Design Value
AEC-Q101 qualification	Validated for automotive underhood and cabin applications per stress test standard - eliminates need for customer-level qualification effort.
Three h_FE bins (16/25/40)	BC817-40W-Q offers highest gain bin (250–600), enabling reduced base drive current and lower MCU GPIO loading in battery-powered modules.
Low V_CE(sat)	700 mV max ensures <150 mW conduction loss at 500 mA, critical for thermally constrained ECUs and LED drivers.
SC-70 footprint compatibility	Standardized SOT323 land pattern (2.65 mm × 2.35 mm) enables drop-in replacement and automated placement with industry-standard pick-and-place equipment.
150 °C maximum junction temperature	Supports operation in engine control units and power distribution modules where ambient exceeds 105 °C.

Applications

Automotive Door Module

Industrial Sensor Interface

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

IC Role / Device Role / Timing Role: Low-side switch controlling inductive loads via MCU GPIO; handles 500 mA peak coil current with flyback protection.

Use Value: AEC-Q101 qualification ensures long-term reliability under vibration, thermal cycling, and load dump transients.

Use Scenario: Amplifying weak analog signals from RTD or thermistor bridges before ADC sampling.

IC Role / Device Role / Timing Role: Linear-mode NPN amplifier configured in common-emitter topology with fixed emitter degeneration.

Use Value: Tight h_FE bin (250–600) enables precise gain setting and stable DC operating point across −40 °C to 125 °C.

LED Driver Stage

Power Supply Enable Switch

Use Scenario: Switching 350 mA white LED strings in automotive interior lighting systems.

IC Role / Device Role / Timing Role: Constant-current switch modulated by PWM signal; operates in saturated region with minimal V_CE loss.

Use Value: V_CE(sat) ≤ 700 mV limits power dissipation to <250 mW, eliminating need for thermal relief on compact LED PCBs.

Use Scenario: Enabling/disabling auxiliary 5 V or 3.3 V LDO outputs in multi-rail power management ICs.

IC Role / Device Role / Timing Role: High-gain, low-leakage enable switch placed between LDO input and output to control rail sequencing.

Use Value: I_CBO ≤ 100 nA at 25 °C ensures negligible standby current leakage, preserving battery life in always-on modules.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN general-purpose transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BC817-40LT1G	Same h_FE bin (250–600) but SOT23 package; higher P_tot (350 mW) and larger footprint (2.9 mm × 1.3 mm).	Preferred where board space permits and higher power handling is needed; not AEC-Q101 qualified.	Select if thermal margin >40 mW is required and automotive qualification is not mandatory.
MMBT4401-7-F	Higher V_CEO (40 V vs. 45 V), same I_C (500 mA), but wider h_FE range (100–300); AEC-Q101 qualified.	Lower gain consistency reduces predictability in precision biasing; better suited for digital switching than analog amplification.	Choose when cost sensitivity outweighs gain stability needs and design tolerates ±50% h_FE variation.

Compared with BC817-40LT1G, BC817-40W-QF trades 60 mW higher power rating for 30% smaller footprint and guaranteed automotive qualification; versus MMBT4401-7-F, it delivers tighter h_FE control and 5 V higher breakdown - critical for 24 V system margin and analog accuracy.

Availability

BC817-40W-QF is available at Aetrix Electronics and suitable for automotive ECU modules, industrial sensor signal conditioning, and LED lighting control requiring stable component supply, AEC-Q101 compliance, and consistent h_FE performance.

Supply support for BC817-40W-QF 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 efficiency technologies, delivering high-performance logic, discrete, and MOSFET solutions for automotive, industrial, and consumer markets.

The BC817W-Q series belongs to Nexperia's AEC-Q101-qualified general-purpose transistor portfolio, engineered specifically for reliable switching and amplification in harsh automotive environments with extended temperature and lifetime requirements.

FAQ

Is BC817-40W-QF pin-compatible with BC817-25W-Q?

Yes - both share identical SOT323 (SC-70) package and pinout (1: Base, 2: Emitter, 3: Collector). The only difference is h_FE bin: BC817-40W-QF offers 250–600 versus BC817-25W-Q's 160–400. No PCB redesign is needed for substitution, though base resistor values may require adjustment to maintain optimal saturation.

What is the maximum allowable ambient temperature for continuous 500 mA operation?

At 500 mA I_C, power dissipation reaches ~350 mW (using V_CE(sat) = 700 mV). With R_th(j-a) = 431 K/W, junction temperature rise is ~151 °C - exceeding the 150 °C absolute max. Therefore, continuous 500 mA operation is only permissible below ~24 °C ambient, or with derating per Figure 1 in the datasheet.

Does BC817-40W-QF support wave soldering?

Yes - Nexperia provides dedicated wave soldering footprint (Fig. 18) with 3.65 mm × 2.1 mm pad layout and preferred transport direction. The SOT323 package is qualified for both reflow and wave processes, but wave soldering requires strict control of preheat ramp rate (<2 °C/s) and contact time (<3 s) to avoid delamination.

How does the marking "6C%" identify BC817-40W-QF on the device?

The top-side laser marking "6C%" uniquely identifies BC817-40W-QF: "6C" denotes the part variant (40W-Q gain bin), while "%" is a placeholder for the manufacturing site code (e.g., "A" for Nijmegen, "B" for Bangkok). This matches Table 5 in the datasheet and enables traceability to wafer lot and assembly batch.

BC817-40W-QF Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: BC817W-Q

Package/Case:: SC-70, SOT-323

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 500 mA

Voltage - Collector Emitter Breakdown (Max):: 45 V

Vce Saturation (Max) @ Ib, Ic:: 700mV @ 50mA, 500mA

Current - Collector Cutoff (Max):: 100nA (ICBO)

DC Current Gain (hFE) (Min) @ Ic, Vce:: 250 @ 100mA, 1V

Power - Max:: 200 mW

Frequency - Transition:: 100MHz

Operating Temperature:: 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-323

BC817-40W-QF FAQ

1.How can I place an order for BC817-40W-QF through Aetrix?

Please submit a Request for Quotation (RFQ) for BC817-40W-QF 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 BC817-40W-QF reliable?

The price and inventory of BC817-40W-QF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BC817-40W-QF is usually 5 days.

3.What payment methods are accepted for BC817-40W-QF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BC817-40W-QF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BC817-40W-QF?

BC817-40W-QF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BC817-40W-QF 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 BC817-40W-QF?

For technical support, including BC817-40W-QF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BC817-40W-QF requirements.

6.How does Aetrix verify that BC817-40W-QF is sourced from the original manufacturer or authorized distributors?

All BC817-40W-QF 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 BC817-40W-QF meets industry standards.

7.What is the process for return or replacement of BC817-40W-QF?

All BC817-40W-QF units undergo pre-shipment inspection (PSI). If there is an issue with BC817-40W-QF, 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 BC817-40W-QF part is unused and in its original packaging.

Return procedure for BC817-40W-QF:

1.Submit a request within 90 days.

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

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