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

Nexperia USA Inc. PBSS4540X-QF

Name: PBSS4540X-QF
Brand: Nexperia USA Inc.
SKU: PBSS4540X-QF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: PBSS4540X-QF

Manufacturer:: Nexperia USA Inc.

Category:: Single Bipolar Transistors

Package:: TO-243AA

Datasheet:: PBSS4540X-QF.pdf

Description:: TRANS NPN 40V 4A SOT-89

Quantity:: RFQ Add To RFQ list

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Product details

Overview

PBSS4540X-QF from Nexperia is a 40 V, 5 A NPN low V_CE(sat) transistor in SOT89 package, designed as a high-efficiency medium-power switch for automotive and industrial DC power control. It delivers R_CE(sat) = 40–71 mΩ at I_C = 5 A / I_B = 500 mA, h_FE ≥ 100 at full load, and is AEC-Q101 qualified for under-hood motor drivers and DC-DC converter primary-side switching.

For engineers reviewing the PBSS4540X-QF datasheet, PBSS4540X-QF pinout, PBSS4540X-QF application, or PBSS4540X-QF equivalent, this page provides verified technical context, thermal derating guidance, real-world use cases in fan/motor drive and battery charging circuits, and validated automotive-grade alternatives.

Technical Context

This NPN transistor operates with low saturation voltage (V_CE(sat) ≤ 355 mV at I_C = 5 A) and high DC current gain (h_FE ≥ 100), enabling efficient switching in medium-power linear and saturated-mode applications. Its 40 V V_CEO rating supports 24 V automotive systems and 36 V industrial rails.

Thermal performance is defined across multiple PCB mounting conditions: R_th(j-a) ranges from 50 K/W (standard FR4) to 80 K/W (ceramic PCB), while R_th(j-sp) = 16 K/W enables precise solder-point temperature estimation. Peak pulsed current capability reaches 10 A (t_p ≤ 10 ms).

Key Specifications

Parameter	Value and Actual Design Meaning
V_CEO	40 V - Maximum collector-emitter voltage before breakdown; supports 24 V automotive systems with 67 % safety margin.
I_C (continuous)	4 A - Continuous collector current rating; defines steady-state power handling in motor driver or charger switch stage.
R_CE(sat)	40–71 mΩ - Equivalent on-resistance at I_C = 5 A / I_B = 500 mA; determines conduction loss and self-heating in PWM operation.
h_FE	≥100 - DC current gain at I_C = 5 A; ensures reliable saturation with modest base drive (e.g., 50 mA MCU GPIO + buffer).
T_j(max)	150 °C - Maximum junction temperature; sets thermal design target for heatsinking and PCB copper area allocation.
P_tot (FR4, 6 cm² pad)	1.4 W - Total power dissipation limit with enhanced copper; enables ~350 mW continuous loss at 100 °C ambient.

Pinout & Package

SOT89 (SC-62/TO-243) plastic surface-mount package: 3-pin, 1.5 mm pitch, 4.5 mm × 2.5 mm × 1.5 mm body, with exposed collector tab for thermal conduction.

Pin/Terminal	Circuit Role	Design Meaning
1	Emitter	Current return path; connected to ground or low-side reference; requires low-inductance routing in switching applications.
2	Collector	Main power output terminal; electrically and thermally tied to large PCB copper pour for heat extraction and current carrying.
3	Base	Control input; driven by logic-level signal or dedicated driver; requires series resistor to limit I_B to ≤1 A peak.

Key Features

Feature	Design Value
AEC-Q101 qualification	Validated for automotive under-hood use including temperature cycling, humidity, and mechanical shock per JESD22 standards.
Low R_CE(sat) at high current	40 mΩ typical at 5 A enables <175 mW conduction loss, reducing heatsink requirements in space-constrained modules.
High h_FE stability	h_FE ≥ 100 maintained up to 100 °C junction temperature, ensuring consistent saturation across operating range.
Peak current capability	10 A single-pulse rating (t_p ≤ 10 ms) supports inrush current handling in motor startup and capacitor charging.

Applications

Fan & Motor Driver

Strobe Flash Unit

Use Scenario: Driving 24 V brushed DC cooling fans or small BLDC gate drivers in automotive ECUs.

IC Role / Device Role / Timing Role: Medium-power NPN switch controlling motor current path; operates in saturated mode during ON periods.

Use Value: Low V_CE(sat) minimizes power loss and thermal rise in compact ECU enclosures where forced air cooling is unavailable.

Use Scenario: High-current pulse switch for xenon or LED strobe flash in mobile phone camera modules.

IC Role / Device Role / Timing Role: Fast-turn-on saturated switch delivering 3–5 A pulses for <10 ms exposure duration.

Use Value: 10 A peak rating and 355 mV V_CE(sat) ensure full brightness without voltage droop or thermal throttling during burst mode.

TFT Display Inverter

Battery Charger Switch

Use Scenario: Backlight inverter primary-side switch in automotive TFT displays requiring 36 V input regulation.

IC Role / Device Role / Timing Role: High-voltage, medium-current switch in flyback or half-bridge topology operating at 50–200 kHz.

Use Value: 40 V V_CEO withstands reflected voltage spikes; low R_CE(sat) improves efficiency over discrete MOSFET alternatives in cost-sensitive designs.

Use Scenario: Input power switch or charge path controller in 12–24 V lead-acid or LiFePO₄ battery chargers.

IC Role / Device Role / Timing Role: Reverse-polarity protection or ON/OFF control switch placed between source and battery terminal.

Use Value: AEC-Q101 qualification ensures reliability in vehicle-mounted chargers; 150 °C T_j(max) supports operation near hot battery packs.

Equivalent & Alternatives

The following parts are listed as comparable options for similar NPN low V_CE(sat) transistor applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ON Semiconductor NSS40501UW3T1G	40 V V_CEO, 5 A I_C, R_CE(sat) = 45–85 mΩ, SOT-323 package (smaller, lower thermal mass)	Limited to ≤1.5 W P_tot; unsuitable for sustained >2 A loads without active cooling	Select when board space is critical and peak power <1 W; avoid for fan/motor drivers above 1.5 A continuous.
Diodes Incorporated DXT5551Q-13	40 V V_CEO, 4 A I_C, R_CE(sat) = 50–90 mΩ, SOT89 package, AEC-Q101 qualified	Slightly higher R_CE(sat) increases conduction loss by ~12 % at 5 A; identical thermal footprint	Drop-in replacement for cost-sensitive automotive programs where 10–15 mΩ R_CE(sat) penalty is acceptable.

Compared with PBSS4540X-QF, NSS40501UW3T1G trades thermal robustness for miniaturization, while DXT5551Q-13 matches the SOT89 form factor but delivers marginally higher conduction loss-making PBSS4540X-QF optimal for thermally constrained 4–5 A automotive switches requiring lowest possible V_CE(sat).

Availability

PBSS4540X-QF is available at Aetrix Electronics and suitable for automotive fan/motor drivers, battery charger power switches, and TFT display inverters requiring stable component supply, AEC-Q101 compliance, and repeatable thermal performance across production batches.

Supply support for PBSS4540X-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 high-volume, high-reliability discrete and logic devices, with leadership in automotive-qualified components and advanced packaging technologies.

PBSS4540X-QF belongs to Nexperia's Automotive Logic and Discrete portfolio, engineered specifically for medium-power switching in harsh-environment automotive subsystems where efficiency, thermal resilience, and qualification rigor are mandatory.

FAQ

Is PBSS4540X-QF pin-compatible with PBSS5540X-Q?

No. PBSS4540X-QF is an NPN transistor with pinout E-C-B (1-2-3), while PBSS5540X-Q is its PNP complement with reversed polarity and identical SOT89 mechanical footprint but inverted electrical behavior-requiring circuit redesign for substitution.

What is the maximum allowable base current for continuous operation?

The absolute maximum continuous base current is 1 A per datasheet limiting values. For reliable saturation at I_C = 4 A, a design base current of 200 mA (I_C/I_B = 20) is recommended, yielding V_CE(sat) ≤ 290 mV and maintaining h_FE stability.

Can PBSS4540X-QF be used in linear regulator pass transistor applications?

No. Its R_CE(sat) specification applies only in saturated switching mode; linear operation would exceed P_tot limits rapidly due to lack of Safe Operating Area (SOA) characterization for analog biasing-use only as a switch.

Does the "-QF" suffix indicate a different specification than "-Q"?

Yes. The "-QF" suffix denotes tape-and-reel packaging optimized for automated SMT placement (e.g., 3,000 pcs/reel), while electrical and thermal specifications remain identical to the base PBSS4540X-Q part; no parametric deviation exists.

PBSS4540X-QF Specifications

Product attributes: Attribute value

Manufacturer:: Nexperia USA Inc.

Series:: -

Package/Case:: TO-243AA

Packaging:: Tape & Reel (TR)

Product Status:: Active

Transistor Type:: NPN

Current - Collector (Ic) (Max):: 4 A

Voltage - Collector Emitter Breakdown (Max):: 40 V

Vce Saturation (Max) @ Ib, Ic:: 355mV @ 500mA, 5A

Current - Collector Cutoff (Max):: 100nA

DC Current Gain (hFE) (Min) @ Ic, Vce:: 300 @ 1A, 2V

Power - Max:: 550 mW

Frequency - Transition:: 70MHz

Operating Temperature:: 150°C (TJ)

Grade:: Automotive

Qualification:: AEC-Q101

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-89

PBSS4540X-QF FAQ

1.How can I place an order for PBSS4540X-QF through Aetrix?

Please submit a Request for Quotation (RFQ) for PBSS4540X-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 PBSS4540X-QF reliable?

The price and inventory of PBSS4540X-QF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for PBSS4540X-QF is usually 5 days.

3.What payment methods are accepted for PBSS4540X-QF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for PBSS4540X-QF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for PBSS4540X-QF?

PBSS4540X-QF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your PBSS4540X-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 PBSS4540X-QF?

For technical support, including PBSS4540X-QF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your PBSS4540X-QF requirements.

6.How does Aetrix verify that PBSS4540X-QF is sourced from the original manufacturer or authorized distributors?

All PBSS4540X-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 PBSS4540X-QF meets industry standards.

7.What is the process for return or replacement of PBSS4540X-QF?

All PBSS4540X-QF units undergo pre-shipment inspection (PSI). If there is an issue with PBSS4540X-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 PBSS4540X-QF part is unused and in its original packaging.

Return procedure for PBSS4540X-QF:

1.Submit a request within 90 days.

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

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