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

Nexperia USA Inc. BC817-40W/ZLX

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

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Part No.:: BC817-40W/ZLX

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

Package:: SC-70, SOT-323

Datasheet:: BC817-40W/ZLX.pdf

Description:: TRANS PNP 45V SOT323

Quantity:: RFQ Add To RFQ list

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Product details

Overview

BC817-40W/ZLX from Nexperia is a 45 V, 500 mA NPN general-purpose transistor in SOT323 (SC-70) package, optimized for low-power switching and linear amplification with h_FE = 250–600 at V_CE = 1 V, I_C = 100 mA, and T_amb = 25 °C. It delivers reliable performance in space-constrained consumer and industrial signal-path circuits.

For engineers reviewing the BC817-40W/ZLX datasheet, BC817-40W/ZLX pinout, BC817-40W/ZLX application, or BC817-40W/ZLX equivalent, this page provides verified pin functions, thermal derating behavior, saturation voltage under defined drive conditions, current gain distribution across operating range, and validated alternative transistors for design flexibility.

Technical Context

The BC817-40W/ZLX operates as a discrete NPN bipolar junction transistor with fixed emitter-base and collector-base junctions, supporting both active-mode amplification and saturated-switching operation. Its h_FE range (250–600) enables predictable base-current sizing for load-driving applications up to 500 mA DC.

Thermal performance is defined by R_th(j-a) = 625 K/W on standard FR4 PCB and 431 K/W with extended collector pad, while V_CE(sat) ≤ 700 mV at I_C = 500 mA and I_B = 50 mA ensures low conduction loss in switching configurations.

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	45 V - Maximum safe collector-emitter voltage before breakdown under open-base condition.
I_C	500 mA - Continuous collector current rating defining maximum steady-state load drive capability.
h_FE	250–600 - DC current gain at V_CE = 1 V, I_C = 100 mA, enabling precise base biasing for gain-stable amplification or switching.
V_CE(sat)	≤ 700 mV - Collector-emitter saturation voltage at I_C = 500 mA, I_B = 50 mA, limiting power dissipation during on-state operation.
f_T	100 MHz - Transition frequency at V_CE = 5 V, I_C = 10 mA, supporting audio and low-MHz signal amplification.
R_th(j-a)	625 K/W - Junction-to-ambient thermal resistance on standard FR4 PCB, informing heatsinking requirements for continuous operation.

Pinout & Package

SOT323 (SC-70) plastic surface-mounted package with 3 leads, footprint dimensions per Figure 17 (reflow) and Figure 18 (wave), total package size 2.2 mm × 1.35 mm × 0.95 mm (L × W × H).

Pin/Terminal	Circuit Role	Design Meaning
1	Base (B)	Control terminal; requires current-limited drive to achieve target h_FE-based collector current.
2	Emitter (E)	Reference terminal for bias network; connected to ground or common return path in most configurations.
3	Collector (C)	Output terminal; carries full load current and dissipates power during saturation or active operation.

Key Features

Feature	Design Value
Three h_FE selections	BC817-40W offers 250–600 h_FE, enabling consistent gain binning for production repeatability in amplifier and switch designs.
Low V_CE(sat)	700 mV max at 500 mA/50 mA ensures <1.5× power loss vs. higher-saturation alternatives in battery-powered switching nodes.
Small-footprint SOT323	0.95 mm height and 2.2 mm × 1.35 mm footprint supports high-density PCB layouts in portable electronics.
150 °C max junction temperature	Enables operation in thermally demanding environments such as enclosed industrial control modules without forced cooling.

Applications

LED Driver Circuit

Microcontroller GPIO Expander

Use Scenario: Driving 20 mA indicator LEDs from 3.3 V microcontroller outputs with current-limiting resistor.

IC Role / Device Role / Timing Role: NPN switch controlling LED anode current path; base driven directly from MCU GPIO.

Use Value: V_CE(sat) ≤ 700 mV ensures >2.6 V forward voltage remains across LED for stable brightness at full current.

Use Scenario: Amplifying weak analog sensor signals (e.g., thermistor divider output) before ADC sampling.

IC Role / Device Role / Timing Role: Common-emitter amplifier stage providing 10–20× voltage gain with minimal distortion.

Use Value: f_T = 100 MHz and h_FE = 250–600 support bandwidth up to 100 kHz with <1% THD at 1 V_PP.

Power Supply Enable Switch

Level Translation Interface

Use Scenario: Enabling/disabling 5 V rail to peripheral ICs using 1.8 V logic-level control signal.

IC Role / Device Role / Timing Role: Low-side switch connecting peripheral V_CC to ground when enabled.

Use Value: I_C = 500 mA rating accommodates peak inrush of multiple peripherals; h_FE bin ensures predictable turn-on delay <1 µs.

Use Scenario: Translating 1.8 V logic-high to 5 V logic-high for legacy interface compatibility.

IC Role / Device Role / Timing Role: Emitter-follower buffer with base tied to 1.8 V source and emitter outputting ~1.1 V, used in open-collector pull-up configuration.

Use Value: V_BE ≈ 1.2 V at I_C = 500 mA allows clean 5 V logic-high generation with <10 ns propagation delay.

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
BC847BW	Lower V_CEO = 45 V (same), but h_FE = 200–450 and I_C = 100 mA - reduced current handling.	Not suitable for 500 mA loads; limited to signal-level switching and pre-amplification.	Select when board space is identical but load current ≤ 100 mA and tighter h_FE tolerance required.
MMBT3904LT1G	Same SOT23 package (not SOT323), V_CEO = 40 V, h_FE = 100–300, I_C = 200 mA - lower voltage, current, and gain.	Requires PCB footprint redesign; unsuitable for 45 V rails or >200 mA loads.	Choose only if SOT23 is already standardized in design and performance margins allow de-rating.

Compared with BC817-40W/ZLX, BC847BW trades current capacity for tighter h_FE spread in same footprint, while MMBT3904LT1G sacrifices voltage headroom and thermal margin for broader distributor availability - neither matches its 500 mA/45 V/250–600 h_FE combination in SOT323.

Availability

BC817-40W/ZLX is available at Aetrix Electronics and suitable for LED driver circuits, microcontroller GPIO expansion, and power supply enable switches requiring stable component supply, consistent h_FE binning, and SOT323 footprint compatibility.

Supply support for BC817-40W/ZLX 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, serving automotive, industrial, and consumer markets with ISO/TS 16949-certified manufacturing.

The BC817W series targets cost-sensitive, space-constrained applications needing robust general-purpose NPN transistors with guaranteed h_FE bins and industry-standard SOT323 packaging.

FAQ

What is the maximum allowable base current for continuous operation?

The absolute maximum peak base current is 200 mA per Table 6, but for continuous DC operation, base current must be sized to maintain I_C ≤ 500 mA within the device's thermal limits. At I_C = 500 mA and minimum h_FE = 250, I_B ≥ 2 mA is required; typical design uses 5–10 mA to ensure saturation across temperature and process variation.

Does BC817-40W/ZLX support automotive applications?

No - the BC817W series is explicitly non-automotive qualified per Revision History section 13, which states "Product changed to non-automotive qualification" in v.8 (2022). Automotive-grade alternatives (e.g., BC817-40W-Q) require separate part numbers and qualification testing per AEC-Q101.

How does thermal derating affect maximum power dissipation at 70 °C ambient?

At T_amb = 70 °C, P_tot derates linearly from 290 mW at 25 °C (per Table 6 footnote [3]) using R_th(j-a) = 431 K/W. Junction temperature must stay ≤150 °C, so ΔT = 80 K allows P_tot = 80 K ÷ 431 K/W ≈ 186 mW - confirming usable power drops by 36% at 70 °C ambient.

Can BC817-40W/ZLX replace BC817-25W in existing designs?

Yes - both share identical SOT323 package, pinout, and absolute maximum ratings; only h_FE range differs (250–600 vs. 160–400). Substitution improves gain margin and reduces base drive requirements, but may increase sensitivity to leakage currents in high-impedance bias networks.

BC817-40W/ZLX Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

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

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Transistor Type:: -

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

Voltage - Collector Emitter Breakdown (Max):: -

Vce Saturation (Max) @ Ib, Ic:: -

Current - Collector Cutoff (Max):: -

DC Current Gain (hFE) (Min) @ Ic, Vce:: -

Power - Max:: -

Frequency - Transition:: -

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-323

BC817-40W/ZLX FAQ

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

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

The price and inventory of BC817-40W/ZLX 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/ZLX is usually 5 days.

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

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

Note: Certain payment methods may incur a processing fee.

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

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

Once your BC817-40W/ZLX 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/ZLX?

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

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

All BC817-40W/ZLX 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/ZLX meets industry standards.

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

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

Return procedure for BC817-40W/ZLX:

1.Submit a request within 90 days.

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

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